later age. You can have a baseball player who is great at 19 but never turns into anything because he doesn't continue to develop as he hits his early 20's. You can also have young baseball players that are middle of the pack make a huge jump in development in their mid 20's. I guess that can be because for position players their power often develops later. For pitchers their success may be dependent on whether or not they develop a strong third or fourth pitch, and they may not do that until mid or even late 20's.

Football is probably the toughest jump in terms of the level of competition though - regardless of your own development the speed and strength jump from college to the NFL is HUGE.