Earlier this season, when Michael Cuddyer was playing some at third base, I suggested that the stress of playing the more difficult defensive position was sapping his bat.
Here, according to Baseball Reference, are Cuddyer's career averages by defensive position, listed in order of plate appearances (at least 100 plate appearances):
RF (2,411 plate appearances): BA .269/ OBP .343/ SLG .446
3B (610): .261/.327/.430
1B (424): .296/.368/.522
2B (184): .248/.330/.429
He's got a bit more than 100 other plate appearances scattered about left field, center field, DH, and pinch-hitting, not enough to put any weight at all on.
A similar pattern is to be seen in this season's splits for him.
Even if these splits would hold up over time — Cuddyer hasn't had even the equivalent of a full season at first base — I wouldn't bench a healthy Justin Morneau to give the first base job to him. But the numbers do suggest that he's best at first base — and that his offense gets better when he has less to do defensively.