There follows the opinion of Judge Vance concurred in by Chief Judge Godbold and Judges Kravitch and Henderson. Judge Tjoflat specially concurs by separate opinion in which Judge Clark concurs in part. By separate opinion Judge Johnson joined by Judge Anderson concurs in the substantive portions (Parts I, II-A, III-A, III — B and III — C) of Judge Vance’s opinion, but dissents from Parts II-B and III — D, which relate to the disposition of this specific case on remand. As reflected in their respective opinions and concurrences a majority of the court, consisting of Chief Judge Godbold and Judges Tjoflat, Vance, Kravitch, Johnson, Henderson, Anderson and Clark, agree and it is therefore the judgment of the court that the district court’s judgment be reversed and the case remanded.
■ On remand the further proceedings in the district court shall be controlled by Parts I, II-A, III-A, III-B and III-C of Judge Vance’s opinion, all of which constitute the opinion of the court.
Judge Roney dissents in a separate opinion concurred in by Judges Hill and Fay. Judge Hill also filed a separate dissenting opinion.
REVERSED and REMANDED.
VANCE, Circuit Judge:In this opinion the en banc court addresses the proper standards for evaluating a claim of ineffective assistance of counsel based upon allegations of inadequate trial preparation. Petitioner-appellant David Leroy Washington appeals from the district court’s denial of his petition for a writ of habeas corpus under 28 U.S.C. § 2254. Washington has two primary contentions: (1) that his trial counsel did not render effective assistance because he failed to investigate, procure, and present character evidence relevant to the sentencing stage of his trial, and (2) that this failure prejudiced Washington in the conduct of his defense. We remand this case to the district court to determine whether trial counsel was ineffective under constitutional standards, and if so, whether Washington suffered actual and substantial prejudice.
I. Factual and Procedural Background
A. State Criminal Proceedings
During a ten-day period in September 1976 Washington committed a series of *1247crimes which included three brutal murders. On September 20, 1976 Washington and an accomplice stabbed to death a minister, David Pridgen. Three days later Washington broke into the house of Mrs. Katrina Birk. After binding Mrs. Birk and her three elderly sisters-in-law, he shot and stabbed each of them, killing Mrs. Birk and inflicting severe injuries upon the others.1 Finally, on September 29 Washington kidnapped Frank Meli, a twenty-year-old college student, and tied him to a bed with the help of two accomplices. After an attempt to extort ransom money from Meli’s family failed, Washington stabbed him to death. Each of these criminal episodes involved a substantial degree of preparation and each included acts of theft.
On October 1, 1976 Washington surrendered to Dade County police after his two accomplices were arrested for the murder of Frank Meli. He voluntarily confessed to the crime in a lengthy statement to the police. On October 7 the state indicted Washington for the Meli murder and appointed William Tunkey, an experienced criminal lawyer,2 to act as his attorney.
On November 5 Washington, acting against Tunkey’s advice, confessed to the Pridgen and Birk murders. Additional indictments were returned, and Washington’s trial was set for December 1 before Judge Richard Fuller.3 Washington waived his right to a jury trial and, again acting against the advice of Tunkey, pleaded guilty to all charges when he went before Judge Fuller. During the plea colloquy Washington stated that he did not have a significant prior criminal record and explained to Judge Fuller that his actions were the result of extreme stress and anxiety due to his unemployment and his corresponding inability to provide for his family. Washington stated, however, that he accepted responsibility for his crimes. Judge Fuller responded that he had “a great deal of respect for people who are willing to step forward and admit their responsibility.”
Washington also waived his right to have a sentencing jury. At the sentencing hearing on December 6 Tunkey adopted the testimony that Washington had given during the plea colloquy and argued that Washington’s evident remorse and his willingness to face the consequences of his actions should persuade the court to impose life imprisonment rather than death. Tun-key also successfully moved to exclude Washington’s “rap sheet” from evidence.
The judge specifically found, however, that even if Washington had no significant prior criminal record, the aggravating circumstances of the case would still “clearly far outweigh” the factors in mitigation. He therefore sentenced Washington to death on each of the three counts of first degree murder. He also sentenced Washington to consecutive terms of imprisonment for the other crimes. The death sentences were upheld on direct appeal. Washington v. State, 362 So.2d 658 (Fla.1978), cert. denied, 441 U.S. 937, 99 S.Ct. 2063, 60 L.Ed.2d 666 (1979).
B. Motion for Post-Conviction Relief in State Court
In March 1980 Washington, now represented by different counsel, moved for post-conviction relief in state circuit court. See Fla.R.Crim.P. 3.850. The primary focus of the motion was upon Tunkey’s failure to investigate fully and develop character evidence that might have been presented to Judge Fuller as a matter in mitigation. In support of the motion, Washington attached *1248fourteen affidavits from various friends, relatives, and acquaintances who stated that they would have testified on Washington’s behalf if his attorney had requested them to do so. He also attached reports from two psychiatrists who stated that “while [Washington] was not under the influence of extreme mental or emotional disturbance, he was chronically frustrated and depressed because of his economic dilemma wherein he was unable to find employment and provide for his wife and children.”
The Florida circuit court denied the motion without holding an evidentiary hearing.4 It found that Washington had failed to satisfy the test for ineffective assistance of counsel established in Knight v. State, 394 So.2d 997 (Fla.1981), which requires a defendant to prove that his attorney’s failure was a “substantial and serious deficiency measurably below that of competent counsel,” and that the failure caused “prejudice to the defendant to the extent that there is a likelihood that the deficient conduct affected the outcome of the court proceedings.” Id. at 1001 (citation omitted).5 On appeal the Florida Supreme Court affirmed, finding that “the appellant has failed under the Knight criteria to make a prima facie showing of substantial deficiency or possible prejudice and has failed to such a degree that we believe, to the point of moral certainty, that he is entitled to no relief under rule 3.850.”6 Washington v. State, 397 So.2d 285, 287 (Fla.1981).
C. Federal Habeas Proceedings in District Court
Having exhausted his state remedies, Washington sought habeas corpus relief from the district court below.7 Again, *1249the petition attacked Tunkey’s preparation for the sentencing phase of Washington’s trial.
Petitioner called Tunkey as a witness at the evidentiary hearing. Tunkey testified that after Washington confessed to the Pridgen and Birk murders, he experienced a feeling of “hopelessness” regarding the case, and that he believed there was little chance of Washington avoiding the death penalty. His strategy at that point was to introduce evidence of Washington’s emotional distress only during Washington’s plea colloquy with Judge Fuller, and thereafter to rely primarily upon an “attempt to convince the judge of Washington’s sincerity and frankness in pleading guilty.”8 Tunkey believed that this strategy might succeed in avoiding the death penalty because Judge Fuller had in other cases acknowledged his respect for people who un-qualifiedly admitted their responsibility.
Tunkey also testified that he made little attempt to develop evidence of Washington’s emotional distress apart from conversations with Washington in connection with his plea colloquy. Specifically, Tunkey did not follow up on initial telephone conversations with Washington’s wife and mother after they had failed to keep appointments with him. Additionally, he did not request a presentence report or a psychiatric investigation because he anticipated that they might reveal information more harmful than helpful to his client.
[R]ecognizing the potential weakness of hindsight analysis, I have not treated Judge Fuller’s testimony as determinative on the issue of prejudice. Rather, reviewing the proposed character and psychiatric testimony, and weighing it against the detailed record of petitioner’s conduct in initiating and carrying out three separate episodes of planned robbery, kidnapping and murder, there does not appear to be a likelihood, or even a significant possibility that the balancing of aggravating against mitigating circumstances under the Florida death penalty statute would have been altered in petitioner’s favor. Critically, the character and medical testimony cannot reasonably be characterized as evidence of extreme mental or. emotional disturbance. Nor does it provide persuasive rationalization for petitioner’s extended and calculated course of violence. Therefore, it is my determination on the critical legal issue, that petitioner was not prejudiced by the inaction which did occur, and was not denied his Constitutional right to effective .assistance of counsel, as that standard is defined under present case law.
The state called Judge Fuller as a witness. Over the strenuous objection of Washington’s counsel, the judge testified that evidence of the type contained in petitioner’s fourteen affidavits and two psychiatric reports would not have altered his determination that Washington deserved the death penalty.
The district court stated that the “central issue raised by the allegations is the assertion by petitioner that an adequate independent investigation by trial counsel would have revealed information and witnesses relevant to circumstances which may have mitigated the death sentence imposed.”9 Relying upon the decision of the former fifth circuit in Beavers v. Balkcom, 636 F.2d 114, 116 (5th Cir.1981), the court held that defense counsel in a capital case has a duty to investigate mitigating evidence irrespective of whether counsel’s strategy at trial would require the use of such evidence. The court therefore found that Tunkey had made an “error in judgment” by failing to conduct such an investigation thoroughly. It stopped short, however, of finding that Tunkey was ineffective, stating that the Constitution does not require errorless counsel. Rather than deciding vel non whether Tunkey was ineffective, the court found that Washington was not prejudiced by Tunkey’s error. In reaching that conclusion, the court held that Judge Fuller’s testimony demonstrated that there was no “likelihood that counsel’s inaction affected the outcome of the sentence” (citing United States v. Decoster, 624 F.2d 196, 208 (D.C.Cir.1979) (en banc)).10
*1250 D. The Panel Opinion
Washington appealed the judgment below to this court. The majority panel opinion contained three major holdings: (1) the district court should determine on remand whether Washington’s trial counsel was ineffective without regard to the prejudicial effect that may have resulted from counsel’s errors; (2) the district court, if it finds trial counsel was ineffective, should grant relief if petitioner proves that “but for his counsel’s ineffectiveness his trial, but not necessarily its outcome, would have been altered in a way helpful to him,” and the state fails to prove that the error was harmless beyond a reasonable doubt; and (3) in assessing the prejudicial impact of the counsel’s ineffectiveness, the district court should disregard Judge Fuller’s testimony that the additional evidence would not have affected his verdict.
This court chose to reconsider the case en banc in order to determine important questions regarding the duty of trial counsel to investigate and the burden upon a habeas petitioner to demonstrate prejudice resulting from ineffectiveness of counsel. We determine that under some circumstances when a strategic choice by counsel makes unnecessary a certain line of investigation, it is not required that effective counsel pursue that investigation. We also determine that a habeas petitioner must show that his counsel’s ineffectiveness caused “actual and substantial disadvantage” to the conduct of his defense. We remand this case to the district court for further proceedings consistent with this opinion.
II. Ineffectiveness of Counsel
The sixth amendment guarantees to criminal defendants the right to assistance of counsel. Gideon v. Wainwright, 372 U.S. 335, 83 S.Ct. 792, 9 L.Ed.2d 799 (1963). A vital corollary to this guarantee is the requirement of effective assistance of counsel, that is, counsel reasonably likely to render and rendering reasonably effective assistance given the totality of the circumstances. See, e.g., Herring v. Estelle, 491 F.2d 125, 127 (5th Cir.1974); MacKenna v. Ellis, 280 F.2d 592, 599 (5th Cir.1960), adhered to en banc, 289 F.2d 928 (5th Cir.), cert. denied, 368 U.S. 877, 82 S.Ct. 121, 7 L.Ed.2d 78 (1961). See also McMann v. Richardson, 397 U.S. 759, 771, 90 S.Ct. 1441, 1449, 25 L.Ed.2d 763 (1970). A petitioner who seeks to overturn his conviction on grounds of ineffective assistance of counsel must prove his entitlement to relief by a preponderance of the evidence.11 United States v. Killian, 639 F.2d 206, 210 (5th Cir.), cert. denied, 451 U.S. 1021, 101 S.Ct. 3014, 69 L.Ed.2d 394-(1981); Mays v. Balkcom, 631 F.2d 48, 52 n. 1 (5th Cir.1980); Marino v. United States, 600 F.2d 462, 464 (5th Cir.1979).12
*1251 A. The Duty to Investigate
Although the fate of a criminal defendant is determined at trial, the course of that trial can be decisively affected by actions of defense counsel in preparing the case. See, e.g., Moore v. United States, 432 F.2d 730, 739 (3d Cir.1970) (en banc). The courts have therefore insisted that effective counsel conduct a reasonable amount of pretrial investigation. See, e.g., Washington v. Watkins, 655 F.2d 1346, 1355-56 (5th Cir.1981), cert. denied, - U.S. -, 102 S.Ct. 2021, 72 L.Ed.2d 474 (1982); Davis v. Alabama, 596 F.2d 1214, 1217 (5th Cir.1979), vacated as moot, 446 U.S. 903, 100 S.Ct. 1827, 64 L.Ed.2d 256 (1980); Rummel v. Estelle, 590 F.2d 103, 104 (5th Cir.1979); Gaines v. Hopper, 575 F.2d 1147, 1149-50 (5th Cir.1978). Ultimately, the courts are concerned that counsels’ decisions reflect “informed, professional deliberation” rather than “inexcusable ignorance or senseless disregard of their clients’ rights.” United States v. Bosch, 584 F.2d 1113, 1122 (1st Cir.1978).
The amount of pretrial investigation that is reasonable defies precise measurement. It will necessarily depend upon a variety of factors including the number of issues in the case, the relative complexity of those issues, the strength of the government’s case, and the overall strategy of trial counsel. See, e.g., Washington v. Watkins, 655 F.2d at 1357; Wolfs v. Britton, 509 F.2d 304, 309 (8th Cir.1975). In making that determination, courts should not judge the reasonableness of counsel’s efforts from the omniscient perspective of hindsight, but rather “from the perspective of counsel, taking into account all of the circumstances of the case, but only as those circumstances were known to him at the time in question.” Washington v. Watkins, 655 F.2d at 1356.
The role of strategy in the calculus of reasonableness is of particular importance to this case. Tunkey testified that he made a strategic choice to introduce limited character evidence during the plea colloquy and thereafter to rely upon expressions of frankness, sincerity, and remorse to persuade the judge to impose a sentence of life imprisonment. In light of that strategy, Tunkey would have viewed as unnecessary an extensive investigation into Washington’s character. The district court did not evaluate the credibility of Tunkey’s testimony or the reasonableness of his strategy in light of available alternatives. Rather, the court concluded that Tunkey was obliged to conduct an extensive investigation of Washington’s character irrespective of whether his trial strategy would benefit from such investigation, and cited Beavers v. Balkcom, 636 F.2d at 116, in support of that conclusion. In his dissent from the panel opinion, Judge Roney relied, inter alia, upon Plant v. Wyrick, 636 F.2d 188, 189-90 (8th Cir.1980), for an apparently contrary proposition:
When a strategic choice of action makes unnecessary a certain line of investigation, it should not be necessary for effective counsel to pursue that investigation.
Washington v. Strickland, 673 F.2d 879, 908 (5th Cir.1982) (Roney, J., dissenting).
The conflicting language in cases such as Beavers and Plant reflects the different factual situations in those cases. Upon close examination, however, the rules of law contained in those cases are broadly consistent. In cases such as Plant, the trial counsel substantially investigated one plausible line of defense which he presented at trial, but did not investigate another line which he had chosen not to pursue at trial.13 In this class of eases, counsel made strategic choices of the general type that courts have traditionally respected in order to avoid undue interference with the adversary process. See, e.g., United States v. Decoster, *1252624 F.2d at 208. In cases such as Beavers, however, the trial counsel failed to conduct a substantial investigation into any plausible line of defense. In this class of cases counsel did not choose, strategically or otherwise, to pursue one line of defense over another. Instead, counsel simply abdicated his responsibility to advocate his client’s cause. See, e.g., Gomez v. Beto, 462 F.2d 596, 597 (5th Cir.1972).
In our canvass of the case law, we have identified five major lines of cases involving the duty to conduct adequate investigation before proceeding to trial.14 For the benefit of district courts that will confront future claims of ineffective assistance of counsel, we will discuss separately each line of cases and identify the proper role that counsel’s strategy plays in the evaluation of the reasonableness of pretrial investigation.
1. Counsel fails to conduct substantial investigation into the one plausible line of defense in the case.
In numerous cases effective counsel would discern only one plausible line of defense to serve his client’s interests. Whether that one line of defense is insanity, alibi, or simply putting the government to its proof, effective counsel is obliged to conduct a reasonably substantial investigation into that line before proceeding to trial. The failure to perform such an investigation is a clear example of a breach of the duty to investigate.
In Gomez v. Beto, 462 F.2d at 596, the defendant was prosecuted for a burglary that took place in Houston. The defendant contended that he was in San Antonio on the day of the crime and gave his attorneys the names of alibi witnesses. The attorneys failed to contact the witnesses and defendant was convicted. The court granted his motion for habeas corpus relief, stating:
These counsel knew that Gomez had only one possible defense to the charge: that he was in another city when the crime was committed.
When a defense counsel fails to investigate his client’s only possible defense, although requested by him to do so ... it can hardly be said that the defendant has had the effective assistance of counsel.
Id. at 597.15
It is obvious that an attorney can no more make a strategic decision that renders unnecessary an investigation of a defendant’s one plausible line of defense than he can make a strategic decision to plead guilty against his client’s wishes. See, e.g., Wiley v. Sowders, 647 F.2d 642, 649 (6th Cir.), cert. denied, 454 U.S. 1091, 102 S.Ct. 656, 70 L.Ed.2d 630 (1981); Mullins v. Evans, 473 F.Supp. 1321, 1325 (D.Colo.1979), aff’d, 622 F.2d 504 (10th Cir.1980). Cf. Wright v. Estelle, 572 F.2d 1071, 1082 (5th Cir.) (en banc) (Godbold, J., dissenting) (strategic choice by counsel that deprives defendant of his constitutional right to testify, absent knowing waiver by defendant, is not effective assistance of counsel), cert. denied, 439 U.S. 1004, 99 S.Ct. 617, 58 L.Ed.2d 680 (1978). Therefore, permissible trial strategy can never include the failure to conduct a reasonably substantial investigation into a defendant’s one plausible line of defense. See Ewing v. Williams, 596 F.2d 391, 398-99 (9th Cir.1979) (Ely, J., dissenting) (“a complete lack of preparation *1253and investigation [cannot] be deemed to be a ‘tactical decision’ made by the attorney”); Wood v. Zahradnick, 430 F.Supp. 107, 112 (E.D.Va.1977) (where defenses based upon mental condition were the only plausible line of defense, “the [c]ourt can envision no tactical reason why these defenses were not explored”), aff’d in relevant part, 578 F.2d 980 (4th; Cir.1978).
2. Counsel conducts a reasonably substantial investigation into the one line of defense that is presented at trial.
In this class of decisions we again deal with cases in which effective counsel would discern only one plausible line of defense or in which he chooses to rely upon only one major line of defense. An attorney who conducts a reasonably substantial investigation into that line of defense before it is presented at trial is often criticized by his client after the defense proves unsuccessful for not having conducted a more extensive investigation. Courts have emphasized that “counsel for a criminal defendant is not required to pursue every path until it bears fruit or until all conceivable hope withers.” Lovett v. Florida, 627 F.2d 706, 708 (5th Cir.1980). See also Baty v. Balkcom, 661 F.2d 391, 395 n. 8 (5th Cir.1981); Williams v. Maggio, 679 F.2d 381, 393 (5th Cir.1982) (Unit A en banc); Cox v. Wyrick, 642 F.2d 222, 226-27 (8th Cir.), cert. denied, 451 U.S. 1021, 101 S. Ct. 3013, 69 L.Ed.2d 394 (1981); United States v. Decoster, 624 F.2d at 210-11. Rather, attorneys must conduct a substantial investigation which includes “an independent examination of the facts, circumstances, pleadings and laws involved.” Rummel v. Estelle, 590 F.2d at 104; United States v. Moore, 554 F.2d 1086, 1092-93 (D.C.Cir.1976).
The question whether counsel conducted a reasonable amount of investigation prior to presenting the one line of defense at trial does not typically involve strategic choices. Once the choice has been made to rely upon one defense at trial, counsel is of course obliged to make a reasonable, though not necessarily exhaustive, investigation before trial.16
3. Counsel conducts a reasonably substantial investigation into all plausible lines of defense and chooses to rely upon fewer than all of them at trial.
In this class of cases effective counsel would discern more than one plausible line of defense to serve his client’s interests. Certain of the lines might be presented at trial in tandem. For instance, an attorney might challenge the racial composition of the grand jury venire and raise an alibi defense where both appear to be plausible. Other lines of defense may be contradictory and thus incapable of being presented persuasively in tandem. For instance, an attorney might not present an alibi defense in conjunction with a justifiable homicide defense.17
Before making a strategic choice as to which lines of defense to employ at trial, counsel should ideally conduct a substantial investigation into each potential line. In this way he would be able to assess with a considerable degree of professional accuracy which lines are most likely to succeed at trial. He would be able to discuss thoroughly the options with his client. For these reasons, the American Bar Associa*1254tion has suggested that criminal defense counsel “conduct appropriate investigations, both factual and legal, to determine what matters of defense can be developed/’ American Bar Association, Project on Standards for Criminal Justice, Standards Relating to the Defense Function (App.Draft 1971) [hereinafter referred to as American Bar Association Standards]; see Coles v. Peyton, 389 F.2d 224, 226 (4th Cir.) (applying identical standard), cert. denied, 393 U.S. 849, 89 S.Ct. 80, 21 L.Ed.2d 120 (1968).
When an attorney makes a strategic choice after satisfying this rigorous and extensive duty to investigate, courts will seldom if ever find that the choice was the result of ineffective assistance of counsel. Our adversary system of justice requires that attorneys be permitted to exercise informed discretion in the conduct of the client’s defense. United States v. Decoster, 624 F.2d at 208. See also United States v. Guerra, 628 F.2d 410, 413 (5th Cir.1980), cert. denied, 450 U.S. 934, 101 S.Ct. 1398, 67 L.Ed.2d 369 (1981); Marino v. United States, 600 F.2d at 463; Williams v. Maggio, 679 F.2d at 393.18 If an attorney makes a strategic choice to rely upon one line of defense rather than another, and that choice is based upon the exercise of professional judgment after a reasonably substantial investigation into all plausible lines of defense, the courts will find ineffective assistance of counsel only if the choice was so patently unreasonable that no competent attorney would have made it. Cf. United States ex rel. Robinson v. Pate, 312 F.2d 161, 162 (7th Cir.1963) (counsel not ineffective because strategic choice was one about which competent attorneys might honestly disagree).
4. Counsel fails to conduct a substantial investigation into one plausible line of defense because of his reasonable strategic choice to rely upon another plausible line of defense at trial.
As observed above, when effective counsel would discern several plausible lines of defense he should ideally perform a substantial investigation into each line before making a strategic decision as to which lines he will employ at trial. This ideal, as expressed in the American Bar Association Standards, is an aspiration to which all defense counsel should strive. It does not, however, represent the constitutional minimum for reasonably effective assistance of counsel. See United States v. Decoster, 624 F.2d at 205, 210-11. See also Cooper v. Fitzharris, 586 F.2d 1325, 1330 (9th Cir. 1978) (en banc), cert. denied, 440 U.S. 974, 99 S.Ct. 1542, 59 L.Ed.2d 793 (1979); United States v. Moore, 554 F.2d at 1093 (Robb, J., concurring) (both opinions criticize checklist approach to evaluating performance of counsel). Realistically, given the finite resources of time and money that are available to defense counsel, fewer than all plausible lines of defense will be the subject of substantial investigation. Often, counsel will make a choice of trial strategy relatively early in the representation process after conferring with his client, reviewing the state’s evidence, and bringing to bear his experience and professional judgment.19 Thereafter he will concentrate his finite resources on investigating those lines of defense upon which he has chosen to rely.
The choice by counsel to rely upon certain lines of defense to the exclusion of others *1255before investigating all such lines is a strategic choice. See, e.g., Gray v. Lucas, 677 F.2d 1086, 1093 (5th Cir.1982). The basis for judicial deference to such a choice, however, is eroded measurably. See Note, Effective Assistance of Counsel for the Indigent Defendant, 78 Harv.L.Rev. 1434, 1439 (1965). Whereas a strategy chosen after full investigation is entitled to almost automatic approval by the courts, a strategy chosen after partial investigation must be scrutinized more closely in order to safeguard the rights of criminal defendants.
A strategy chosen without the benefit of a reasonably substantial investigation into all plausible lines of defense is generally based upon counsel’s professional assumptions regarding the prospects for success offered by the various lines. The cases generally conform to a workable and sensible rule: when counsel’s assumptions are reasonable given the totality of the circumstances and when counsel’s strategy represents a reasonable choice based upon those assumptions, counsel need not investigate lines of defense that he has chosen not to employ at trial.20
In Washington v. Watkins the attorney for a defendant charged with capital murder relied primarily upon an alibi defense. When that defense proved unsuccessful and defendant was sentenced to death, the defendant sought habeas corpus relief because, inter alia, his attorney failed “to investigate the apparent under-representation of blacks on the relevant jury panels .. .. ” 655 F.2d at 1364. At the evidentia-ry hearing in district court, the attorney was asked why he failed to conduct this investigation. He responded that based upon his prior experience with juries in Columbus, Mississippi and based upon his observation of the tactics of other attorneys, he assumed that a challenge based upon the racial composition of the jury panels would be “without merit.” Id. at n. 36. The court found that in light of these circumstances, counsel’s strategic decision to devote his efforts to the alibi defense “was not so ill-chosen that it made [his] overall representation constitutionally ineffective.” 655 F.2d at 1364. In numerous other cases, courts have similarly found that a reasonable strategic choice based upon reasonable assumptions makes it unnecessary to investigate other plausible lines of defense that counsel does not rely upon at trial.21
*1256On the other hand, courts have not hesitated to find counsel ineffective when his failure to investigate is not based upon a reasonable set of assumptions or when the strategic choices made by counsel on the basis of those assumptions are not reasonable. The California case of In re Saunders, 2 Cal.3d 1033, 88 Cal.Rptr. 633, 472 P.2d 921 (1970), furnishes an excellent illustration. In Saunders the defendant participated in an armed robbery which resulted in the murder of a store clerk. He was tried for capital murder and counsel was appointed to defend him. Two months before trial the defendant and his mother informed counsel that the defendant had previously suffered head injuries that resulted in organic brain damage. Although the attorney was aware that this information was relevant to the diminished capacity defense under California law, he never investigated the matter. Instead, he relied exclusively upon an argument that defendant did not actually commit the shooting.
The attorney later testified that he failed to investigate the diminished capacity line of defense before trial because he had made a strategic choice to preserve that argument for the clemency hearing. The California Supreme Court overturned the conviction. It found that a reasonable attorney would have recognized that diminished capacity was a very promising line of investigation in light of the information furnished to counsel by defendant and his mother. It also found that a reasonable attorney would not have made the strategic choice to rely upon the weak defense used to the exclusion of the diminished capacity defense.22
In sum, an attorney who makes a strategic choice to channel his investigation into fewer than all plausible lines of defense is effective so long as the assumptions upon which he bases his strategy are reasonable and his choices on the basis of those assumptions are reasonable.23
*12575. Counsel fails to conduct a substantial investigation into plausible lines of defense for reasons other than strategic choice.
When an attorney fails to conduct a substantial investigation into any of his client’s plausible lines of defense, the attorney has failed to render effective assistance of counsel. The attorney equally fails to render effective assistance when he chooses among several plausible lines of defense, thereby excluding certain of them, for no strategic reason.
The clearest example of this breach of the duty to investigate appears in Gaines v. Hopper, 575 F.2d at 1147. In that case the attorney’s policy against interviewing any witnesses before trial left him “in no- better position than his jailed client to evaluate the legal and factual realities of the case .... ” Id. at 1149. The attorney did not channel his investigation on the basis of a professional assessment of the prospects for success. Rather, he abandoned his obligation to develop a case for his client. See also Powell v. Alabama, 287 U.S. 45, 58, 53 S.Ct. 55, 60, 77 L.Ed. 158 (1932); United States v. Hinton, 631 F.2d 769, 780 (D.C.Cir. 1980); United States v. Porterfield, 624 F.2d 122, 125 (10th Cir.1980); United States v. Bosch, 584 F.2d at 1122.24
In many cases it will not be clear whether the failure to investigate a line of defense is based upon trial strategy or upon neglect of counsel’s professional obligations. Courts presume, in accordance with the general presumption of attorney competence, that counsel’s actions are strategic. See, e.g., Michel v. Louisiana, 350 U.S. 91, 101, 76 S.Ct. 158, 164, 100 L.Ed. 83 (1955); Marino v. United States, 600 F.2d at 463; Tuttle v. Decker, 386 F.2d 814, 816 n. 1 (5th Cir. 1967); Cowens v. Wainwright, 373 F.2d 34, 34 (5th Cir.), cert. denied, 387 U.S. 913, 87 S.Ct. 1701, 18 L.Ed.2d 635 (1967); United States v. Aulet, 618 F.2d 182, 189 (2d Cir.1980). Cf. The Supreme Court, 1976 Term, 91 Harv.L.Rev. 70, 219 (1977) (noting the presumption of strategic choice in sixth amendment cases and suggesting another rule in cases involving the determination of “deliberate bypass”). This presumption can be rebutted, however, when trial counsel testifies credibly at an evidentiary hearing that his choice was not strategic, see, e.g., *1258Beckham v. Wainwright, 639 F.2d 262, 265-66 (5th Cir.1981); Marzullo v. Maryland, 561 F.2d 540, 547 (4th Cir.1977), cert. denied, 435 U.S. 1011, 98 S.Ct. 1885, 56 L.Ed.2d 394 (1978), or when certain of counsel’s actions do not conform to a general pattern of a rational trial strategy. See, e.g., Baty v. Balkcom, 661 F.2d at 395; Nero v. Blackburn, 597 F.2d 991, 994 (5th Cir.1979); United States v. Bosch, 584 F.2d at 1121-22.
B. The Need for a Remand
In this case the district court stated that Tunkey was obligated to investigate substantially a line of defense based upon emotional distress irrespective of whether Tun-key’s trial strategy made that investigation necessary. The district court’s legal premise was incomplete. If, in fact, there was more than one plausible line of defense in the case; if Tunkey made a strategic choice based upon reasonable assumptions to pursue one line of defense at the expense of another; and if that strategic choice was reasonable, Tunkey did not breach his duty to investigate.
When district courts fail to make findings or do so' on the basis of an erroneous perception of the. law, courts of appeals ordinarily remand the case “unless the record permits only one resolution of the factual issue.” Pullman-Standard v. Swint, 456 U.S. -, -, 102 S.Ct. 1781, 1791-92, 72 L.Ed.2d 66 (1982). In this case numerous factual issues remain to be resolved by the district court before it can be determined with certainty whether counsel was reasonably effective. We therefore remand this case for it to make findings on these factual issues.
III. The Showing of Prejudice
If the district court finds on remand that Washington’s right to effective assistance of counsel was violated, it should then separately determine' whether Washington suffered prejudice of sufficient magnitude to warrant granting the writ of ha-beas corpus. We decide that the petitioner has the burden of persuasion to demonstrate that the ineffective assistance created not only “a possibility of prejudice, but that [it] worked to his actual and substantial disadvantage.” See United States v. Frady, 456 U.S. 152, 170, 102 S.Ct. 1584, 1596, 71 L.Ed.2d 816 (1982) (emphasis in original).25 If he successfully satisfies this burden, the writ must be granted unless the state proves that counsel’s ineffectiveness was harmless beyond a reasonable doubt. See Chapman v. California, 386 U.S. 18, 87 S.Ct. 824, 17 L.Ed.2d 705 (1967). We proceed to examine the basis for this holding.
A. The Need for a Prejudice Requirement
We are confronted at the outset with Washington’s contention that the courts should find ineffective assistance of counsel prejudicial per se. Under petitioner’s proposed rule, the writ would issue automatically upon petitioner’s showing of ineffective assistance. In support of this rule, Washington cites numerous cases including Gideon v. Wainwright, 372 U.S. at 335, 83 S.Ct. 729, Geders v. United States, 425 U.S. 80, 96 S.Ct. 1330, 47 L.Ed.2d 592 (1976), and Cuyler v. Sullivan, 446 U.S. 335, 100 S.Ct. 1708, 64 L.Ed.2d 333 (1980). We find that these cases are instantly distinguishable.
In Gideon v. Wainwright the state refused to appoint counsel to assist in the defense of an indigent defendant. This absolute deprivation of the right to counsel is so inherently prejudicial that the courts will not conduct a particularized inquiry into whether harm was realized in a particular case. See Chapman v. California, 386 U.S. at 43, 87 S.Ct. at 837 (Stewart, J., concurring).
*1259In Geders the trial court ordered a defendant not to consult with his attorney during an overnight recess after his direct examination and before his cross-examination. While the defendant did not suffer a total deprivation of the right to counsel, the trial court’s action constituted direct state interference with important aspects of the attorney’s representation of his client. See also Herring v. New York, 422 U.S. 853, 95 S.Ct. 2550, 45 L.Ed.2d 593 (1975); Brooks v. Tennessee, 406 U.S. 605, 92 S.Ct. 1891, 32 L.Ed.2d 358 (1972); Ferguson v. Georgia, 365 U.S. 570, 81 S.Ct. 756, 5 L.Ed.2d 783 (1961); Powell v. Alabama, 287 U.S. at 45, 53 S.Ct. 55. Although such limited interference is not inherently prejudicial, a rule of automatic reversal serves to deter the state from engaging in action that poses a direct threat to the defendant’s right to effective assistance of counsel. See United States v. Decoster, 624 F.2d at 201.
Finally, in cases such as Cuyler the defendant was represented by an attorney who functioned under an actual conflict of interest. This impediment to effective representation was neither inherently prejudicial nor the product of direct state interference in the representation process. The Supreme Court granted automatic reversal, however, because the subtle and pervasive effect of conflicting loyalties upon an attorney would necessarily make any inquiry into prejudice an exercise in “unguided speculation.” Holloway v. Arkansas, 435 U.S. 475, 491, 98 S.Ct. 1173, 1182, 55 L.Ed.2d 426 (1978); see Glasser v. United States, 315 U.S. 60, 75-76, 62 S.Ct. 457, 467, 86 L.Ed. 680 (1942).
In this case Washington did not suffer the inherent prejudice that attended the total deprivation of counsel in Gideon. Nor does he complain of state interference in the attorney-client relationship as was evident in Geders. Rather, he contends that the attorney provided to him by the state, a . competent and experienced criminal lawyer, rendered assistance that was below the standard of reasonably effective counsel. Unlike the defendant in Cuyler, Washington does not contend that this ineffectiveness resulted from any subtle or pervasive impediment to Tunkey’s performance. Rather, he contends that Tunkey committed several discrete errors of omission and commission that reasonably effective counsel would not have committed. The process of identifying and the evaluating the effect of these individual errors is not an exercise in “unguided speculation.” Rather, the inquiry into whether these errors resulted in harm is a task that the district courts are well suited to perform. See Davis v. Alabama, 596 F.2d at 1222-23; United States v. Decoster, 624 F.2d at 201-03 (plurality opinion), 257-58 (Robinson, J., concurring); Cooper v. Fitzharris, 586 F.2d at 1332; United States ex rel. Green v. Rundle, 434 F.2d 1112, 1115 (3d Cir.1970). See also Chambers v. Maroney, 399 U.S. 42, 54, 90 S.Ct. 1975, 1982, 26 L.Ed.2d 419 (1970) (relief for ineffective assistance of counsel denied where “the claim of prejudice was without substantial basis”).26 Accordingly, we conclude that no Supreme Court decision requires a finding of per se prejudice in this type of case. We also perceive several strong considerations that militate against creating such a rule.
First, a rule of per se prejudice would be contrary to the teachings of United States v. Morrison, 449 U.S. 361, 364-65, 101 S.Ct. 665, 668, 66 L.Ed.2d 564 (1981), that the remedy for a violation of defendant’s right to adequate assistance of counsel should be tailored to the harm caused by that violation. The defendant in Morrison demonstrated “no prejudice of any kind” and the Court found:
There is no effect of a constitutional dimension which needs to be purged to make certain that respondent has been effectively represented and not unfairly convicted. The Sixth Amendment violation, if any, accordingly provides no justification for interfering with the criminal proceedings against [defendant].
*1260Id. at 366-67, 101 S.Ct. at 669. Washington’s proposed rule of per se prejudice would require the unwarranted interference in criminal proceedings that Morrison expressly forbids.27
Additionally, a rule of per se prejudice is especially inappropriate in the case of ineffective assistance because the state is not responsible for the violation of the petitioner’s rights. Since the rule would not serve to deter the state from any unconstitutional course of action, the sole effect of the rule would be to bestow an undeserved windfall upon criminal defendants who were not harmed by the errors of their attorneys. See Note, supra, at 1436-37.28
Finally, the proposed rule would distort the function of the writ of habeas corpus under 28 U.S.C. § 2254. The writ exists to redress fundamental unfairness in state criminal proceedings. Rose v. Lundy, 455 U.S. 509, 543, 102 S.Ct. 1198, 1216, 71 L.Ed.2d 379 (1982) (Stevens, J., dissenting). See also Lehman v. Lycoming County Children’s Services Agency, 458 U.S. -, -, 102 S.Ct. 3231, 3239-40, 73 L.Ed.2d 928 (1982). A particularized inquiry must be made in cases of ineffective assistance of counsel to determine whether the fundamental unfairness that the writ was intended to redress exists in an individual case. See Nelson v. Estelle, 642 F.2d 903, 906 (5th Cir.1981); United States v. Decoster, 624 F.2d at 207.
B. Allocation of the Burden of Proof
1. The Chapman Standard
Having determined that there must be a showing of prejudice, it remains for us to allocate the burden of proof on this issue. For many constitutional violations the existence of prejudice is presumed, and the state can rebut it only upon a showing of harmlessness beyond a reasonable doubt. See Chapman v. California, 386 U.S. at 24, 87 S.Ct. at 82829 In certain respects, however, the violation of a defendant’s right to effective assistance of counsel is sui generis. See, e.g., McQueen v. Swenson, 498 F.2d 207, 218 (8th Cir.1974). The violation is not caused by the state. Consequently, the harsh burden of proof in Chapman, which is meant to prevent the state from benefiting from its own wrongs, does not serve the same equitable and deterrent function in cases of ineffective assistance of counsel. *1261Id. at 219. Additionally, where ineffectiveness is predicated upon the failure of counsel to raise certain objections, application of the Chapman rule would relieve petitioner of the requirement that he show prejudice before he can raise those objections on collateral review. Cooper v. Fitzharris, 586 F.2d at 1333. See generally United States v. Frady, 456 U.S. at 170, 102 S.Ct. at 1596.30 Alternatively, when counsel is faulted for his failure to develop and present a certain line of evidence, application of the Chapman rule would require the state to, prove that the failure to produce certain evidence was harmless beyond a reasonable doubt, even though the evidence is more readily accessible to the petitioner. See United States v. Valenzuela-Bernal, 458 U.S. -, -, 102 S.Ct. 3440, 3448-49, 73 L.Ed.2d 1193 (1982); United States v. Decoster, 624 F.2d at 228 (MacKinnon, J., concurring); Coles v. Peyton, 389 F.2d at 230 (Craven, J., dissenting).31
For these reasons, we believe that application of the Chapman standard without an initial showing of harm by the petitioner would be ill-advised.
2. The Decoster Standard
In Wright v. Estelle, Chief Judge God-bold stated:
in this circuit, we have consistently held that one suffering inadequate counsel need not show to receive a new trial that adequate counsel would change the result on retrial.
572 F.2d at 1084 (Godbold, J., dissenting). The plurality opinion in United States v. Decoster, however, requires the petitioner to prove precisely that. 624 F.2d at 208, 211-12; see supra note 5. We reject the outcome-determinative test in Decoster for reasons analogous to those that lead us to reject the Chapman standard. First, in cases where the allegation of ineffective assistance is based upon counsel’s failure to raise certain objections, the Decoster test requires the petitioner to carry a burden of showing prejudice that is different from and greater than the analogous burden in the “cause and prejudice” formulation of Wainwright v. Sykes, 433 U.S. 72, 87, 97 S.Ct. 2497, 2506, 53 L.Ed.2d 594 (1977). Application of the Decoster rule may thus have the surprising result of holding a petitioner who has established a deprivation of his constitutional right to effective assistance of counsel to a greater showing of prejudice than if he was merely trying to present a claim of constitutional error not raised in the state courts.32
*1262Additionally, when counsel is faulted for failing to develop a certain line of evidence, Decoster would require the petitioner to demonstrate, first, what evidence would have been produced and, second, that in the context of the entire case the additional evidence would have altered the result. While the first showing is properly allocated to the petitioner because he is better situated to show what evidence could be uncovered in his favor, he is no better situated than the state to demonstrate that the new evidence was likely to alter the outcome of the case. We believe that where the petitioner has shouldered the considerable burden of showing a violation of his sixth amendment rights that resulted in actual and substantial disadvantage to his case, it is inequitable to encumber him with the further responsibility of showing that the disadvantage determined the outcome of the entire case. See McQueen v. Swenson, 498 F.2d at 220.
3. The Panel Majority
The panel majority attempted to steer between the Scylla and Charybdis of Chapman and Decoster by imposing upon the petitioner the burden of showing that “but for his counsel’s ineffectiveness his trial, but not necessarily its outcome, would have been altered in a way helpful to him.” Washington v. Strickland, 673 F.2d at 902. We are now convinced that this standard does not represent a significant improvement upon the Chapman standard. A decision of the Supreme Court handed down shortly after the publication of the panel opinion discussed the practical effect of a prejudice standard similar to the panel majority’s standard. In United States v. Valenzuela-Bernal the defendant claimed that the government violated his rights under the compulsory process clause of the sixth amendment by deporting individuals who would have offered testimony in his defense. The court of appeals overturned his conviction after the defendant made a showing that the witnesses’ expected testimony was of “conceivable benefit” to the defendant. The Supreme Court characterized this test as a virtual per se rule:
Given the vagaries of a typical jury trial, it would be a bold statement indeed to say that the testimony of any missing witness could not have “conceivably benefited” the defense. To us, the number of situations which will satisfy this test is limited only by the imaginations of judges or defense counsel.
458 U.S. at -, 102 S.Ct. at 3446 (footnote omitted).
We believe it is equally true given the “vagaries of a typical jury trial” that virtually any new piece of favorable evidence produced by a petitioner at a habeas hearing may be “helpful to him.” We therefore reject the test of the panel majority.
4. Actual and Substantial Detriment
The test for prejudice in Frady suggests the proper allocation of the burden of proof on the issue of prejudice. In order to sustain that burden, the petitioner must show that ineffectiveness of counsel resulted in actual and substantial disadvantage to the course of his defense. This burden is of sufficient magnitude to discourage the filing of insubstantial claims and to focus the attention of the district court on the actual harm suffered by the petitioner as a result of his counsel’s performance. At the same time, the burden does not require the petitioner to produce evidence to which he is unlikely to have access. It also properly reserves for the state the ultimate burden of showing that any constitutional error that did occur was harmless beyond a reasonable doubt. Thus, even if the defense suffered actual and substantial disadvantage, the state may show in the context of all the evidence that it remains certain beyond a reasonable doubt that the outcome of the proceedings would not have been altered but for the ineffectiveness of counsel. See generally Chapman v. California, 386 U.S. at 24, 87 S.Ct. at 828.
C. Testimony of Judge Fuller
In reaching its decision that Washington did not suffer prejudice, the district court considered testimony from Judge *1263Fuller, the state trial judge who imposed the death penalty. The district court could properly consider that testimony to the extent that it contains personal knowledge of historical facts or expert opinion. See 10 J. Moore & H. Bendix, Moore’s Federal Practice § 605.02 (1982). We decide, however, that the portion of Judge Fuller’s testimony in which he explained his reasons for imposing the death sentence and his probable response to the evidence adduced at the habeas hearing is inadmissible evidence that may not be considered by the district court.
It is a firmly established rule in our jurisprudence that a judge may not be asked to testify about his mental processes in reaching a judicial decision. In Fayerweather v. Ritch, 195 U.S. 276, 25 S.Ct. 58, 49 L.Ed. 193 (1904), the Supreme Court held:
[T]he testimony of the trial judge, given six years after the case had been disposed of, in respect to matters he considered and passed upon, was obviously incompetent. True, the reasoning of the court for the rule [prohibiting testimony by jurors] is not wholly applicable, for as the case was tried before a single judge there were not two or more minds coming by different processes to the same result. Nevertheless no testimony should be received except of open and tangible facts — matters which are susceptible of evidence on both sides. A judgment is a solemn record. Parties have a right to rely upon it. It should not lightly be disturbed, and ought never to be overthrown or limited by the oral testimony of a judge or juror of what he had in mind at the time of the decision.
Id. at 306-07, 25 S.Ct. at 67-68. See also United States v. Crouch, 566 F.2d 1311, 1316 (5th Cir.1975).
There are several strong policy reasons that counsel continued adherence to this rule. First, such testimony poses special risks of inaccuracy. The testimony is often given several years after the fact and a judge is unlikely to be able to reconstruct his thought processes accurately over such a span of time. Second, the finality and integrity of judgments would be threatened by a rule that enabled parties to attack a judgment by probing the mental processes of a judge. Similar considerations underlie the rule against probing the mental processes of jurors. See United States v. D’Angelo, 598 F.2d 1002, 1004-05 (5th Cir.1979); Fed.R.Evid. 606(b).
Finally, a rule that allows the probing of the mental processes of a state judge would exacerbate certain problems that are already inherent in the habeas corpus context. The tendency of the habeas proceeding to detract from “the perception of the trial of a criminal case in state court as a decisive and portentous event,” Wainwright v. Sykes, 433 U.S. at 90, 97 S.Ct. at 2508, is enhanced by the prospect that the state trial judge may be called into federal court several years later to recreate his thought processes at the criminal trial. Additionally, the friction between the state and federal systems of justice can hardly be alleviated by a rule that permits the parties to interrogate a state judge in federal court regarding the basis for his decision. See, e.g., Rose v. Lundy, 455 U.S. at 518, 102 S.Ct. at 1203; Sumner v. Mata, 449 U.S. 539, 550 & n. 3, 101 S.Ct. 764, 771 & n. 3, 66 L.Ed.2d 722 (1981).
D. The Need for a Remand
The district court purported to apply the test in Decoster to determine that the petitioner failed to sustain his burden of showing prejudice. It also considered testimony from Judge Fuller regarding his mental processes in reaching his verdict. Since we reject the Decoster rule and find that one portion of Judge Fuller’s testimony was inadmissible, it is necessary to remand the case to the district court for further findings. See Pullman-Standard v. Swint, 456 U.S. at -, 102 S.Ct. at 1791-92.
IV. Conclusion
On remand, the district court should initially determine whether Washington’s right to effective assistance of counsel was violated. If the district court finds a violation, it should then determine whether the petitioner suffered actual and *1264substantial detriment to the conduct of his defense.33 Finally, if the petitioner meets this twin burden, the district court must determine whether, in the context of the entire case, the detriment suffered was harmless beyond a reasonable doubt.34 The district court may, in its discretion, conduct further proceedings.
. One of the injured women remained unconscious for over a year before she died.
. In its order denying Washington’s motion for postconviction relief, the court for the eleventh judicial circuit of Florida characterized Tunkey as “one of the leading criminal defense attorneys in Dade County .... ”
.Tunkey anticipated that the state would attempt to use Washington’s conviction in connection with the Pridgen murder to furnish an additional aggravating circumstance in the Birk and Meli cases pursuant to section 921.-141(5)(b) of the Florida statutes. He successfully moved to prevent use of the Pridgen case in this manner. Tunkey also made a motion for a continuance which was denied by Judge Fuller.
. With respect to the affidavits, the court found that “the best that could be said ... is that these individuals could have testified that the Defendant was a basically good person who had not been in trouble with the law on prior , occasions and that he was worried about his family because of his financial difficulties at the time of these murders, a fact that was testified to by the defendant himself at the plea colloquy.” The court also found that the new psychiatric reports might actually have harmed Washington’s case because they conclusively established the absence of the statutory mitigating circumstance of extreme mental or emotional disturbance. The court stated that the course actually pursued by Tunkey, to put on evidence of emotional distress only during the plea colloquy, served Washington’s interests by preventing the state from presenting more damaging evidence in cross-examination or rebuttal. The court particularly noted that numerous assertions in the affidavits that Washington had never committed a crime before the ten-day period in September 1976 could have been thoroughly rebutted by the state.
. In Knight the Florida Supreme Court drew heavily upon the plurality opinion in United States v. Decoster, 624 F.2d 196 (D.C.Cir.1979) (en banc), in which the court stated:
[T]he accused must bear the initial burden of demonstrating a likelihood that counsel’s inadequacy affected the outcome of the trial. Id. at 208.
. The panel opinion inadvertently misquoted the Florida Supreme Court and gave the impression that the supreme court had only affirmed the circuit court’s finding that no prejudice resulted from Tunkey’s conduct. See Washington v. Strickland, 673 F.2d 879, 884 (5th Cir.1982). In fact the supreme court affirmed the circuit court’s decision on both of its stated grounds: that Tunkey’s representation was not seriously deficient and that in any case Washington was not prejudiced.
.The grounds for relief in addition to the ineffectiveness claim are recounted in the panel opinion. See Washington v. Strickland, 673 F.2d 879, 885-86 n. 3 (5th Cir.1982). One further claim for relief, based upon Gardner v. Florida, 430 U.S. 349, 97 S.Ct. 1197, 51 L.Ed.2d 393 (1977), was raised for the first time at the evidentiary hearing in the district court below. Arguably, therefore, Washington’s petition is a “mixed petition” that contains both exhausted and unexhausted claims. Generally, mixed petitions must be dismissed without prejudice while the petitioner pursues his unexhausted claims in state court. Rose v. Lundy, 455 U.S. 509, 510, 102 S.Ct. 1198, 1199, 71 L.Ed.2d 379 (1982); Galtieri v. Wainwright, 582 F.2d 348, 355 (5th Cir.1978) (en banc). There are, however, exceptions to the exhaustion doctrine. Id. at 354. In this case the district court found that Washington’s petition came within such an exception, and the State of Florida does not dispute the district court’s finding on appeal. Since the exhaustion requirement is a matter of comity rather than a matter of jurisdiction, see Rose v. Lundy, 455 U.S. at 518-20, 102 S.Ct. at 1203-04; Stinson v. Alabama, 585 F.2d 748, 748 (5th Cir.1978), the court of appeals will not dismiss the petition sua sponte in this case. We adopt the conclusion of the *1249panel that the district court properly found that the Gardner claim was without merit. See Washington v. Strickland, 673 F.2d at 889 n. 5.
. Opinion of district court at 7.
. Id. at 9.
. Id. at 16-17. The court also stated that it did not consider the testimony of Judge Fuller to be determinative on the issue of prejudice:
. This burden of persuasion can be phrased alternatively as the burden to rebut the presumption of attorney competence. See Michel v. Louisiana, 350 U.S. 91, 101, 76 S.Ct. 158, 164, 100 L.Ed. 83 (1955); Cox v. Wyrick, 642 F.2d 222, 226 (8th Cir.), cert. denied, 451 U.S. 1021, 101 S.Ct. 3013, 69 L.Ed.2d 394 (1981); United States v. Garcia, 625 F.2d 162, 170 (7th Cir.), cert. denied, 449 U.S. 923, 101 S.Ct. 325, 66 L.Ed.2d 152 (1980).
. Washington urges us to apply a special set of rules regarding ineffective assistance of counsel to capital cases. The court has rejected similar advice from another petitioner in Washington v. Watkins, 655 F.2d 1346, 1356-57 (5th Cir.1981), cert. denied, - U.S. —, —, 102 S.Ct. 2021, 72 L.Ed.2d 474 (1982), and we do so again here. The relevant inquiry in all cases involving claims of ineffectiveness of counsel, irrespective of the degree of punishment that the state seeks to impose, is whether counsel rendered reasonably effective assistance given the totality of the circumstances. The degree of punishment is but one of the totality of circumstances. See also Gray v. Lucas, 677 F.2d 1086, 1092 (5th Cir.1982).
Washington also argues that Tunkey’s failure to investigate and present character evidence rendered the imposition of the death penalty unconstitutional under Lockett v. Ohio, 438 U.S. 586, 98 S.Ct. 2954, 57 L.Ed.2d 973 (1978). In Lockett the Supreme Court struck down a procedure which prevented the sentencer from considering aspects of the defendant’s character and record as nonstatutory mitigating factors. Id. at 604, 98 S.Ct. at 2964. As noted by the court in Washington v. Watkins, the Supreme Court cases on the death penalty deal with “procedural flaw[s] in the system of justice,” not with alleged flaws in the judgment of counsel. 655 F.2d at 1356. Therefore, Tun-key’s failure to investigate or present extensive *1251character evidence does not render the imposition of the death penalty unconstitutional.
. The allegations of the petitioner in Plant are somewhat confusing. The petitioner apparently alleged that his counsel was ineffective for failing to prepare an alibi defense and relying instead on a defense that conceded petitioner’s proximity to the crime but alleged nonpartici-pation. See also cases cited infra note 21.
. Since the focus of the analysis in this opinion is the extent of investigation appropriate before proceeding to trial, we do not specifically discuss the duty to investigate before advising a client to plead guilty. See, e.g., McMann v. Richardson, 397 U.S. 759, 90 S.Ct. 1441, 25 L.Ed.2d 763 (1970). We do, however, draw upon the reasoning of these cases for certain general principles. See infra note 21.
. See also Beavers v. Balkcom, 636 F.2d 114, 116 (5th Cir.1981); Davis v. Alabama, 596 F.2d 1214, 1218 (5th Cir.1979), vacated as moot, 446 U.S. 903, 100 S.Ct. 1827, 64 L.Ed.2d 256 (1980); Wood v. Zahradnick, 578 F.2d 980, 982 (4th Cir.1978); United States v. Moore, 554 F.2d 1086, 1092-93 (D.C.Cir.1976); Brennan v. Blankenship, 472 F.Supp. 149, 155-57 (W.D.Va. 1979), aff’d mem., 624 F.2d 1093 (4th Cir.1980). Cf. Michel v. Louisiana, 350 U.S. 91, 105, 76 S.Ct. 158, 166, 100 L.Ed. 83 (1955) (Douglas, J., dissenting) (where state procedure deprived counsel of opportunity to raise one dispositive issue, defendant was denied his constitutional rights).
. The scope of duty to conduct an investigation into defendant’s one line of defense may be affected, however, by factors such as the strength of the government’s case. See, e.g., United States v. Katz, 425 F.2d 928, 930 (2d Cir.1970). Also, strategy may play a role when counsel reasonably determines that interviewing a certain witness or obtaining a certain report may prove to be more harmful to the defendant’s case than it is helpful. See, e.g., Easter v. Estelle, 609 F.2d 756, 759 (5th Cir.1980) (strategic choice not to open the door to prior crime evidence excuses failure to interview certain witnesses).
. In this case, for instance, Tunkey testified to the effect that he saw two plausible lines of defense: one based upon emotional distress and the other based upon expressions of sincerity calculated to play upon the judge’s known inclination to view such expressions with favor. According to his testimony, he presented a limited version of the first line at the plea colloquy and a full version of the second line at the sentencing hearing.
. Apart from this reluctance to interfere with the adversary process, there are concrete and sensible reasons why courts will almost invariably defer to the fully informed strategic choice of counsel. No two attorneys will present an identical defense, even if they are equipped with perfect knowledge. Advocacy is the art of persuasion; it is not a science. A court in a habeas corpus proceeding, several stages removed from the heat of battle, is seldom able to determine whether the strategic choices made by counsel were the right ones. See United States v. Bosch, 584 F.2d 1113, 1121 (1st Cir. 1978). See also Wiley v. Sowders, 647 F.2d 642, 648 (6th Cir.), cert. denied, 454 U.S. 1091, 102 S.Ct. 656, 70 L.Ed.2d 630 (1981); United States v. Thomann, 609 F.2d 560, 566 (1st Cir.1979); United States v. Katz, 425 F.2d 928, 930-31 (2d Cir.1970).
. We assume here, without deciding, that conferring with one’s client and reviewing the state’s case constitute the bare minimum amount of investigation that counsel must conduct before he forms his trial strategy.
. Just as the case law contains apparently contradictory statements regarding trial strategy, see supra at 1251, so it contains differing statements regarding the legitimate role of assumptions in the course of representation. In Powell v. Alabama, 287 U.S. 45, 53 S.Ct. 55, 77 L.Ed. 158 (1932), two attorneys were appointed to represent the defendants on the morning of trial. The Court found that they were thereby denied assistance of counsel:
It is not enough to assume that counsel thus precipitated into the case thought there was no defense, and exercised their best judgment in proceeding to trial without preparation .... No attempt was made to investigate. No opportunity to do so was given.
Id. at 58, 53 S.Ct. at 60. See also United States v. Moore, 554 F.2d 1086, 1092-93 (D.C.Cir.1976) (footnote omitted) (counsel’s failure to interview witnesses because of their expected response “does not excuse the failure to find out; speculation cannot substitute for certainty”).
Clearly, an attorney cannot excuse his total failure to investigate simply because he assumes that there is no way to defend his client. However, when an attorney is in the process of choosing the lines of defense on which he will concentrate his investigative effort, he will often have to use his professional judgment to form assumptions regarding the prospects for success from a certain line of defense. See Gray v. Lucas, 677 F.2d 1086, 1093 & n. 4 (5th Cir.1982) (assumptions regarding the best evidence likely to be derived from interviewing certain character witnesses justified strategic choice not to pursue that investigation); Plant v. Wyrick, 636 F.2d 188, 189-90 (8th Cir.1980) (decision not to pursue a certain line of inquiry was arrived at by “an experienced criminal attorney exercising his professional judgment”). See also cases cited infra note 21.
. See, e.g., Jones v. Kemp, 678 F.2d 929, 931-32 (11th Cir.1982) (strategic choice to investigate line of defense based upon lack of possession excuses failure to investigate defense based upon absence of knowledge); Wilkerson v. United States, 591 F.2d 1046, 1047 (5th Cir.1979) (strategic choice to concentrate upon legal challenges where government’s evidence was overwhelming excuses failure to perform “fruitless legwork”); Gray v. Lucas, 677 F.2d 1086, 1093-94 (5th Cir.1982) (strategic choice to investigate psychiatric evidence at the expense of character evidence was justified by *1256reasonable assumptions regarding probabilities of success); Plant v. Wyrick, 636 F.2d 188, 189-90 (8th Cir.1980) (failure to interview certain witnesses was a matter of professional judgment where counsel pursued the only defense that offered a significant possibility of success); Gustave v. United States, 627 F.2d 901, 906 (9th Cir.1980) (strategic choice regarding proper allocation of time excuses failure to inquire into racial bias of jury during voir dire); Reynolds v. Mabry, 574 F.2d 978, 981 (8th Cir.1978) (strategic choice to rely upon insanity defense excuses failure to investigate defenses relating to circumstances of arrest); United States v. Ladley, 517 F.2d 1190, 1194 (9th Cir. 1975) (strategic choice not to pursue certain lines of investigation excused where counsel presented forceful defense); United States v. Hearst, 466 F.Supp. 1068, 1087 (N.D.Cal.1978) (failure to investigate effects of pretrial publicity excused by strategic choice to conduct trial in San Francisco), aff’d in part, vacated in part, 638 F.2d 1190, 1195-96 (9th Cir.1980) (failure by attorney to investigate substantially possibility that hallucinogens affected defendant’s behavior excused where on the basis of trial strategy “he devoted his energies to other aspects of [the] defense”), cert. denied, 451 U.S. 938, 101 S.Ct. 2018, 68 L.Ed.2d 325 (1981). Cf. McMann v. Richardson, 397 U.S. 759, 769-70, 90 S.Ct. 1441, 1448-49, 25 L.Ed.2d 763 (1970) (in advising client whether to plead guilty, counsel necessarily relies upon his “best judgment” of possible defenses and the strength of the state’s case); Bradbury v. Wainwright, 658 F.2d 1083, 1087-88 (5th Cir.1981) (failure to investigate fully insanity defense before advising client to plead guilty is not ineffective assistance where partial investigation led attorney to reasonable conclusion that the defense had little chance to succeed); Jackson v. Estelle, 548 F.2d 617, 618 (5th Cir.1977) (same conclusion); Benson v. United States, 552 F.2d 223, 225 (8tli Cir.) (failure to make independent investigation of facts before advising client to plead guilty is not ineffective assistance when the case against defendant was overwhelming), cert. denied, 434 U.S. 851, 98 S.Ct. 164, 54 L.Ed.2d 120 (1977).
. See, e.g., Young v. Zant, 677 F.2d 792, 798-800 (11th Cir. 1982); Kemp v. Leggett, 635 F.2d 453, 454-55 (5th Cir.1981); Brubaker v. Dickson, 310 F.2d 30, 38-39 (9th Cir.1962), cert. denied, 372 U.S. 978, 83 S.Ct. 1110, 10 L.Ed.2d 143 (1963).
. The determination whether strategic choices based upon a set of assumptions are reasonable is a question of fact for the district courts. We suggest only a few factors to inform that determination. First, the experience of the attorney is relevant. An attorney who has handled numerous cases in the criminal field will have formed a more accurate picture of which lines of defense are most likely to succeed. Compare Kemp v. Leggett, 635 F.2d 453, 454 (5th Cir.1981) (attorney with little previous experience fails to interview witnesses and adopts a *1257line of defense “not the most compatible with the facts”) with Washington v. Watkins, 655 F.2d 1346, 1364 & n. 36 (5th Cir.1981) (attorney who had observed the tactics of other lawyers in comparable cases reasonably chose not to investigate racial composition of jury venire). Second, when the line of defense actually pursued by counsel was inconsistent with the line that was not pursued, counsel’s strategic choice to investigate one rather than the other is more likely to be reasonable. When the lines of defense are consistent so that both could be presented at trial, there may be a less compelling reason not to have pursued both prior to trial. Compare Jones v. Kemp, 678 F.2d 929, 931-32 (11th Cir.1982) (strategic choice not to investigate one line of defense is acceptable when presentation of that line at trial would have contradicted defendant’s testimony) and Gray v. Lucas, 677 F.2d 1086, 1094 (5th Cir. 1982) (strategic choice not to investigate fully one line of defense justified when lawyers could reasonably determine that a jury would find it inconsistent with line actually presented at trial) with In re Saunders, 2 Cal.3d 1033, 88 Cal.Rptr. 633, 472 P.2d 921 (1970) (strategic choice not to investigate diminished capacity defense was unreasonable when that defense was stronger than and consistent with the defense actually pursued). Finally, the degree of possible prejudice that might foreseeably result from the strategic choice is a relevant factor. See Cooper v. Fitzharris, 586 F.2d 1325, 1330 n. 10 (9th Cir.1978) (en banc), cert. denied, 440 U.S. 974, 99 S.Ct. 1542, 59 L.Ed.2d 793 (1979). Thus, a choice that was “likely to result in prejudice which was foreseeably less severe than that resulting from the chosen course” might be more reasonable than the chosen course. Id.
The listed factors are neither exhaustive nor individually determinative in the reasonableness inquiry. Cf. Washington v. Watkins, 655 F.2d at 1364 & n. 36 (strategic choice not to investigate racial composition of grand jury venire was reasonable even though that line of defense was not inconsistent with line presented at trial).
. A finding by the district court as to whether a choice was strategic is a finding of fact that will be accepted by the court of appeals unless clearly erroneous. Beckham v. Wainwright, 639 F.2d 262, 265-66 (5th Cir.1981). See also Pullman-Standard v. Swint, 456 U.S. -, -, 102 S.Ct. 1781, 1789-91, 72 L.Ed.2d 66 (1982); United States v. Cruz, 581 F.2d 535, 540-41 (5th Cir.1978) (en banc).
. In Frady Justice O’Connor employed that test to determine whether the petitioner had established prejudice within the meaning of the “cause and prejudice” formulation of Wainwright v. Sykes, 433 U.S. 72, 87, 97 S.Ct. 2497, 2506, 53 L.Ed.2d 594 (1977). For reasons discussed infra, we decide that this formulation of the petitioner’s burden is an equitable allocation of the burden of proof between the petitioner and the state in cases of ineffective assistance of counsel.
. .There may be cases in which the ineffectiveness of counsel is so pervasive that a particularized inquiry into prejudice would be “unguided speculation.” See, e.g., United States v. Porterfield, 624 F.2d 122, 125 (10th Cir.1980). This is certainly not such a case.
. It is not difficult to imagine the absurd and unjust results of a rule of automatic reversal. In United States v. Winston, 613 F.2d 221 (9th Cir.1980), the court found that petitioner’s trial counsel was arguably ineffective because of his failure to obtain a psychiatric report. The petitioner had been acquitted, however, on the one count to which the report was relevant. The court found, therefore, that petitioner had not been prejudiced by counsel’s ineffectiveness, and refused to grant the writ. Id. at 223. Washington’s proposed rule would require granting the writ in that situation.
. See also McQueen v. Swenson, 498 F.2d 207, 219 (8th Cir.1974). Indeed, even when the state shares responsibility for interfering with the effectiveness of petitioner’s counsel or with the presentation of his case, the courts will often require an inquiry into whether prejudice resulted. See, e.g., United States v. Valenzuela-Bernal, 458 U.S. -, -, 102 S.Ct. 3440, 3449-50, 73 L.Ed.2d 1193 (1982); Hopper v. Evans, 456 U.S. -, - & n. *, 102 S.Ct. 2049, 2054 & n. *, 72 L.Ed.2d 367 (1982); United States v. Morrison, 449 U.S. 361, 364-66 & n. 2, 101 S.Ct. 665, 667-69 & n. 2, 66 L.Ed.2d 564 (1981).
.At least one judge has suggested that Chapman itself requires some showing of prejudice by the defendant before the burden of showing harmlessness beyond a reasonable doubt shifts to the state. See United States v. Decoster, 624 F.2d 196, 237 (D.C.Cir.1979) (en banc) (MacKinnon, J., concurring).
The Supreme Court has in some instances required a positive showing of prejudice by a defendant before it will grant relief for an alleged violation of a constitutional right. See, e.g., United States v. Valenzuela-Bernal, 458 U.S. -, -, 102 S.Ct. 3440, 3446, 73 L.Ed.2d 1193 (1982) (compulsory process clause); United States v. Agurs, 427 U.S. 97, 104, 96 S.Ct. 2392, 2397-98, 49 L.Ed.2d 342 (1976) (due process clause); see Coles v. Peyton, 389 F.2d 224, 230 (4th Cir.) (Craven, J., dissenting) (discussing Estes v. Texas, 381 U.S. 532, 85 S.Ct. 1628, 14 L.Ed.2d 543 (1965)), cert. denied, 393 U.S. 849, 89 S.Ct. 80, 21 L.Ed.2d 120 (1968). Cf. Chambers v. Maroney, 399 U.S. 42, 54, 90 S.Ct. 1975, 1982, 26 L.Ed.2d 419 (1970) (alleged violation of right to effective assistance of counsel denied where “the claim of prejudice ... was without substantial basis”).
.If this court were to offer a significantly more favorable procedural posture to claims of ineffective assistance than to other habeas claims, we would establish a perverse incentive to present alleged trial errors as ineffective assistance claims. This incentive would tend to' undermine the “cause and prejudice” requirement in Wainwright and Frady, see Tague, Federal Habeas Corpus and Ineffective Representation of Counsel: The Supreme Court Has Work To Do, 31 Stan.L.Rev. 1, 63-64 (1978); Strazzella, Ineffective Assistance of Counsel Claims: New Uses, New Problems, 19 Ariz.L. Rev. 443, 479 (1977), and encourage the filing . of frivolous ineffectiveness claims in an attempt to obtain enhanced procedural advantages. See Cooper v. Fitzharris, 586 F.2d 1325, 1329-30 (9th Cir.1978) (en banc), cert. denied, 440 U.S. 974, 99 S.Ct. 1542, 59 L.Ed.2d 793 (1979).
The case law has generally recognized a rough congruence between the showing of prejudice necessary to avoid procedural default under Wainwright and the showing of prejudice necessary to obtain a new trial for ineffective assistance of counsel. See, e.g., Jurek v. Estelle, 593 F.2d 672, 680-84 (5th Cir.), vacated, 597 F.2d 590 (5th Cir.1979), rehearing en banc, 623 F.2d 929 (5th Cir. 1980) (issue of interplay between Wainwright and substantive prejudice requirement not reached), cert. denied, 450 U.S. 1001, 101 S.Ct. 1709, 68 L.Ed.2d 203 (1981); Canary v. Bland, 583 F.2d 887, 890 (6th Cir.1978). See also Wainwright v. Sykes, 433 U.S. 72, 98, 97 S.Ct. 2497, 2512, 53 L.Ed.2d 594 (1977) (White, J., concurring).
. If in a given case the petitioner does not have access to the information necessary to sustain his burden of proof, the district court is of course free to make appropriate adjustments in the allocation of the burden. See, e.g., United States ex rel. Green v. Rundle, 434 F.2d 1112, 1115 (3d Cir.1970).
. See supra note 25 regarding the general congruence between the showing of prejudice to avoid procedural default and the showing necessary to obtain a new trial for violation of the right to effective assistance of counsel. See also The Supreme Court, 1976 Term, 91 Harv.L. Rev. 70, 219-21 (1977).
. Our acceptance of the rule that the ineffective counsel question and the prejudice question are distinct inquiries, Washington v. Watkins, 655 F.2d at 1359 n. 23, may seem to imply that there is a bright line between the two. We recognize, however, that such is not always the case. Claimed errors of omission or commission arise in a wide variety of circumstances sometimes resulting in substantial imbrication.
On occasion it may be perfectly clear that an omitted act or a potential line of inquiry would not have benefited the defendant. The evinced absence of prejudice then mitigates the need for inquiry into the effectiveness of counsel. (Indeed, manifest absence of benefit to defendant may have been the reason for its abandonment' by effective counsel). We do not suggest that when it is apparent that no prejudice resulted from a claimed act or omission, and a habeas court so finds, that it commits reversible error by failing to record specific findings with respect to the effectiveness inquiry. We also do not suggest that under all circumstances the stated order of consideration of the two issues will be the more orderly or logical.
As we have determined above, however, constitutional deprivation of the assistance of counsel is not shown until prejudice also is shown, when as here the claimed ineffectiveness consists of counsel’s errors of omission or commission.
In addition to being analytically sound, separate and distinct findings on the two issues provide a practical advantage during the apparently inevitable appeal. In many cases they may avoid the necessity of a remand for further findings.
. As noted above, the petitioner raised fourteen legal challenges to the death sentence in addition to his ineffectiveness claim. We have already affirmed the district court’s disposition of one of those claims. See supra note 7. The remaining thirteen challenges were dismissed by the district court without elaboration because, in its view, “independent review of these issues reveals them to be meritless.”
The panel opinion correctly stated that it is the preferred practice for the district court to include a brief explanation of its disposition of each individual claim. This practice is not mandatory, however, when the court “reject[s] claims which it regards as frivolous or totally without merit.” Sumner v. Mata, 449 U.S. 539, 548, 101 S.Ct. 764, 770, 66 L.Ed.2d 722 (1981). The district court found the remaining thirteen grounds to be devoid of merit, and our review of those grounds persuades us that the district court could appropriately reject those grounds without elaboration. We therefore affirm the dismissal of the remaining thirteen grounds.
Additionally, the state cross-appealed the district court’s refusal to dismiss Washington’s petition as untimely and therefore as an abuse of the writ. We affirm the district court’s decision. See Jackson v. Estelle, 570 F.2d 546, 547 (5th Cir.1978).