This is actually a much more complicated and deeper question than most people are giving it credit for being, especially at the top championship levels. Go beneath the surface, think.
A couple of examples to ponder: Ivan Lendl, the great tennis player of the seventies and eighties, was never out of the game. His entire demeanor of toughness and intimidation was center stage all the time, he was never out of character. If you were at the net as his opponent he would try and "nail" you with a 100+ mph shot to your chest, or maybe your head. Asked a rival if he gave his opponent a point, the response was "Are you kidding?, 10 plus years on the pro circuit with him and he never gave you a "hello".
Jimmy Conners is another example, on the Johnny Carson show years ago he was talking tennis with Johnny who asked if he had a court at his house, the answer "yes", then whether Jimmy's young son liked playing and whether they played together often, answer "yes", next question was whether he let the kid win a few games, answer "NO". The competitiveness was never allowed to recede...never. Harsh examples, of course, but it's a really complicated question with an individual answer originating from whom you ask and what they are trying to accomplish.
J