In an ideal situation a developing player should be competing at a level slightly higher than where he has already succeeded. And I think that's fairly easy to do in the minor league system that's in place today. However, the jump from AAA to MLB is a bigger jump than moving up one class in the minors. For example, not many AAA batters can do much to a straight 95 fastball, but in MLB there are lots of players who turn those into 400-foot dingers.