[IatricSB]

I personally don't believe they exist, but wonder if there's other combinations of things that can cause this. For example the player's "Desire to play for a winner", maybe his speed (if you have two identical players except for speed, will the faster player perform better), I've even considered things like weight/height or primary position, etc. Though I haven't studied it, it seems recently that my players labeled with a position of DH seem to have longer careers. Could be small sample sizes, but I try to look for hidden helpers in the various ratings that most take for granted.