by Matthew de Marte – June 12th, 2018
In 2015, when Statcast was released and launch angle became an official metric, some hitters, and a lot of hitting coaches, started using it to train hitters to lift the ball. In year 4 of the statcast era, launch angle still seems to be a mystery to most people around baseball. Due to the conservative history of baseball, old-school mentalities exist in coaches everywhere who either refuse to learn about the new perspective that statcast has given in evaluating and developing players, or are simply too stubborn to ever think that evolution could occur baseball. Whatever the case may be, the baseball industry has turned potentially one of its greatest training and development metrics into a buzzword that most of people who say it cannot even define. In this edition of Short-Stop analytics I want to dismiss some of the myths about launch angle and present a better way to analyze it.
First, I think it is important to clarify what exactly launch angle is. To make it simple, this is the definition you can find for launch angle in the glossary of MLB.com:
A few takeaways here. A launch angle is part of the OUTCOME of a swing. It is the result of a batted ball. So every batted ball in the history of baseball has produced a launch angle. With that being said, read this next sentence carefully: There is no such thing as a launch angle swing. It does not exist. A baseball swing is a baseball swing. If someone says this, that should tell you they do not know what launch angle is. If someone says this, do not take anything they say on the matter of launch angle seriously because it is a clear indication they never bothered learning what launch angle is.
After establishing a firm definition of launch angle,I want to introduce a new way to look at launch angle. Often when we look at launch angle, and I fall victim to this too, we just look at average launch angle. We assume if a player’s average launch angle has been raised, it is better for his overall production and makes him a better hitter. That is not necessarily true. Just because an average launch angle has increased does not mean a player is a better hitter. This could be due to the fact a player is hitting more pop-ups and hitting more soft fly balls that are outs. This would mean the player’s increase in average launch angle was a detriment to his overall production and made him a *worse* hitter. While I do not have specific examples of this, they surely are out their and that is not the point of this article.
Instead of looking at average launch angle on all batted balls, let’s look at just batted balls above 95 MPH. A batted ball, 95 MPH or harder is what is considered a hard hit ball by MLB. Through June 4th, 57.8% of hits during the 2018 season were hit 95 MPH or harder. When you look solely at extra base hits so far, 98.3% of extra base hits have been hit 95 MPH or harder. So, if you want to do damage, you have to hit the ball hard.
For me, when looking at launch angle, I think it is important to look at hard hit balls. Hard hit balls is where damage is done, and hard hit balls is where it is most important to optimize launch angle to ensure you are hitting as many extra base hits as possible. So, launch angle is important, but what’s most important is launch angle on hard hit balls. The following table shows average wOBA on balls hit 95+ MPH in 2018 based on their launch angle. Launch angles were rounded up to the nearest whole number for the sake of this data collection. Here are the top 20 most productive launch angles by wOBA in 2018 (Through June 11th) on batted balls hit 95+ MPH:
Every launch angle here is classified as a line drive or fly ball except for one. One player got lucky and chopped a ball into the ground at an insanely negative launch angle for a hit, but besides that, to produce the most players have to drive the ball in the air to get the most out of their hard hit balls. That one ground ball is clearly an outlier in the data. The story this table tells me is you want your hard hit balls to lie between about 10 and 34 degrees. The ten most productive launch angles on hard-hit ball are 23-32 degrees. To maximize a players output you want to see their hard hit balls hit in this bucket of launch angles as often as possible.
A player is going to hit pop-ups, a player is going to ground out and that will always affect their average launch angle. A player is going to make weak contact fairly often. Even Mike Trout has made soft contact 14.2% of the time during his career. Looking at average launch angle can be misleading because you should not really care about a player’s launch angle on soft contact because soft contact is almost always an out. Optimizing launch angle is based off a batted ball’s exit velocity which should be looked at for hard hit balls.
Here is an example of this kind of analysis. Kyle Schwarber and Joc Pederson are two improved hitters in 2018 compared to last year. Both hitters average launch angle on hard-hit balls are way down this year as you can see below:
This can tell a story, but I do not think it tells the whole story. Instead of looking at average launch angle on these batted balls, I would rather look at the % of batted balls these players hit 95+ MPH between a 10-35 launch angle comparing the two years. Both were around league average hitters in 2017 and are much improved hitters in 2018, so it is interesting to see the changes in their game:
Both players are being more efficient in how they launch the ball. While their average launch angles may be down, both players are hitting more hard hit balls between a 10-35 degree launch angle. These batted balls are line drives and fly balls where damage is done. Another thing to note is neither player is popping up hard hit balls. While elevating the ball is great, pop-ups are the worst kind of batted ball, and rarely ever produce a trip on base without something funky in the field happening. It is no secret. Both players hit a few pop-ups on hard hit balls in 2017, as you can see from the table. In 2018, neither player is doing so which must attribute to the decrease in their average launch angle on hard hit balls. So, while their average launch angles may be down, both players are much more efficient with how they are launching the ball, leading to upticks in production. Entering play on June 11th, Schwarber has a wRC+ of 130 compared to 102 last year, while Pederson’s wRC+ is 137 up from 100 last year.
So when looking at players’ launch angles, it is probably more important to look at how efficiently they are launching their hard-hit balls. Production comes from hitting the ball hard, and what you do when you hit the ball hard. When evaluating launch angle it is probably better to look at the efficiency of their launch angle on hard hit balls rather than their overall average.
Launch angle can be an extremely useful tool, but one cannot forget the context in which it is used. There is a lot more to launch angle than what was discussed in this piece. For instance, how low exit velocities influence optimal launch angle is a major factor, but that is a story for another time. When evaluating hitters with the ability to drive the ball, it is important to look at how efficiently they are launching their hard hit balls to understand if they are utilizing launch angle to the best of their ability. This can make a big difference in a player’s production as shown by the analysis of Schwarber and Pederson. Do not disregard launch angle, rather continue to learn about its importance and how it can be used to identify improved hitters, great hitters, as well as hitters who can make improvements to become more productive.