I am hoping that Rodger Federer will finish his career this year , I think it will be the first time that a player do that when he is number one , in the top of the world , for his legacy and for history I hope that he will do it this year , without no doubt he is the goat " greatest of all times" and I hope that we keep only the memory of him when he was on the top .
I would like to see him play way longer. As long as he can perform on high level. Hovever the years are mounting up and I wouldn't be surprised if he decides to take a further cut in tournament number and decides to play just few of his favorite tournaments. Doesn't matter which ranking he has when he decides to stop. He will be the greatest anyway.
Imagine the situation with Federer let's say at 40 years deciding to play only half of master 1000 and GS tournaments and wining half of them. It would add to the legend even if he is not no. 1 any more.