What is the effect of the closing argument of defense counsel at trial for a second-degree murder?

On direct appeal, petitioner argued that the closing argument of defense counsel violated his right to effective assistance of counsel for abandoning his claim of innocence and conceding guilt on second degree murder, along with a related claim not relevant here. On April 13, 2012, we rejected this argument because the concession was tactically justifiable, relying on People v. Gamache (2010) 48 Cal.4th 347, 392-393, 106 Cal.Rptr.3d 771, 227 P.3d 342, and its progeny. Petitioner did not file a petition for review, so that judgment became final. Petitioner filed multiple post-conviction collateral attacks on the judgment arguing he was deprived of effective assistance of counsel when his attorney argued to the jury that it should convict him of second degree murder, not first, but each was denied in turn.