http://www.fangraphs.com/library/pitchin...
You could look at Opponent OPS to evaluate pitchers. Clayton Kershaw led the majors with a .502 Opponent OPS last season while Max Scherzer led the AL with .564 Opponent OPS.
ESPN has the stat on their website:
http://espn.go.com/mlb/stats/pitching/_/...
You can look at OPS against the pitcher if you want.
OPS is offense only, and wOBA is a better stat for that. For a position player, you also want to look at defense and baserunning.
For a pitcher, your most interested in pitching only, and for that, stats like FIP/xFIP, tERA, and SIERA are much better than wins, ERA, and the other traditional pitcher stats.
If OPS roughly represents the production of a position player, than what basic stat can be used for pitching statistics?
