Also, there are many other factors that can influence an athlete besides coaching in terms of how he plays the game and manages his career. This could also be said to be a fallacy of composition, whereby attributes of parts of the 'whole' (one aspect of Sampras' life) is used to make a generalization about the whole itself (in this case, Sampras' entire career). There is also the hasty generalization of assuming that excelling on different surfaces equals overall excellence in a wide variety of environments. Finally another hasty generalization is that there are other ways of measuring 'greatness' in the sport, including the cultural impact and the even...

It is also difficult to compare players from one era of tennis to another. Therefore, the argument also shows a failure of ambiguity.
Final argument:

P1: Roger Federer was extremely influenced by the legacy of Pete Sampras and tried to accomplish things even Sampras did not.

P2: Roger Federer won 17 Grand Slams, more than any other male singles player.

P3: Roger Federer has won Grand Slams on all three major surfaces which Sampras did not do.

Therefore, Roger Federer accomplished his goal of exceeding the achievements of Sampras.