Switch hitters often prefer to hit from one side of the plate or another (even though they’ve learned to switch hit, one hitting from one side is still more natural to them), but we’re not used to seeing large platoon splits from them. Victor Martinez, for example, has a career OPS of .828 when hitting as a left hander, and a career OPS of .851 when in the right-handed batter’s box.
Carlos Guillen, another Detroit switch hitter, has a little bit larger split (his career OPS is .815 from the left side and .769 from the right), but it’s still not that big of a split. Certainly not as big as a hitter who strictly hits from one side of the plate. Magglio Ordonez, for example, has hit .943 against lefties and .854 against righties in his career (always from the right-handed side of the plate).
Switch hitting is a great skill for a hitter because it eats into the platoon advantage that same-handed pitchers hold. This is why it is shocking to discover how large Wilson Betemit’s splits are as a switch hitter. For his career, Betemit has an OPS of .808 as a left handed hitter (against right handed pitching) and an OPS of .679 as a right handed hitter (against left handed pitching). Splits like this beg the question: is Betemit gaining any advantage by switch hitting, or should he simply always hit left handed?
To answer this question, we need a metric that’s a bit more precise than OPS. We need to employ weighted on base average (wOBA). It’s a nice little metric that carefully weighs each outcome (single, double, walk, etc.) against a carefully calculated run value. The scale of wOBA is the same as on-base percentage, so it’s easy enough to think about. The general rule of thumb (although offense has been on the decline the past couple of years) is .330 is about average, .400 is amazing, and below .300 is poor.
Here’s Wilson Betemit’s career platoon split as described by wOBA:
|vs RHP as LHB
vs LHP as RHB
The average major league (non switch hitting) batter has a platoon split of about .030 wOBA points. We’ve observed Betemit’s split to be around 0.039 points, so it doesn’t initially seem that he’s benefitting from switch hitting at all. It even seems like it might be hurting him. But even though he’s acquired over 1800 plate appearances in his career, we can’t trust that his observed split is the same as his true ability. We must regress these numbers toward the league average before we can form any sound conclusions.
It has been determined that wOBA should be regressed 50% of the way toward league average once the switch hitter has accumulated 600 plate appearances against left handed pitching. Betemit only has 446, so we’ll regress 57%. Here are the regressed splits:
|vs RHP as LHB
vs LHP as RHB
So we really don’t have enough information to actually say that Betemit’s switch hitting is hurting him. The regressed split is only .016, and that number falls well within a traditional hitter’s expect split range.
So for now it would be unwise to advise Betemit against switch hitting, but if his platoon splits continue to be so drastic, he may want to abandon the practice.