I think very often, such obsessing over the details of our failures is just wishful thinking. We are trying to rationalize our failure. Rationalizing is much ea

I think very often, such obsessing over the details of our failures is just wishful thinking. We are trying to rationalize our failure. Rationalizing is much easier if you distill the causes of failure to one simple event. In this specific case, that modification of strategy would have saved the set, perhaps, and given him a chance to continue fighting in the match. A win would be far from guaranteed, counterfactuals are hard to construct and almost always impossible to verify. Tennis is a sport where you will rue every single point in a lost match. It lends itself particularly well to the if-only-I-did-that-one-thing-differently rationalization. It is due to the hierarchical (game-set-match) nature of the scoring and how one only needs to win one crucial point to get past their competitor (e.g. at 30-30, 30-15, the players are really sitting on a knife's edge).