Age and experience have been key this year in SW19.
The American beat hometown favorite Andy Murray in a Wimbledon quarterfinal on Wednesday.
The commentator is steeped in more controversy.
Research shows top players grunted at a higher pitch in matches they lost.
McEnroe has already been in trouble for comments he made this summer.
The big four have dominated the men's singles game at SW19.
Murray begins his defense on Monday in London.
The SW19 champion shared a joint with The Rolling Stones' frontman.
British players are given priority even if they are not particularly good.
Djokovic faces Dominic Thiem in the quarterfinal at Roland Garros.
The Russian returned from a doping ban in April.