Pirate first basemen were dreadful last year. Despite hitting 18 home runs and 30 doubles their combined wOBA was just 0.290. (I'm plugging the combined numbers into a version of Tom Tango's wOBA calculator.) Just by way of comparison, note that Ronny Cedeno's wOBA was 0.325, a bit below league average. Nor was the fielding anything to write home about. Pearce and Clement were actually OK, but Garrett Jones proved that his future lay in the outfield.
So, cue October. The Pirates find themselves with three first base candidates: Steve Pearce, who was injured just when he appeared to be making a move; Jeff Clement, with limited experience (majors or minors) at first and a very unimpressive batting line; and John Bowker, sporting a career OPS of 682. The Pirates sign Lyle Overbay, to near universal lack of enthusiasm.
A good fielder, Overbay does not overwhelm at the plate. He does, though, display a hefty platoon split. Hitting against right handers Overbay averaged 30 doubles, 15 home runs, and 61 walks over the last three years, for a wOBA of 0.370. (This is a weighted average, with last year weighted 41.7%, the year before weighted 33.3%, and the first year 25.0%.) Against left handers Overbay averaged 2 doubles, 3 home runs, and 10 walks for a wOBA of 0.273 (in less than a third as many plate appearances).
Hmm, how might a platoon or semi-platoon with Steve Pearce work? The same three year average shows Pearce with a wOBA of 0.388 against left handers and 0.253 against right handers. This is a very small sample for Pearce, but if he doesn't have a wOBA of at least 0.330 against left handers, he's unlikely to be in the majors. Put these two together with 450 plate appearances for Overbay and 250 for Pearce and you could get a first base position with 58 doubles, 22 home runs, 92 walks, and a wOBA of 0.373. You could get more production, or you could get less. Pearce is the real wild card here. Even with less production the platoon would represent a vast improvement on offense and defense.
So, what Adrian Gonzalez do at San Diego last year? He had 33 doubles, 31 home runs, 93 walks, and a wOBA of 0.375. It could happen in Pittsburgh. I'm allowed to have fantasies in January, right?