In the Infinite Thread about Lyle Overbay, we talked a lot about defense, since it's fairly obvious that that's where his primary surplus value lies relative to the other potential first basemen on the roster. Among other things, we discussed his value as a receiver, and there was talk about whether Steve Pearce, as a "short" (5-foot-11) first baseman, was at a disadvantage as a receiver.
What we didn't discuss was this Fangraphs article about first basemen and "scoops," or general ability to catch errant throws. In it, we learn two relevant facts: One is that the average lefty first baseman over 6-foot-1 (that's Lyle) is worth 1.2 runs/season relative to average, while the average righty first baseman under 6-foot-1 (that's Pearce) is worth 0.8 runs/season less than average. The other is that Overbay has been one of the best receivers in baseball, saving an average of 2.5 runs per season (actually, per 1000 throws, which is about the same) relative to average.
Now, assuming that Pearce is an average short righty, then that's an expected surplus of ~3.3 runs saved based purely on saved throws. Given the Pirates' pitchers and other infielders, I'd guess that number should be a bit higher, but it's certainly in the neighborhood. In terms of range, the two are probably about equivalent - Pearce's sample sizes are small, but positive, and Overbay's range will presumably be in decline. Even if you give a slight edge to Overbay, it's hard to see him worth more than half a win on defense. If ZiPS is correct about the two, then it sure looks like the Pirates overpaid. Which, I might add, has been my contention since the moment I found out about the contract value.