abmk
Bionic Poster
I have a very simplistic view that the "mental aspect" plays a major role in Sports and performance in general. This is why Djokovic himself admitted that he got Becker as a coach because he felt to overtake both Fed and Nadal, he needed that extra mental toughness. Nadal had won his last 3 BO5 matches (HC, Grass, Clay) coming into that Final against Fed and had won 6 out of the last 7 against Fed. After Fed lost the 2nd set in that 2010 ATP FInal he now must think, "Now I need to win 2 more sets against the guy who beat me 6 out of the last 7. We'll never know what would've happened if it was Bo5 instead of Bo3. Unfortunately, the same can be said about many other tournaments that were watered down from Bo5 to Bo3.
Federer is most comfortable mentally vs Nadal indoors. Game just works better. Bo5 actually reduces Nadal's chances further.