Use It or Lose It: The Ability of Lefty Mashers to Hit RHP

There has been a lot of good dialogue regarding certain players such as Matt Joyce and Kelly Shoppach over the past week  and  their situational usage in platoon roles. Shoppach in particular was simply awful versus right-handed pitching in 2010. How awful? Awful to the tune of a .210 wOBA and 54.3% strikeout rate, much worse than his career split numbers against righties: .302 and 39.1%. It's easy to jump to the conclusion that Joe Maddon used Shoppach terribly last year, allowing him to face righties nearly half the time (45%), but digging a little deeper reveals that the skipper was far more delicate in handling the burly catcher's platoon usage than his previous managers. Shoppach had faced right-handed pitching in 68-79% of his plate appearances in each of the previous four seasons with nowhere near the dreadful results.

We all know Maddon loves to maximize his daily lineups by trying to take advantage of any platoon splits available, be it handedness or opposing pitcher batted-ball profiles. Over the past three years the Rays have had four veteran  "lefty mashers", or right-handed platoon hitters: Gabe Kapler, Kelly Shoppach, Jonny Gomes, and (to a lesser extent) Jason Bartlett. Remembering Kapler's laughable 2009 campaign against right-handers, I thought it worth a quick look to see what the potential downfall was to an individual's ability to hit the same-handed pitching when given the opportunity less frequently. Each veteran had his most favorable usage to the team (lowest % of plate appearances versus RHP) under the guidance of Joe Maddon. Did this usage make them worse against right-handed pitchers, though?

I looked at the last five years of each individual when they had at least 50 plate appearance against right-handed pitching. The results can be found in the chart at the top of the article or in the tables below.

Gomes, Shoppach, and Kapler all saw far fewer right-handed pitchers with Maddon, and all posted their most laughable wOBA against righties. Of course, this can lead to a chicken or egg argument, since one could argue that their usage was reduced because they were struggling. However, given Maddon's liberal use of platoons, I'm willing to hypothesize that reduced usage was the plan for these lefty mashers.

Its certainly a quick and dirty look and far from scientific, and the sample sizes qualify as silly. Nevertheless, I think it's interesting and could be worth examining further. I'm not suggesting that receiving less than 50% of your plate appearances versus same-handed pitching will render wOBAs of .211, but a larger study very well may suggest wider platoon splits than you typically would expect.

Intuitively, we know left-handed hitters have wider platoon splits than right-handers, since they are less used to seeing same-handed pitching. However, if you take the bat out of a right-handers hands in a platoon role, you might expect their same-handed skill to more closely resemble their uncomfortable southpaw friends. I am unsure of what it ultimately means, but I am a bit more inclined to think that if Kelly Shoppach faces south of 50% righties again, his wOBA in those situations may not regress to the degree many are expecting. If his usage was to increase, though, that could possibly be the case.

If I was to suggest how to best use Shoppach against righties, I would look at the power//finesse splits on Baseball-Reference.com. I know these splits are unpopular to some under the rationale that power pitchers are generally better, but we can still try to take some information compared to the league average margin. For Shoppach's career he has posted a slash line of .191/.304/.355 against power pitchers, dreadful results. Against finesse pitchers he sits comfortably at .270/.331/.488. That's a .160 point swing in OPS over his career between the pitcher classifications. The league average OPS is .690 vs power pitchers and .762 vs. finesse, a difference of .072 or less than half of Shoppach's career margin. Given John Jaso's superior contact skills, it would make sense to play him against all right-handed power pitchers, but I'd suggest giving Shoppach some looks against the softies. Closer to a 50/50 playing time split may just prove more optimal to the club after all.