It's not happening slowly, it's already happened. Look at the ages of the players in the top 25 right now; 1 player in the top 10 under 26 which is Del Po at 25. Only 3 other players in the top 25 are under 26. Forgive my juvenile math but you're telling me that 21 out of 25 players on the tour right now are already in or entering old age within 12 months? I can't figure out the percentage which that is but I'm sure a more mathematically astute forum member can figure it out. I personally don't see one player under the age of 26 winning a slam for at least a few years. The only player who has a chance is Del Po right now and he has exactly 364 days to win a slam and after that I don't see it happening with anyone else. Old age 20 years ago is now the prime age.