with whom LEVIN H. CAMPBELL, Circuit Judge, joins (dissenting).
Although I freely concede that the issue is debatable, I must respectfully dissent from the decision of the en banc court. I remain of the opinion that, in the interval between our decision in United States v. Rivera-Sola, 713 F.2d 866 (1st Cir.1983) and the Court’s decision in United States v. Gomez, — U.S. -, 109 S.Ct. 2237, 104 L.Ed.2d 923 (1989), a preserved objection was a prerequisite to a successful appeal based on a magistrate’s jury empanelment. In this case, there was no such preserved objection and no issue of fairness or justice necessitates that the defendants’ convictions be vacated. Gomez, by its terms, does not demand so arbitrary a result. Thus, the defendants’ convictions should stand.
I am mindful that the Supreme Court, apparently intent upon resolving the split in the circuits, has lately taken certiorari in United States v. France, 886 F.2d 223 (9th *1557Cir.1989), cert. granted, — U.S. -, 110 S.Ct. 1921, 109 L.Ed.2d 285 (1990). Rather than reinvent the wheel, therefore, I simply reiterate, in slightly edited form, what we wrote in the original panel opinion, 890 F.2d 490, now withdrawn.
In Gomez, the defendants preserved their rights, and the Court was careful to limit its holding accordingly. See, e.g., Gomez, 109 S.Ct. at 2239 (describing “question presented” as “whether presiding at the selection of a jury in a felony trial without the defendant’s consent” is a proper office of a magistrate) (emphasis supplied). In the case before us, defendants did not object to the empanelment, and we must determine the effect of this failure. As the majority recognizes, see ante at 1555-56, the circuits which have addressed similar questions in Gomez’s, aftermath have reached different conclusions, sometimes by very different routes.
I
Ordinarily, the law ministers to the vigilant, not to those who sleep upon their rights. In consequence, a litigant, through counsel, must usually stake out his opposition to a trial court’s ruling on pain of forfeiting any right subsequently to complain. There are sound policy reasons behind the raise-or-waive rule: calling an incipient error to the judge’s attention alerts both the court and opposing counsel, affording an opportunity to correct the problem before harm is done; it also prevents litigants from having their cake and eating it too, say, by making a strategic judgment and later, when the result proves infelicitous, assigning error.
Notwithstanding the strength and salience of these policies, there are exceptions to the raise-or-waive rule. One such exception is for “plain error”. Fed.R.Crim.P. 52(b). The rubric has been much defined, mostly by way of uncontroversial generalities. Plain errors are those that “seriously affect the fairness, integrity or public reputation of judicial proceedings,” United States v. Atkinson, 297 U.S. 157, 160, 56 S.Ct. 391, 392, 80 L.Ed. 555 (1936); or those of such magnitude that “the trial judge and prosecutor were derelict in countenancing” them, United States v. Frady, 456 U.S. 152, 163, 102 S.Ct. 1584, 1592, 71 L.Ed.2d 816 (1982); or those that “undermine the fundamental fairness of the trial,” United States v. Young, 470 U.S. 1, 16, 105 S.Ct. 1038, 1046, 84 L.Ed.2d 1 (1985). We, ourselves, have described plain errors as “those errors so shocking that they seriously affect the fundamental fairness and basic integrity of the proceedings conducted below.” United States v. Griffin, 818 F.2d 97, 100 (1st Cir.), cert. denied, 484 U.S. 844, 108 S.Ct. 137, 98 L.Ed.2d 94 (1987). Courts seem agreed that the doctrine is to be used “sparingly,” Frady, 456 U.S. at 163 n. 14, 102 S.Ct. at 1592 n. 14; Smith v. Massachusetts Inst. of Technology, 877 F.2d 1106, 1110 (1st Cir.1989), and then only where the error likely had an “unfair prejudicial impact on the jury’s deliberations.” Young, 470 U.S. at 16 n. 14, 105 S.Ct. at 1047 n. 14.6 In a nutshell, relief on “plain error” grounds is reserved for “those circumstances in which a miscarriage of justice would otherwise result.” Frady, 456 U.S. at 163 n. 14, 102 S.Ct. at 1592 n. 14; accord Griffin, 818 F.2d at 100; Nimrod v. Sylvester, 369 F.2d 870, 873 (1st Cir.1966).
II
A
Although the idiom of plain error is familiar, its application, as in this case, is *1558often beset with uncertainty.7 To be sure, as the majority recounts, we earlier concluded that a criminal defendant who failed to object to a magistrate’s jury empanelment “waived his right to object,” the same not amounting to plain error. Rivera-Sola, 713 F.2d at 872, 874. See also United States v. Ford, 824 F.2d 1430, 1434-39 (5th Cir.1987) (en banc) (holding practice to be impermissible, but affirming conviction because defendant “did not object and ... trial was fundamentally fair”), cert. denied, 484 U.S. 1034, 108 S.Ct. 741, 98 L.Ed.2d 776 (1988). Nevertheless, the Gomez Court’s holding that the Federal Magistrates Act does not allow delegation of jury selection to magistrates in felony cases, 109 S.Ct. at 2240-47, alters the calculus of plain error, if not necessarily the result.
In hindsight, given Gomez, the error below now appears obvious. But as explained above, plain error requires more than retrospective obviousness; unless the error rendered the trial fundamentally unfair, or overlooking it would shock the conscience, then the error is not “plain.”
Appellants' argument for plain error, as we understand it, has four prongs.8 This court, which pegs its ruling on “an unexcused violation of a fundamental provision of the [Federal Magistrates Act],” ante at 1556, synthesizes the four prongs. Reliance on this rather strange amalgam, which my brethren concede is “quite apart from plain error in conventional terms,” id., requires me to examine each prong.
First, appellants suggest (though the majority, to its credit, seemingly disagrees) that Gomez, which ruled harmless-error jurisprudence inapplicable to empanelment by a magistrate, 109 S.Ct. at 2247-48, has preempted our determination. Stating that “harmless-error analysis does not apply in a felony case in which, despite the defendant’s objection ... an officer exceeds his jurisdiction by selecting a jury,” id. at 2248, however, is to say nothing — or next to nothing — about plain error.
Simply put, visualizing plain error and harmless error as flip sides of the same coin is wrong. See United States v. Acevedo, 842 F.2d 502, 508 n. 3 (1st Cir.1988); United States v. Silverstein, 732 F.2d 1338, 1349 (7th Cir.1984), cert. denied, 469 U.S. 1111, 105 S.Ct. 792, 83 L.Ed.2d 785 (1985); United States v. Blackwell, 694 F.2d 1325, 1340-41 (D.C.Cir.1982); 3A C. Wright, Federal Practice and Procedure: Criminal 2d §§ 851, 856 (1982). The difference in dimension between plain error and reversible error may frequently be small— but it is real. And, the policies which drive the two concepts are largely dissimilar. I agree with the Seventh Circuit that, unlike harmless-error analysis (which focuses on the prejudicial nature vel non of a preserved objection, and thus, seeks to give a diligent defendant his due), excusing a litigant’s outright neglect is considerably more disruptive of our system of justice:
Reversing a conviction on the basis of an error that the defendant’s lawyer failed to bring to the judge’s attention is inconsistent with the premises of an adversary system and disruptive of the efficient operation of the criminal justice system. It is justifiable only when the reviewing court is convinced that it is necessary in order to avert an actual miscarriage of justice, which implies the conviction of one who but for the error probably would have been acquitted.
*1559Silverstein, 732 F.2d at 1349; accord Griffin, 818 F.2d at 100 (plain error different from “prejudicial” error); McMillen v. United States, 386 F.2d 29, 35 (1st Cir.1967) (same), cert. denied, 390 U.S. 1031, 88 S.Ct. 1424, 20 L.Ed.2d 288 (1968).
The next prong is a branch of the first. The majority, ante at 1555, quotes liberally from Gomez to indicate the importance of jury selection and the “basic” nature of “a defendant’s right to have all critical stages of a criminal trial conducted by a person with jurisdiction to preside.” Gomez, 109 S.Ct. at 2248. Yet, as the Second Circuit has recognized, see United States v. Wong, 884 F.2d 1537, 1545 (2d Cir.1989), cert. denied, — U.S. -, 110 S.Ct. 1140, 107 L.Ed.2d 1045 (1990), the Gomez Court’s concern was with whether the error — to which objection had been preserved — could ever be considered harmless beyond a reasonable doubt. See, e.g., Chapman v. California, 386 U.S. 18, 23-24, 87 S.Ct. 824, 827-28, 17 L.Ed.2d 705 (1967); Fahy v. Connecticut, 375 U.S. 85, 86-87, 84 S.Ct. 229, 230-31, 11 L.Ed.2d 171 (1963). Thus, the language in question, read in context, signals only the Court’s perception that there would always be “a reasonable possibility that the [error] complained of might have contributed to the conviction.” See Fahy, 375 U.S. at 86-87, 84 S.Ct. at 230-31. Be that as it may, an error, to be “un-plain,” need not be harmless beyond all reasonable doubt. More is needed to breach the sturdy fortifications surrounding the raise-or-waive rule.
In effect, the second prong on which reversal rests is tantamount to a declaration that the right to have an Article III judge preside at empanelment is so essential to the fairness of a felony trial that it cannot be waived. But, that dog will not hunt. This, perhaps, is the crux of the matter; unlike the majority, I see no a priori connection between the presiding of a magistrate over voir dire — even a statutorily unauthorized presiding — and fundamental unfairness to a defendant. Nothing inherent in the position, appointment, training, or function of magistrates necessitates a categorical conclusion that their participation renders empanelment proceedings grossly unjust. Indeed, if any categorical assumption were to be made, I would feel more inclined to assume the exact opposite: the neutral, detached, and experienced perspective of magistrates bolsters the inference that proceedings conducted under their auspices, even outside the scope of their legal jurisdiction, are likely fair.
More importantly, even if it may be presumed that depriving a defendant of the right to have an Article III judge preside over voir dire entails some unfairness to the defendant, the deprivation is relatively innocuous. Time and again, courts have upheld waivers of rights equivalent to, or more basic than, this one.9 See, e.g., United States v. Figueroa, 818 F.2d 1020, 1025 (1st Cir.1987) (lack of timely objection foreclosed apprehended defendant’s argument that he was not brought before magistrate without unnecessary delay); United States v. Bayko, 774 F.2d 516, 517 (1st Cir.1985) (ex post facto defense pretermitted by failure to raise); United States v. Bascaro, 742 F.2d 1335, 1365 (11th Cir.1984) (failure to object at second trial waives double jeopardy defense), cert. denied, 472 U.S. 1017, 105 S.Ct. 3476, 87 L.Ed.2d 613, 472 U.S. 1021, 105 S.Ct. 3488, 87 L.Ed.2d 622 (1985); United States v. Coleman, 707 F.2d 374, 376 (9th Cir.) (fifth amendment claim waived if not raised at trial), cert. denied, 464 U.S. 854, 104 S.Ct. 171, 78 L.Ed.2d 154 (1983); Paul v. Henderson, 698 F.2d 589, 592 (2d Cir.) (same as Bascaro; collecting cases), cert. denied, 464 U.S. 835, 104 S.Ct. 120, 78 L.Ed.2d 118 (1983); United States v. Surridge, 687 F.2d 250, 255 (8th Cir.) (fourth amendment objection waived if not seasonably raised), cert. denied, 459 U.S. 1044, 103 S.Ct. 465, 74 L.Ed.2d 614 (1982); United States v. Goodwin, 612 F.2d 1103, 1105 (8th Cir.) (sixth amendment claim not surfaced at trial should not be considered on appeal), cert. denied, 446 U.S. 986, 100 S.Ct. 2971, 64 L.Ed.2d 844 (1980).
*1560The third prong intimates the existence of some unfairness in this particular em-panelment. The majority gives this no credence. Nor do I. Magistrate Castellanos fully protected defendants’ legitimate rights. The judge was available and, when defendants pressed an objection before the magistrate, the judge resolved the question. The magistrate’s preliminary comments to the jury were standard and defendants voiced no objection (then or now) to any portion of what was said. Questions were addressed to the venire from a prepared form. Once the jury was chosen, the judge — not the magistrate — gave the start-of-trial instructions. From aught that appears, the empanelment was scrupulously fair and the jury unbesmirched. -
I come last to the fourth prong: what I term the court’s discretion. See, e.g., Reilly v. United States, 863 F.2d 149, 161 (1st Cir.1988); United States v. Krynicki, 689 F.2d 289, 291 (1st Cir.1982). The pivotal inquiry here is whether counsel can be excused for not having raised the point below (thus affording the trial court the opportunity to make the correction itself, avoiding wasted effort). Griffin, 818 F.2d at 99-100. The majority argues that this court had already approved the practice in Rivera-Sola, so that objecting would have been like shouting into a gale-force wind. A contrary view, they say, “favors only obnoxiously belligerent counsel.” Ante at 1554. I am not persuaded.
In Rivera-Sola, we held that jury em-panelment by a magistrate was not plain error. 713 F.2d at 874. Other comments, although generally approving of the practice, were obvious dicta. No reported case in this circuit (or any other circuit, save the Ninth) had, before this jury was chosen, sanctioned the practice in the face of a contemporaneous, preserved objection. Put another way, in this circuit, unlike in the Ninth, there was no “ ‘solid wall of circuit authority’ which would have prevented the district court from correcting the alleged error.” See France, 886 F.2d at 228 (quoting Guam v. Yang, 850 F.2d 507, 512 n. 8 (9th Cir.1988) (en banc)). I strongly believe, therefore, that the justification for the “solid wall” exception does not pertain in the case at bar.
The exception’s genesis, as France explained, is that “[ojbjeeting in the trial court to a clearly defined rule of the circuit is futile, inasmuch as the trial court cannot overrule authority binding on it.” Id.; accord Martone v. United States, 435 F.2d 609, 610-11 (1st Cir.1970). There was no binding rule in this circuit such as necessarily foredoomed an objection to magistrates’ empaneling. A single case, the holding of which was dependent on the defendant’s failure to object, is hardly a “solid wall.” This is particularly true of a matter like utilization óf a magistrate. Even in circuits where courts of appeals had authorized the practice of having magistrates preside at empanelment, no court of appeals had insisted that the practice be followed. The district judge always retained discretion to preside over jury selection. In that sense, then, district courts were never duty-bound in the punctilious observance of circuit precedent to overrule an objection to the magistrate’s participation.
What little anecdotal evidence can be found suggests that, in the interval between Rivera-Sola and Gomez, district courts were willing to listen if a felony defendant pressed an objection to having a magistrate preside at empanelment. See, e.g., United States v. Kelley, No. 84-0029 (D.R.I. May 30, 1984) (upon defendant’s objection, magistrate stands down and district judge empanels in felony tax prosecution). Because the precedential wall in this instance was more porous than the majority will acknowledge, there was no valid reason for defense counsel to feel certain that timely objection to the magistrate's involvement would be futile.10 For that reason, and because there is not the slightest hint that the empanelment was actually *1561unfair, the jury tainted, or the verdicts affected, I think it wrong to exercise discretion to relieve the defendants from the natural consequences of their procedural default.
Ill
In Gomez, the Court took pains not to foreclose a plain error inquiry. That inquiry, conducted without a thumb on the scales, fortifies the conclusion that the raise-or-waive rule should be allowed to operate. Neither the integrity of the trial process nor the accuracy of the jury verdicts has been impeached. There is simply no reason to believe that the magistrate — a neutral and detached judicial officer, albeit not statutorily authorized to preside— stacked the deck against defendants; that the jury selected was other than impartial and representative; or that the verdicts were influenced by the fact that the district judge did not directly oversee empanelment.
In my estimation, these defendants were scrupulously tried and justly convicted. Because the error they belatedly assign was not preserved and cannot be said to have “seriously affect[ed] the fairness, integrity or public reputation” of the trial, Atkinson, 297 U.S. at 160, 56 S.Ct. at 392, their convictions should not be vacated.
. Following the Court's lead, we have often indicated that the probability of a changed outcome, or more, is a condition precedent to overlooking the lack of a contemporaneous objection. See, e.g., United States v. Williams, 809 F.2d 75, 82 (1st Cir.1986) (plain error would be one which "virtually ... insure[d]” a different outcome), cert. denied, 481 U.S. 1030, 107 S.Ct. 1959, 95 L.Ed.2d 531, 481 U.S. 1072, 107 S.Ct. 2469, 95 L.Ed.2d 877, 482 U.S. 906, 107 S.Ct. 2484, 96 L.Ed.2d 377 (1987); United States v. West, 723 F.2d 1, 2 n. 1 (1st Cir.1983) (same), cert. denied, 469 U.S. 1188, 105 S.Ct. 956, 83 L.Ed.2d 963 *1558(1985). The requirement may not be inflexible, but it is of general application.
. Professor Wright wryly observed that the cases left him with the impression that appellate courts have not put much flesh on plain error’s definitional bones, "save that they know it when they see it.” 3A C. Wright, Federal Practice and Procedure: Criminal 2d § 586 (1982), at 337.
. As to a possible fifth prong, it cannot seriously be contended that the magistrate lacked jurisdiction in the sense that the district court lost, or was deprived of, subject matter jurisdiction, thus eclipsing the raise-or-waive rule. See, e.g., Louisville & Nashville R. Co. v. Mottley, 211 U.S. 149, 152, 29 S.Ct. 42, 43, 53 L.Ed. 126 (1908); Capron v. Van Noorden, 6 U.S. 126, 127, 2 Cranch 126, 127, 2 L.Ed. 229 (1804). The district court possessed subject matter jurisdiction throughout, although the magistrate lacked statutory authority to exercise that jurisdiction. The resultant irregularity was procedural, not jurisdictional. See Archie v. Christian, 808 F.2d 1132, 1134-35 (5th Cir.1987) (en banc).
. We have already ruled that errors infringing on the right to an impartial jury, even if not harmless, need not necessarily be deemed plain. See Acevedo, 842 F.2d at 508 & n. 3.
. Defense counsel in Gomez, confronted with a Second Circuit precedent which was a fair con-gener to Rivera-Sola, United States v. DeFiore, 720 F.2d 757, 764-65 (2d Cir.1983), cert. denied, 466 U.S. 906, 104 S.Ct. 1684, 80 L.Ed.2d 158 (1984), saw fit to preserve this very sort of objection.