Anyway, here's a quick stat in light of last night's final:
Sampras 18 final appearances in which he won 14 times and lost 4 times; therefore, he won 78% of his total Slam finals.
Federer 24 finals; won 17 times and lost 7 times; therefore, he won 71% of his total finals.
Nadal 19 finals, won 13 times and lost 6 times; therefore, 68% of his total finals.
Nadal's % will change of course in the future with each loss and win as he's the most likely player to face both going forward as Sampras is a retired player and Federer is on his way down, so don't feel his percentages are likely to change all that much in the future.
interesting stats there lady emma.

pistol was quite dominant in slam finals.
lendl was not. he lost 11 slam finals.