It is said that when he lost the game, he sometimes break the racket.
But, he is well known as a very gentlemanly person now.
What changed his character?
It is said that this is tennis
the result of his game and the number of times of getting angry while he plays game are in inverse proportion. so he came to control his feeling.
Reference
wikipedia http://en.wikipedia.org/wiki/Roger_Federer
(2014 6 1 access)
jockbio http://www.jockbio.com/Bios/Federer/Federer_bio.html
(2014 6 1 access)
http://www.jockbio.com/Bios/Federer/Federer_bio.html
・Highest ranking No,1 in 2 february 2004.