What is the test for determining whether a defendant would have been more likely than not to have received a different verdict with the evidence?

"The question is not whether the defendant would more likely than not have received a different verdict with the evidence, but whether in its absence he received a fair trial, understood as a trial resulting in a verdict worthy of confidence. A 'reasonable probability' of a different result is accordingly shown when the government's evidentiary suppression 'undermines confidence in the outcome of the trial.' [Citation.]" (Kyles v. Whitley (1995) 514 U.S. 419, 434.) To put it another way, the question is whether "the favorable evidence could reasonably be taken to put the whole case in such a different light as to undermine confidence in the verdict." (Id. at p. 435, fn. omitted.)