What is the test for ineffective counsel in a habeas corpus case?

"A habeas corpus petitioner is entitled to an evidentiary hearing if he has alleged facts which, if proven, would entitle him to relief and he did not receive a full and fair evidentiary hearing in a state court." Id. A successful claim of ineffective assistance of counsel requires a showing both that counsel's performance was deficient and that this deficient performance prejudiced the defense. See Strickland v. Washington, 466 U.S. 668, 687 (1984). We must determine "whether, in light of all the circumstances, the identified acts or omissions were outside the wide range of professionally competent assistance." Id. at 690.