He is the closer for the Yankees and has been so since 1997. Last night he established a new mark for all-time regular season saves. When he retires who knows what the number will be.
He has done this with basically one pitch "the cutter", so the hitters know whats coming, and have known it for 15 seasons but very few have had much success dealing with it.
However it is in the post season that his record really marks him out as stellar. He has recorded 42 saves (preserves the win when the lead is 4 runs or less) in post-season play, the next 3 on the list have 18,15 and 11.
In addition he happens to be a genuinely humble man.