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:

As LHB Pull Center Opposite
2009 45.2% 30.4% 24.3%
2010 37.1% 36.1% 26.8%
2011 41.5% 29.8% 28.8%
2012 48.0% 32.4% 19.6%

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:

GB/FB as L GB/FB as R Pull/Oppo as R Pull/Oppo as L
2009 1.01 1.80 2.24 1.86
2010 1.19 2.00 2.00 1.38
2011 1.25 1.63 1.48 1.44
2012 1.46 1.70 1.77 2.45

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.

With a phone full of pictures of pitchers' fingers, strange beers, and his two toddler sons, Eno Sarris can be found at the ballpark or a brewery most days. Read him here, writing about the A's or Giants at The Athletic, or about beer at October. Follow him on Twitter @enosarris if you can handle the sandwiches and inanity.

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Persnickety Grammar Guy
10 years ago

Eno, good info, but – “data like”, not “data likes”. Not a good error if you’re doing statistical analysis.

Clint Robinson
10 years ago

While wasting away in AAA, I have had time to look up data in the dictionary. Turns out, both singular and plural are correct.

Maybe you should educate yourself before criticizing people. You’re no better than Eric Hosmer.

Section: “Usage Discussion of DATA”

“Data leads a life of its own quite independent of datum, of which it was originally the plural. It occurs in two constructions: as a plural noun (like earnings), taking a plural verb and plural modifiers (as these, many, a few) but not cardinal numbers, and serving as a referent for plural pronouns (as they, them); and as an abstract mass noun (like information), taking a singular verb and singular modifiers (as this, much, little), and being referred to by a singular pronoun (it). Both constructions are standard. The plural construction is more common in print, evidently because the house style of several publishers mandates it.”

Switch Hitting for Power in San Diego is as fruitful as....
10 years ago
Reply to  Clint Robinson

…expecting to make your fortune as Clint Robinson’s agent

Clint Robinson
10 years ago

Damn you, Gaby Sanchez, with your fancy shoes and your anonymous internet commenting.

Persnickety Grammar Guy
10 years ago
Reply to  Clint Robinson

Fair enough, but no statistician would use that construction. Hence the “statistical analysis” caveat.

10 years ago

no offense, but go away.

You Grammar Police are almost as bad as people who wish to throw in their worthless political comments in sporting blogs.

While I agree the internet has destroyed the language, I come to sports blogging sites to relax. Sorry if I offended you.