Posted By:
GlennGil and Jay,
Now I agree with most of what you are saying. My problem is that for me, and a few others (none of my statistics students though), there is a romance to statistics as well as to baseball. Please feel free to ignore the remainder of this post if you aren't aroused by thoughts of repeated measures ANOVA, factor extraction with oblimin rotation, multiple regression, or a little old-fashioned semi-parial correlation.
That said, I don't understand why somone would be turned off by a discussion of OPS but not of BA, both of which are derivative of purer statistics that come only in whole numbers, unless it is for the nostalgia of BA. If you want to look at just a single variable not derived from others then you should look at wins for a pitcher (making Cy Young the greatest ever) and hits for a batter (making Pete Rose the greatest ever; one could also make a case for Rickey Henderson with the runs record or Hank Aaron with RBI). But that I think we would agree is absurd, so we combine these numbers with career losses, at-bats, plate appearances, total bases, etc. Each time we add a new variable into the mix the new measure is a little more complicated, but it also does a better job of approximating a true measure of the player's (pitcher's, slugger's, hitter's) quality, or else we dispose of the new statistic, as we would with, e.g., [(HR + 2B - 3B)/AB] which really isn't a good measure of anything useful, not useful to me anyway. The goal is to strike a balance in the tradeoff between the simplicity of the model and its utility at discriminating accurately among players of differing ability. Some may find OPS too unwieldy to be a worthy figure in the debate. I feel otherwise. The only question is, "Does OPS do a better ENOUGH job at discriminating offensive ability to justify the addition of the additional composite variables?"
OPS = [(H + BB + HBP) / (AB + BB + HBP + SF)] + {[1B + 2(2B) + 3(3B) + 4(HR)]/AB}
And it works so well. To me that is beautiful, maybe not as much as a clean 6-4-3 double play on a freshly-manicured infield, but beautiful nonetheless.