Stats All, Folks: Looking deeper into Statcast’s Launch Angle and Exit Velocity features

Over the last couple of years, you’ve probably noticed that baseball broadcasts and highlights have been sprinkled with factoids from Statcast, MLB’s data-collecting technology system.

Statcast, for those who don’t know, employs cameras and radar equipment in every major league ballpark to gather boatloads of data. It can track just about every aspect of the game you can think of — where each fielder is positioned and how quickly he moves, the length of a base runner’s lead and how well he accelerates, a pitcher’s exact release point and speed at which the ball leaves his hand, a home run’s hang time and distance, and so on.

Two of the most common Statcast features are Launch Angle and Exit Velocity. Let’s take a look at those today.

What is Launch Angle?

Launch Angle is the angle at which the ball comes off the bat. For context, a ball that comes off the bat in a perfectly straight line would be a zero-degree launch angle. A ball popped straight up over the batter’s head would be 90 degrees, and a ball hit straight down into the dirt directly under the bat would be -90 degrees.

In general, a ball hit at a Launch Angle of at least 30 degrees usually results in a fly ball or pop-up, and one hit at 10 degrees or fewer is a ground ball. The ideal Launch Angle for a hitter is in the 10-to-30 degrees range. These balls often turn into line drives or deep flies. So, power hitters usually have higher Launch Angles than ground ball hitters.

In 2016, the best average Launch Angle among hitters (minimum 200 balls in play) belonged to Brandon Moss, at 21.7 degrees. Moss hit 28 home runs in 413 at-bats for the St. Louis Cardinals. That’s according to the website Baseball Savant, which provides a comprehensive compilation of Statcast data.

One hitter in the majors actually had a negative average Launch Angle in 2016: Travis Jankowski of the San Diego Padres at -1.7 degrees. Unsurprisingly, Jankowski did not have a very good offensive season. He hit two home runs in 335 at-bats, posting a .313 slugging percentage.

Launch Angle isn’t just useful for evaluating hitters — it also tells us something about pitchers. Ground ball pitchers usually have a much lower Launch Angle against them than fly ball pitchers do. In 2016, among pitchers who had at least 200 balls in play against them, the lowest average Launch Angle was the -3.0 degrees against Mets closer Jeurys Familia. Familia is a ground ball specialist who allowed just one home run in 77 2/3 innings last year.

On the flip side was Oakland reliever Ryan Dull, who had the highest average Launch Angle against him at 21.4 degrees. He was tagged for 10 homers in 74 1/3 innings. Still, that didn’t prevent him from being effective — Dull posted a 2.42 ERA in 70 games.

Launch Angle and the Orioles

I’ll give you three guesses which Orioles pitcher had the lowest Launch Angle against him last year.

If all three of your guesses were Zach Britton, congratulations! You nailed it. (That one was a softball.) Britton’s mark was an absurd -8.5 degrees. His power sinker had hitters constantly beating the ball into the ground. It was almost impossible to put a ball into the air against Britton.

Here are the Orioles’ other Launch Angle leaders and trailers in 2016 (minimum 50 balls in play):

Highest average Launch Angle against (pitcher): Darren O’Day, 17.9 degrees

O’Day has spent much of his career as a ground ball guy, but he wasn’t his normal self in 2016. He gave up six home runs in 31 innings amidst an injury-plagued year.

Highest average Launch Angle (hitter): Chris Davis, 16.9 degrees

You might have thought Mark Trumbo, the MLB home run leader, would top the club in Launch Angle. But in fact his 14.8 degrees ranked third behind Davis — who utilizes an uppercut swing — and Matt Wieters (15.7).

Lowest average Launch Angle (hitter): Hyun Soo Kim, 6.0 degrees

Kim batted .302 in 2016, but many of his hits stayed low to the ground — short liners or ground balls. He has the type of swing designed to put the ball in play rather than drive it over the fence.

What is Exit Velocity?

Exit Velocity is the velocity at which the ball comes off the bat. The higher the Exit Velocity, the likelier a batter is to get a hit. Yes, hitting the ball hard is a good thing. (I’ll pause while you take meticulous notes.)

The top power hitters in baseball usually have an average Exit Velocity in the mid-90 mph range. Last season, among hitters with at least 200 balls in play, former Orioles slugger Nelson Cruz had the highest average Exit Velocity at 94.5 mph. The lowest average Exit Velocity belonged to Reds slap-hitting speedster Billy Hamilton (79.8 mph), whose game revolves around his legs, not his muscle.

Pitchers, of course, don’t want the ball hit hard against them, so they’re looking to keep opponents’ Exit Velocities as low as possible. In 2016, the best pitcher at doing so was the Rockies’ Tyler Anderson. He held hitters to an 83.9 mph average Exit Velocity.

Cleveland’s Danny Salazar was on the other opposite end of the spectrum, allowing an MLB-high 91.0 mph average Exit Velocity. Again, though, that’s not necessarily a death knell for a pitcher. Salazar still had a strong season, going 11-6 with a 3.87 ERA.

Exit Velocity and the Orioles

Let’s circle back to Trumbo. Launch Angle wasn’t the main factor in his home run barrage last year — but Exit Velocity certainly was.

Trumbo led Orioles hitters (and ranked seventh in the majors) with a 92.7 mph average Exit Velocity in 2016. In short, he hit the ball very hard, and it often went very far. And that was no coincidence. Trumbo pays attention to certain analytics such as Exit Velocity, and he incorporated them into his plate approach last year.

As for the team’s other Exit Velocity leaders and trailers (minimum 50 balls in play):

Lowest average Exit Velocity (hitter): Joey Rickard, 84.3 mph

The rookie Rickard was a bit of a punch-and-judy hitter in comparison to a lineup full of mashers. The ball didn’t come off his bat particularly hard, as reflected in his .696 OPS.

Highest average Exit Velocity against (pitcher): Wade Miley, 90.0 mph

As I discussed in my previous feature on FIP and BABIP, Miley gave up an inordinately high number of hits for the Orioles last year. Some of that can be chalked up to bad luck, but his Exit Velocity indicates that batters were hitting the ball hard against him, too.

Lowest average Exit Velocity against (pitcher): Donnie Hart, 82.3 mph

Hart was a rookie revelation for the Orioles in 2016, allowing just one run in his 18 1/3 innings of relief. Hart didn’t light up the radar gun, but neither did hitters against him.