Could Participating in the Home Run Derby Really Mess Up Kris Bryant’s Swing?

Bobby Abreu set a Home Run Derby record when he blasted 41 homers at Comerica Park in 2005, more than the combined total of the next two closest competitors (David Ortiz and Pudge Rodriguez had 20 each). It was a magnificent display. It also caught a great deal of blame from the drop-off in Abreu’s power numbers that season.

Through the first half of the season, the Phillies slugger had recorded 18 home runs in 89 games; not a gaudy number, but pretty significant for a guy whose career high high was 31 in 2001. Following that record-setting performance in Detroit, however, Abreu tallied only 6 home runs in 73 second-half games.

In 2008, a clean-and-sober Josh Hamilton smacked 21 home runs in the first half of the season prior to a monumental round in the Derby that saw him delight viewers with 28 dingers in the first round at Yankee Stadium. But just as he fizzled in the contest, hitting 4 and 3 shots in the subsequent rounds, Hamilton launched only 11 homers for the Rangers in the 2nd half of that season.

I’m sure there are more examples, but I think you understand where I’m going here. Many have theorized that the Derby forces players to alter their swing, whether due to their competitive desires or to put on a show for the fans. Either way, there’s a pervading thought that those guys could have a hard time adjusting back to their normal swing upon returning to actual baseball.

I’ve never really believed that was true, as hitters who’ve worked entire lifetimes to perfect their swings shouldn’t be irreparably damaged by one evening of trying to hit nothing but home runs. But as much as I’ve dismissed it, there’s still a nagging sense of “what if?” That’s particularly true when it comes to Kris Bryant, who, as I wrote earlier, wants to participate in the 2015 Derby.

That said, I wanted to find a way to disprove the myth of Derby-induced struggles, perhaps as much to allay my latent fears as to simply satisfy my curiosity. I’m sure there are smarter and more statistically-inclined folks who could come up with a better method, but my research led me to what I believed to be the simplest conclusion.

Using a 10-year period, which, incidentally, begins with that aforementioned 2005 season, I looked at 1st half vs. second half splits, focusing primarily on home runs per at-bat. My goal was to compare league-wide splits to those of the players involved in the Home Run Derby to see whether there were appreciable drop-offs in the sample group in question.

I should note that I did not remove the Derby participants’ numbers from the league-wide totals I used, as such relatively small numbers would not throw off the calculations significantly. Perhaps my lack of care will lead to some statistical redundancy that invalidates my findings; if that’s true, I suppose a preemptive mea culpa is in order.

What I found in the league-wide splits was that, in general, power numbers improve in the second half of the season. This was true in all but three of the seasons I studied, though each of the last two seasons has seen a drop in HR/AB in 6% and 8%, respectively; the only other season with a drop was 2006, which saw only a 1.1% decrease.

On the whole for the period in question, HR/AB were at .02883 in the first half of the season and .02922 in the second half, a difference of only 1.344%. I had assumed there’d be a bit of a drop-off, but I guess dealing with warmer weather and pitchers who have put a little mileage on their arms can help to swing things in the hitters’ favor, pun intended.

My initial plan was to take into account all the contestants in all 10 seasons, though I quickly backed down from that given the amount of information and my inability to pare it down efficiently. Besides, I figured, the impact of a home-run-hitting contest — whether real or imagined — is going to be greatest on those who participate the longest.

With that in mind, I focused on the two finalists in each season. Yes, I know it’s a little dangerous to draw conclusions based on only 2 players, but when we multiply that 10 seasons, we’ve got 20 players seasons from which to cull data. Besides, I’m reasonably sure this study isn’t going to be picked up by Baseball Prospectus so it’s really just about having some fun.

My initial findings were interesting, as I discovered that there does appear to be a correlation between Derby participation and a drop-off in 2nd-half power numbers. As a group, the 19 finalists (I removed Joey Bats’ 2012 numbers because he was injured early in the 2nd half of the season and only got 17 AB’s with no home runs) had a HR/AB mark of .053 in the 1st half and only .048 in the second.

But in digging a little deeper, I found an even more interesting trend. Derby winners over the last 10 years have actually improved their power numbers in the second halves, from .0542 to .0570. That means, then, that the second-place finishers — highlighted by flagging performances from Bryce Harper, Adrian Gonzalez, Hanley Ramirez, Abreu, and Hamilton — have really plummeted from a mark of .051 to .0372.

Huh, maybe finishing second in the Home Run Derby is like being the Super Bowl loser or Gil Hicks’ date. You’re in there with some pressure and when you’re done, you’re just not the same as before. You’re changed. But as much as I’d love to close my study out with a Mallrats reference, it just felt like I was in a very uncomfortable place, like the back of a Volkswagen.

So it was that I went back to the tedium of looking up the splits for the other participants, all 61 of them (Tulo’s injury last year ruled him out). You can’t see me right now, but I’ve got the back of my hand up to my forehand in a melodramatic swooning charade. I hope you all appreciate the efforts I’ve gone through to bring you this highly sought-after data.

Lo and behold, Derby participants went on to see an average drop in HR/AB of 15.63% in the second half of the season in which they participated. Only 24 of the 80 player-seasons I reviewed showed an uptick in power, with Ryan Howard accounting for 3 of those. That means 56 players saw a reduction in their power.

Despite the fairly conclusive stats to refute my original assertion that the Derby does not hurt players’ swings, I’m not willing to completely abandon my beliefs. Several factors are still at play here; maybe pitchers got a book on a guy who busted out unexpectedly in the first half or the hitter simply regressed, perhaps nagging injuries prevented a repeat of the first half.

This isn’t a new topic, after all, but it does appear to have gotten short shrift. Sure, there are some articles here and there about it and I’ve checked a few of them out. But other than telling me that I should have just looked at ISO, there’s not a great deal of really in-depth info available. I did, however, find a nice piece by Neil Greenberg that ran in the Washington Post just about a year ago.

In it, he concludes that it’s not the Derby itself that causes the downturn in hitter performance, but several factors inherent in regression. As Greenberg writes:

Home run derby participants hit the ball almost the same both before and after the event. The biggest difference is in the home run-to-fly ball ratio, which would explain the decrease in batting average and isolated power.

The notion that participating in the home run derby can ruin your swing is a myth. Instead, it looks like hitters just get a little less lucky on the fly balls leaving the yard.

While it’s true that Derby participants do see decreased performance in the second half of the season, particularly in the face of the general improvement of the rest of the hitters across both leagues, it’s probably due more to the types of players in question. But the myth persists because it’s too convenient to relate the Derby to a downturn in production.

So fear not, Cubs fans, taking part in the Home Run Derby won’t ruin Kris Bryant. At least, no more than it did Crush Davis, Bobby Abreu, or Josh Hamilton. Or, uh, Brandon Inge. Think about Bryant’s swing too: he’s about as far from the Javy Baez, max-effort hack as you’ll find. In fact, he’s so buttery smooth with that stroke that you almost wonder how he’s able to generate so much power.

I really want to see Bryant put on a show though, just as long as he doesn’t finish second.