My problem with PB right now is the wide range of results for a given player.
If you have McGwire in one league hit 95 Hr's and in another league hit 35 hr's you get an average that is very close to his "real" life numbers.
But those are very poor results if your game algorithm is based upon actual player performances.
The results of every atbat should be based upon the pitcher's numbers averaged with the batter's numbers (taking into account lefty/righty situations). Factor in small variations for fielding range, ballpark stats, and other variances and you should have a fairly accurate result, even within just 100 plate appearances.
Tim Wilde