I hate to ruin this giant Fedtard orgy (I really do), but Federer isn't close to being the best number one of all time.
Before computer rankings, it was impossible to know how many weeks a tennis player held the World No. 1 status. The only given were the Year-End rankings, but the number of tournaments was simply not the same in the The Golden Age of Tennis inside the Pro Era. Even the 70s rankings are a little stretched as to the number of consecutive weeks with a No.1 position. The computer rankings were run only a few times a year, unlike today.