I'd be more interested in splits (batters faced from each side, not the results). I'm probably in a minority, but I don't think splits necessarily tell you anything b/c of the small sample size, and you don't know if your player faced a lot of strong reverse players. I've had a number of players "turn around" after keeping them (sometimes too long) and some whose stats didn't match their splits after knowing what year I had due to injury.
This is especially true of relief pitchers b/c of the limited innings they pitch.
Gibby didn't hit LHP too well in '85 too.
Playing the '05 game will make this even more obvious---some of the aberrations are funny sometimes.