Swing paths: the next frontier in baseball analytics?

Each team keeps their proprietary analytics close to the vest, as well they should. If your front office found an advantage over your opponents, why would you want to share it? Nevertheless, secrets always come out eventually, and two sources this past weekend may have let slip a little too much information.

On Sunday, FanGraph’s David Laurila released an interview with Yankees pitcher Zach Britton as part of his Sunday Notes column. The topic was about the superior information he has received with the Yankees compared to his former team, the Orioles.

“It’s (targeted) to each individual player. I don’t want to get into specifics, but some of it is how my ball moves, both my sinker and my slider, compared to different hitters’ swings.”

A day before this interview was released, Houston defeated Cleveland 3-1 in Game Two of the ALDS. Cleveland’s lone run came from a Francisco Lindor home run off Gerrit Cole. During the in-game dugout interview with Hazel Mae on TBS, Astros manager A.J. Hinch talked about how Cole’s slider lines up with Lindor’s swing path.

“Well, it’s probably a tough decision to go to the slider there. It’s kind of what Lindor’s swing path is gonna create. We like the other breaking ball a little better.”

The Yankees and Astros are considered to have two of the most advanced analytics departments in baseball. Apparently, they’re on the same wavelength with regards to batter vs. pitcher matchups. Each hitter has a different swing path, and each breaking ball has a unique path of its own. The more closely these paths align, the more likely the batter will make contact.

Let’s look a little more closely at the Lindor home run. Before we do, however, it’s worth noting that Gerrit Cole is one of the best pitchers in baseball and his slider is an outstanding pitch. He was especially dominant in this ALDS start, but he threw a particularly bad slider to a particularly good hitter, and that’s why he gave up one run instead of none. Any reference to his slider being bad refers to this one specific pitch to Lindor, and not his slider in general.

First of all, it really wasn’t a very good slider. Cole wanted to bust it in on Lindor’s hands, but he left it right in a damage area. Lindor crushed it 103.2 miles per hour and it traveled 386 feet. The TBS broadcast gave us this very convenient graphic showing the path of Cole’s slider to Lindor:

Ignoring for a moment that the pitch was poorly located, the path of the pitch appears to line up very well with the angle of Lindor’s bat. If Cole had been able to get the pitch further inside, there’s still a decent chance that Lindor could make contact. Maybe he wouldn’t have blasted it out of the ballpark, but anything can happen once the ball is put in play. It’s a less than ideal expected result for Cole and the Astros.

In the above quote, Hinch referenced Cole’s “other breaking ball.” That’s his curveball, and he uses them both about 20 percent of the time.

Needless to say, the two breaking pitches move differently. The curve has much more horizontal movement, while the slider has more vertical movement.

Based on Lindor’s swing path, we can infer that the Astros think his bat lines up better with vertical movement than horizontal. Hinch and the coaching staff probably warned Cole and catcher Martin Maldonado against calling sliders to Lindor for this reason. On this one particular pitch, they ignored the data and got burned for a homer.

Unlike Cole’s fairly even mix of breaking balls, Britton relies very heavily on his elite sinker. However, after his trade from the Orioles to the Yankees in late July, we can see him mixing in his slider a little more. (BrooksBaseball.net classifies Britton’s slider as a curve.)

Most likely, the Yankees convinced Britton that there are certain hitters whose swing paths align just right with his sinker, and if so, he should throw the slider instead. That could explain why he now throws the sinker five pitches out of every six instead of 19 out of 20, as he did in Baltimore.

Long before the age of analytics, teams kept scouting reports on which pitches each opposing hitter liked or disliked. For example, a report could say to throw sliders to a certain hitter but to stay away from changeups. But each pitcher’s slider behaves differently, as does each curve, cutter, or any other type of pitch. The release point, arm angle, velocity, and movement on one pitcher’s slider will differ from anyone else’s.

It’s very possible that Francisco Lindor might do well against a Gerrit Cole slider and not someone else’s slider, even though the pitches are called by the same name. It looks as though some teams— such as the Yankees and Astros— use this information to help their pitchers throw the right pitches to each hitter, and that other teams— like the Orioles— do not.

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Thanks to @Baseball_Jenn for research assistance.

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Daniel R. Epstein is an elementary special education teacher and president of the Somerset County Education Association. In addition to BtBS, he writes at www.OffTheBenchBaseball.com. Tweets @depstein1983