Roger Federer is resigning from proficient tennis at age 41 after a progression of knee tasks
Federer closing a career in which he won 20 Grand Slam titles, finished five seasons ranked No. 1
"I am 41 years old. I have played more than 1500 matches over 24 years.
Federer's 20 Grand Slam titles rank third all-time among men's players
Federer, Nadal, Djokovic and Andy Murray are set to play together for the first time when they compete Sept. 23-25
Federer's records include being the oldest No. 1 in ATP rankings history
Federer leaves with 103 tour-level titles on his substantial résumé and 1,251 wins in singles matches
Federer won his first Grand Slam title at Wimbledon in 2003,
Federer would go on to blow w
ay past that, ending up
with 20 by winning eight championships at Wimbledon
Federer and his wife, Mirka a tennis player too; they met as athletes at an Olympics -- have two sets of twins.