Chase Headley on Switch Hitting for Power in San Diego

When we, as fans, use anecdotal evidence in our quest for baseball truths, we often over-emphasize iconic moments. Our sample degrades into big moments we can remember. So we turn to data to give us an unbiased look at the facts. But when a hitter evaluates himself and his swing, he usually turns to his memory for help. And though that evidence is anecdotal as well, the sample is huge — that hitter spends most of his time thinking about hitting, and all of his time being himself.

So it’s no surprise that Chase Headley knows best why Chase Headley showed more power in 2012. And that the slugger has had a complicated history when it comes to using data.

So how did he hit for more power last year? “I would say that I was able to pull the ball in the air more frequently than I did in years past — not necessarily pulling the ball more, but being able to elevate the ball more from that side — that would be my best guess,” was Headley’s intuitive answer. The numbers agree that he pulled the ball more to the outfield from the left side last year:

The numbers to right field alone represent a big change, but when seen in tandem with his opposite field numbers, they are even more impressive. Headley says that pulling the ball with power to the outfield was really just something that came from “hitting the ball correctly,” or hitting the ball with backspin.

Switch hitters have twice the work to do, in effect. “My swing is completely different from each side of the plate,” said Headley, and that echoes some of the things Dexter Fowler exhibits in his splits. Headley goes so far as to call himself “two different hitters.”

Generally, Headley feels he pulls the ball more from the right side, and swings and misses more perhaps. He doesn’t know these things for sure, but that’s his feeling. Is this true? Is there evidence that he’s finally converging his approaches from the two sides? He does admit that’s a goal.

Well, Headley wasn’t going to bat one thousand, maybe. He strikes out as a lefty more consistently. But when you look at his batted ball mix from the right side, you start to see something interesting:

To summarize, it looks like Headley has become more of a pull hitter and hit more ground balls from the left side since 2009. It also looks like those changes have made his profiles from the left and the right more similar.

For the most part, Headley’s intuition about himself has been correct. And when I asked him if he used much data in the process of becoming a better hitter, he said he didn’t, not often at least. But once upon a time, he did see something — the batting average on ground balls and fly balls in San Diego. That, and knowledge of the difficulty of showing lefty power in PetCo, caused Headley to change his approach.

“I made some adjustments when I got here, because this park is so big and conducive to hitting the ball lower on the ground, and I worked on that so hard — hitting the ball the other way, hitting on a lower trajectory — that I almost forgot how to hit the ball the way I used to, and last year I decided I wanted to get back to hitting the way I used to, and we worked on my swing path and backspin in the offseason,” Headley said about getting to PetCo and changing his approach.

That work was well worth it, no matter if the stat he first saw was a bit misleading. Ground balls are always going to have a better batting average than fly balls, but the slugging on fly balls undoes much of that difference. But as we found from talking to Joey Votto, hitting to all fields and finding a level swing plane are valuable things, so his time wasn’t wasted. Even if adding some pull power back into his game looks like a no-brainer now.

Every day, Chase Headley is gathering data in his own way. And every day, he’s working towards having the best possible approach, and duplicating it from both sides of the plate. For the most part, he’s done it without data, but the numbers really like what he’s done with his game.