Following a non-jury trial, appellant was convicted of possessing an instrument of crime,1 robbery,2 and aggravated assault.3 Post-trial motions for a new trial and in arrest of judgment were denied, and sentence was imposed. For the reasons stated herein, we vacate the judgment of sentence and remand to the court of common pleas.
The pertinent facts are as follows. On November 1, 1976, the complainant, Mr. Homer Auston, and Mr. George Black-*123man were engaged in a game of shuffleboard in a local Philadelphia bar. They wagered on the contest and exchanged money at the end of each game. After the contest concluded, appellant, who had observed the match, asked complainant to loan him five dollars, which request was refused. Subsequently, appellant asked the complainant to accompany him to a rear portion of the establishment to discuss the matter further. The complainant complied and, accompanied by Mr. Blackman and another bar patron, Doug Cannon, followed appellant into a back room. There appellant produced a gun, ordered Messrs. Blackman and Cannon into a corner, and then demanded money from the complainant. After removing money from the complainant’s pocket, appellant ordered all three men to proceed onto the street fronting the establishment. Once outside the bar, the complainant overheard appellant telling Mr. Cannon that he was going to let Mr. Blackman go and was going to “cap” (i. e. kill) the complainant. The complainant then fled the scene and was pursued by appellant who, complainant testified, fired a shot at him during the chase.
The complainant eventually escaped and was able to locate Officer Edward Maenner of the Philadelphia Police Department and relate his account to him. Because he was familiar with appellant and was aware that there was an outstanding warrant for his arrest, Officer Maenner proceeded to a bar that he knew appellant frequented. There he confronted appellant and, after a short chase, arrested him.
On appeal, appellant contends that he was denied effective assistance of counsel due to counsel’s failure to interview or subpoena Mr. Cannon, an acquitted co-defendant to the crime, and for counsel’s failure either to interview Mr. Blackman prior to calling him as a defense witness, or to claim surprise when he testified adversely to appellant’s interest.
In Commonwealth v. Wade, 480 Pa. 160, 389 A.2d 560 (1978), our supreme court stated that:
*124“[B]efore a defendant on direct appeal is entitled to relief under a theory of ineffective assistance of trial counsel, it must appear that the lawyer’s act of omission or commission was arguably ineffective representation, and that it is likely that such ineffectiveness was prejudicial to the defendant. To resolve these matters it is frequently necessary for an appellate court to remand to the trial court for an evidentiary hearing.” Id., 480 Pa. at 172-73, 389 A.2d at 566 (emphasis added).
See also Commonwealth v. Hubbard, 472 Pa. 259, 372 A.2d 687 (1977); Commonwealth v. Twiggs, 460 Pa. 105, 331 A.2d 440 (1975). The instant case presents a situation wherein an evidentiary hearing is essential.
The dissent concludes that “[i]t is impossible to see how the testimony of Blackman had any reasonable basis to effectuate his client’s interest in the instant case. By no standard of reasonableness could such trial conduct be excused. No trial strategy for the defense appears.” (Dissenting opinion at 461). Yet, the dissent reaches this conclusion without the benefit of a record developed in the trial court. Although it is hard to conceive of a reasonable basis for calling Mr. Blackman as a defense witness, guesswork and speculation are no substitute for a record. There has been no opportunity for counsel to explain his trial strategy. Because our review of the record yields no definite conclusion regarding the effectiveness of counsel’s assistance, we must remand the case for an evidentiary hearing.
Accordingly, the judgment of sentence is vacated and the case is remanded to the trial court for an evidentiary hearing on the issue of counsel’s assistance at trial. Should the trial court conclude that counsel was ineffective, then a new trial shall be granted; if counsel is deemed to have been effective, the judgment of sentence shall be reinstated.
WATKINS, J., files a dissenting opinion. JACOBS, former President Judge, did not participate in the consideration or decision of this case.. 18 Pa. C.S. § 907.
. 18 Pa. C.S. § 3701.
. 18 Pa. C.S. § 2702.