Mike Trout does not care about platoon splits

Mike Trout is the best player in baseball, and he has been since 2012. I know you don’t need me to tell you that. Countless articles have been written about him over the years, and understandably so. He might be one of the greatest talents that the game has ever seen, and believe it or not, such a player tends to generate a lot of content for writers. We all want to describe what makes him so special, particularly if it is especially rare.

Because baseball players still believe that sliding head first is a good idea, Trout suffered a thumb injury on May 28th that resulted in the first DL stint of his career. He ended up missing about a month and a half, which is roughly a quarter of the season. At the time, he was hitting .337/.461/.742. This bears repeating: he was slugging .742. He was on pace for 12 WAR. It is the kind of performance that could have easily won him another MVP, even from voters who still obstinately cling to team performance as a criterion.

The Angels’ other star player

Joe Nicholson-USA TODAY Sports

Mike Trout is the best player in baseball, but the Angels have benefitted from a different player becoming a star this season.

Since Trout did injure his thumb, I was concerned about how it would affect his power when he came back. All he has done since his return is hit .342/.468/.640 with 10 HR in 146 PAs, and he has walked more than he has struck out. That’s what I get for treating him like a mortal.

Trout’s season stats currently stand at .339/.464/.700 with 26 HR, good for a 204 wRC+. If he were able to maintain that 204 wRC+ over entire season — and he very well might at least once in the next few years — it would be only the 29th time a player achieved a wRC+ of greater than 200 in the live-ball era. The >200 wRC+ club has some pretty illustrious company. Furthermore, according to Baseball Reference, Trout has 5.4 WAR, which is about tied with Aaron Judge, who ranks third in the AL. Again, that is 5.4 WAR in in only 78 games played, which is roughly ²⁄₃ the playing time of the players above him.

As I recently marveled at the information above, I dug a little further into Trout’s stats, because what baseball fan wouldn’t want to do that? I noticed something peculiar about his career platoon splits.

That is a reverse split. Hitters do not have true-talent reverse splits. It is possible to see it happen over the course of one season because that is a small sample size, and anything can happen in small sample sizes. Occasionally you will see isolated examples, but the mechanics of hitting and pitching mean that hitters simply don’t have the baseline ability to hit same-handed pitchers better. Trout has done so for six seasons.

The analysis for the rest of this article will primarily be based on research presented in the sabermetric tome, The Book. In case you want to familiarize yourself further with the subject, Matt Klaassen once wrote about estimating true-talent hitter platoon splits at FanGraphs. I once covered the subject myself last year. The calculations in this article are done using this calculator made by Ian Malinowski. The projected wOBA will be taken from Steamer.

Mike Trout currently has a -3.6 percent platoon split. Since Trout’s first full season in 2012, the league split for right-handers has been 5.1 percent. Taking that number to regress Trout’s current splits and we get a split that is -0.48 percent. The regressed splits from the calculator still give Trout a higher wOBA against lefties... but it is only by two points of wOBA. That is basically zero. But that’s still a remarkable result, since it indicates that Trout is no weaker against righties than lefties.

What is especially surprising about this result is that great hitters tend to have larger platoon splits. As you might have noticed, platoon splits are measured in percentages, meaning that an average platoon split by wOBA for a .400 wOBA player will be greater than that of a .300 wOBA player. Of course a manager does not care about the platoon splits of great hitters. In other words, Trout is so good that he is a better option against a right-handed pitcher than almost any left-handed hitter in baseball.

According to The Book, a right-handed hitter needs 2,200 PA against left-handed pitchers in order for his true talent split to come out. Trout is not even half way there. To get an idea of what his future might hold in this regard, I decided to take a look at the splits of some of the greatest right-handed hitters in baseball history. I used the Baseball Reference Play Index, set the minimum PA to 7,500 in the live-ball era, and sorted by OPS+. (Baseball Reference does not use wRC+.)

It is probably pretty surprising that Mark McGwire is at the top of the list, but that is because he just barely made the cut on plate appearances. Had I set the PA limit any higher, Joe DiMaggio would have missed the cut! Then the real work began, because as great as the Play Index is, I am not aware of a method to sort by platoon splits.

(To add to the troubles of this exercise, Baseball Reference uses OPS instead of wOBA, even though they use the latter in their WAR calculations. OPS is fine for a quick, dirty measure of a hitter’s offense, but it is not appropriate for any serious sabermetric research. That also applies to measuring and regressing platoon splits. There is a wOBA calculator online but it is basically unusable for this exercise. As a result, as cool as it would have been to provide a table of platoon splits for some of the greatest right-handed hitters ever, I was limited in my capability to do so.)

I went through most of the names in the top 40 and checked the player’s career OPS versus lefties and career OPS versus righties. I expected to see that all of them were significantly better against left-handed pitching than right-handed pitching. I was almost right.

I came across two exceptions: Cuban legend Minnie Miñoso and Alex Rodríguez. Miñoso had virtually no platoon split over his 7,712 PA, which includes almost 2,200 against left-handed pitching. Rodríguez also had virtually no platoon split, and he did it in 12,207 PA.

As an analyst, the logical thing to say is that Trout’s true talent split is greater than what we have seen to date, and that we will see it grow to two or three percent, or even close to the average split. However, as a fan it is easy to see how special and unique Mike Trout is, and as a result, it is entirely possible that the rules don’t apply to him. I would not be the least bit surprised if Trout goes 20 years without showing a significant platoon split. If that’s bad analysis, I don’t apologize. Trout is just that special.