Jason, I like to consider myself something of a recovering baseball stat nerd, and I hadn’t heard of wOBA. But in doing a bit of reading on it, I don’t know if I like it. It seems like the idea was to eliminate the scale imbalance in OPS — correcting for its lopsidedness in favor of SLG — and that’s all well and good. But I can’t tell if the “run value” weights that are built into are the result of the kind of endless tinkering and educating guessing that informed Bill James’ and his ilk’s early contributions to sabremetrics (think the “runs created” or “Pythagorean” wins formula, or the discovery that .120 + line-drive percentage (eBABIP) is a very good predictor of batting average on balls in play (BABIP)), or if something more thoroughly empirical and systematic is going on. We want stats that are not only scrutable (even casual fans know that .302/.386 /.570, A-Rod’s career line, represents an all-time great hitter) but also predictive of a player’s value to his team. The genius of Billy Beane’s focus on OBP was that his staff actually did the work and figured out that OBP correlates more highly with scoring runs, and thus winning, than does batting average. The brilliance of of “Defense Independent Pitching Statistics” (DIPS) is that they isolate the outcomes a pitcher exerts some control over from those he doesn’t (Also, I can’t find the data at the moment, but a few years ago I ran some multi-year intraclass correlations on DIPS for every pitcher in baseball and showed that there was a fair degree of year-to-year consistency over three-year and five-year stretches. Like I said, recovering nerd).

The downside of this sort of stat is — you have to keep doing the work. That is, you have to keep updating the empirical data you used to get the weights. Complex stats like the Davenport translations are excellent because the databases they use are both enormous and dynamic. Offensive contexts change for a lot of reasons — “dead” versus “live” balls, PEDs, ballpark effects, lowering the mound etc. — and these let you do comparisons across various contexts and eras.