I'm working on my pre-rankings, and I've always had difficulty factoring in the "rate" stats into my rankings.

I'm coming up with point values for each category in a pretty standard statistical way ((projected value - league average)/std dev)) which works fine for all counting stat categories, but doesn't work as well for rate stats because it doesn't factor in the number of AB or number of innings pitched. So I'm just basically ignoring AB (which isn't a big deal since most guys on fantasy lineups will have about 400-600 AB), and also ignoring IP. That sucks because my model is overranking relievers who pitch 1/3 the innings, and underrating pitchers who throw 230 innings. I could just add a 6th category and factor in innings pitched (doing the same STD Dev calculation), but then it would overrate pitches compared to to hitters (since they'd have 6 categories instead of 5)

How do you folks build those into the equation?