In case you can’t tell, Ian Happ’s 2022 All-Star season has me transfixed. Is there something in the water over at Wrigley this year where this guy suddenly became the future cornerstone of a Cub’s rebuild? I won’t be investigating the water quality of Chicago’s Northside, but I will take a look at Happ’s career through the lens of launch angles and exit velocities.
If that sounds sort of physics-y…it’s because it is. Growing up, I remember constantly being told during batting practice to have a level swing and avoid hitting the ball in the air. The aim was line drives and hard grounders, because that’s how you got on base, right?
The advent of sabermetrics has brought about a significant change in how teams and analysts think about hitting. A double is more valuable than a single or a walk, a triple is more valuable than those, and a home run is more valuable than all of those. When you take a step back, it makes sense. Extra base hits put runners into better position to score and home runs generates runs in one at-bat. And how do you hit more doubles, triples and home runs? You hit the ball in the air more often.
Enter launch angles and exit velocities. They’re pretty self-explanatory terms — launch angles are the angles a ball travels after it leaves the hitter’s bat and the exit velocity is how fast that ball is traveling after batter impact. Fly balls and line drives have higher launch angles than ground balls and usually have faster exit velocities, too. Do harder hit balls generate more hits? Potentially — that’s an analysis for another day.
What I’m curious about now is how Happ’s average launch angles and exit velocities have changed, if at all, over the course of his career and if there’s something significant in how’s been hitting the ball this season. I am aware that All-Star selections aren’t just based on hitting the baseball, but Happ’s performance at the plate is what I’m most interested in right now.
What I did first was run an analysis and create some visualizations of Happ’s balls put in play, their exit velocities and launch angles, as well as his estimated batting average on those balls he put in play. The lighter colored dots indicate higher estimated batting averages, while the darker dots are low estimated batting averages. I ran this analysis for his 2017–2022 season.
It looks like Happ has hit the ball harder the last 2 seasons and has generally better launch angles than in his previous seasons. In 2021 and 2022 he’s got a nice cluster of balls in play that have both high exit velocities and “sweet spot” launch angles (line drives). The fly balls he’s hit have generally been slower off the bat than his line drives but harder than his grounders. Let’s take a look at his career averages next.
Interestingly, Happ’s average launch angles were higher his first 3 seasons with the Cubs, while his average launch speeds have generally stayed fairly consistent throughout his career. This season, Happ is right in the middle of the pack in both average launch angle and average exit velocity compared with the rest of the league.
Actually, he’s below average compared to the rest of the league in both average launch angle and exit velocity. What’s interesting to see are the correlations between those two metrics and expected batting average. The higher a batter’s average launch angle, the lower their expected batting average will be. But the higher their average exit velocity, the higher their expected batting average. Happ may have found the sweet spot in both these metrics this year and seems to be over-performing. Comparing his 2023 season to the last six seasons will be interesting.