I just found a chilling y.e.c stat for Freddy.
17 appearances 16 Semi-Finals!
Only on ONE occasion did Freddy not make it out of the Round-Robin stage (sheesh!)
He's only 1 ahead of the rest here in y.e.c crowns, but his Tie-Breaker y.e.c stats just blow the rest away ...
4 Runner Ups
6 Semi Finals
59 matches won (second Lendl 39)
5 y.e.c's won with a 5-0 cleen-sheet (i think the next best is 3 apiece by Djoker/Sampras)
***EDIT*** Djoker does have 3/5 5-0s but Sampras has ZERO 0/5 (4-1) & he seemed to make a habit of defeating the same guy in the final that got him in the round robin. Becker x2 + Agassi x1 LOL 
Games won 1016 (Becker in @ 2nd on 706/Djoker tied @ 4th with Lendl on 639)
Fred even has the most aces lol (510 from 17 tournaments) Sampras 2nd @ 466 aces from 11 tournaments & may as well be first lol.
u.t.s has a nice little stats page to scroll through to really highlight Freddy's strengths in everything apart from the main stat of 6 y.e.c's. Really deserves to be the outright holder!