The high court concluded that the petitioner, who was claiming he had been prejudiced by ineffective assistance of counsel, had not met the standard under 28 U.S.C. sec. 2254(d) (AEDPA), which requires the state decision be contrary to clearly established federal law. The California Supreme Court had assumed ineffective assistance, but found no prejudice at sentencing in this death penalty case. The high court criticized the Ninth Circuit’s opinion granting relief, concluding its opinion was erroneous in failing to use the modifier “reasonably” when concluding it was “probable” that a result more favorable would have occurred absent the constitutional error. Also, the Ninth Circuit failed to observe the required distinction under federal habeas law between an “unreasonable” application of federal law and an “incorrect” application of federal law. Only the former warrant relief.