While perusing the offensive statistics of the Detroit Tigers Fangraphs page I looked over Jhonny Peralta's batting line. The Tigers starting shortstop has posted a triple-slash line of .259/.324/.411 which is good for a Weighted On Base Average (wOBA) of .319. When you compare him to the league average hitter, Peralta's production falls just shy of average as his 98 wRC+ indicates (100 would be perfectly league average).
I started to move on to other Tigers hitters before it dawned on me: Jhonny Peralta is a below-average hitter when considering all batters. However, compared to his own position, surely Peralta has to be above-average. Is it even really fair to compare him to the average batting line across the major leagues? Depends on the question, certainly, but I prefer a bit more context in my offensive statistics than just how each hitter fares once juxtaposed to the average hitter.
I've done the not-so-heavy work to compare each Tigers hitter to their positional average.
Firstly, I went to Baseball Prospectus' league batting by position page and culled the necessary data for each position in the American League. Then, using Fangraphs' GUTS section, I pulled the run values of each outcome of a plate appearance for a hitter in 2012. Using this, I created average wOBA's for each position on the diamond. Below are the positional average for this season:
The best hitters are, predictably, housed at DH and first base where any defensive flaws are completely or partially hidden. Beyond that, the outfield has featured some very even offensive performances. Without doing the heavy lifting, my guess is just a few years ago center field's offensive production wouldn't be as high as the corner outfield spots, but that's just a gut feeling. We shouldn't be surprised to see center field so strong offensively with the great players manning the position currently in both leagues: Austin Jackson, Mike Trout, Curtis Granderson, and Adam Jones have had stellar offensive campaigns in 2012 which says nothing of the seasons Andrew McCutchen and Dexter Fowler have had in the National League. I think we are currently in a "golden era" of young, stud center fielders much in the way the late 1990s was for shortstops.
There's a bit of a gap between the outfield and the non-first-base infield positions in offensive production. There is plenty of talk of how hard it is to find good offense at the catcher position, note that this year it is a better offensive position than both short stop and second base. The difference between the average AL catcher and the average AL short stop or second baseman is around 6 runs-per-650 plate appearances. That equates to just over half-a-win.
How does this affect the Tigers hitters? Well, a much lower bar offensively really improves the offensive season Jhonny Peralta has had this year. Here's how all of the Tigers players compare to their positions (minimum 100 plate appearances with the exception of Omar Infante):
Here we have each player's wOBA, the positional average wOBA. From that, we can convert it into runs (wRAA) and also into a rate stat which is wRC+ where 100 would be average and each point above/below is equal to one percent better/worse than average.
Peralta goes from a 98 wRC+ on Fangraphs to being 16% better than the average American League short stop. Meanwhile, Miguel Cabrera's phenomenal season gets a tiny bit better when his offense is compared to his AL peers. He moves from a 160 wRC+ to a 164 wRC+.
On the flip side, Prince Fielder drops a bit because of the higher offensive threshold at first base. He has a 145 wRC+ but against just first base, it drops to 134 -- still very, very good. Austin Jackson also drops from a 138 down to 134 position-adjusted wRC+.
Here, we can also see what a complete drain Delmon Young has been all. season. long. Compared to American League designated hitters -- you know, the ones paid specifically to hit a baseball for a living -- he has posted a 77 position-adjusted wRC+ which equates to being about 12.5 runs below his peers. On Fangraphs, he's "only" -5 runs offensively with his 87 wRC+ which is terrible. It just gets worse when you put it into the proper context of the fact that there are better solutions than someone who doesn't walk or hit for power. Oh yeah, did I mention that he's got an Isolated Power of 0.136 and the average DH has an IsoP of .179? If we put that on a 100-is-average scale, that grades out as a 76 IsoP+. Can't get on base, can't hit for power and still in the line up every day.
While he doesn't show well in the wRAA category due to his injury-plagued season, Andy Dirks, on a rate-stat performance has been the Tigers third best hitter behind Miggy and Prince. if we pro-rate the Tigers hitters wRAA numbers out to a full-season's worth of plate appearances (which is around 650), Dirks' season would equate to being 25.5 runs above positional average -- right on par with Prince Fielder. That is astonishing production. Dirks, baby!
Ryan Raburn: woof! That's about all that needs to be said.