Exit Velocity and Launch Angle: Do They Matter? An Analysis of the 2021 Yankees

By Andy Singer

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Photo Credit: Frank Franklin II, AP Photo

This was an undeniably difficult year to be a Yankee fan. Fans and observers alike can be forgiven for allowing emotion to override more analytical tendencies. There was a lot that went wrong in 2021, and everyone is entitled to their opinion regarding the chief issues that tanked the Yankee season. Today though, I wanted to tackle one of the subjects of fans’ ire.

Many have accused the Yankee front office of being too married to modern methods of statistical analysis for all decisions. Chief among the derided statistics dear to the Yankees has been Exit Velocity and Launch Angle. There is little question but that the Yankees clearly committed to finding guys who would be classified as “Statcast Monsters,” guys who produced loud contact at optimal launch conditions.

It is certainly true that despite targeting players who produced loud contact with great launch angles, the Yankees still didn’t win enough games to still be playing at this point in October. Fans couldn’t stand hearing about Exit Velocity and Launch Angle in 2021, while the Yankee front office remained committed to finding guys who excelled in those arenas. So, who was right? Was anyone right? I sought to find the answers to these questions with clear, unbiased eyes.

I will freely admit that I am statistically inclined, both in my professional and personal life, so proper analytical methods and analysis appeals to me. However, I also have played baseball at a high level, and I understand that there is more to the game than bottom-line numbers. I had read some statistical analysis with regards to the correlation between Exit Velocity, Launch Angle, and offensive value, but much of that research is years old at this point. I wanted to know if it still had validity in 2021. For the sake of full disclosure, I nearly wrote this article multiple times during the 2021 regular season, but it felt hypocritical to write at any of those times given that I’m the guy that consistently throws out small sample sizes as an argument against statistical analysis. Now that we have a full season of data though, I think dissecting the Yankees’ 2021 offense through the lens of Exit Velocity and Launch Angle makes a lot of sense. Before I give you the numbers, please know that I am equally ready to say that the Yankees really do need to look elsewhere for real offensive value, or that their policies were just. With that out of the way, let’s discuss the findings.

Exit Velocity and Total Offensive Value

Among the questions I asked when I started to dig for data was the following: how well does Exit Velocity correlate with total offensive value? The first part of this exercise was simple: what was the average Exit Velocity for each of the players in question? The second part of the equation was more difficult. I needed to decide which offensive metric I would use for the Y-Axis of my exercise. I considered using OPS+, wRC+, and wOBA, all statistical measurements that seek to identify total offensive value for a given season using runs scored, contact, power, outs caused, etc.

While most of you know that I tend to gravitate towards OPS+ and wRC+, I decided to use wOBA as my total offensive metric for this analysis. Given that Exit Velocity is measured by Baseball Savant (Statcast), I thought it made the most sense to use a metric that is also calculated by Baseball Savant, just so that we are making apples-to-apples comparisons. In spot-checking my numbers, I want all of you to know that OPS+ and wRC+ were both closely aligned with the numbers you will see quoted by wOBA for the 2021 season.

I chose 11 players to analyze for the purposes of this exercise. The majority of the players I chose were guys that we expected would be counted on for significant offensive contributions prior to the start of the 2021 season. Conspicuously absent from that core crop of players is Aaron Hicks and Clint Frazier. I am reasonably certain that neither player played a statistically significant sample size of games healthy during the 2021 season. I did include Miguel Andujar in this analysis, because it appears that he was healthy prior to having his wrist issues flare up after getting sent down to the minor leagues.

The second crop of players are major additions acquired at the trade deadline, comprised of Anthony Rizzo and Joey Gallo. For the sake of sample size, I included their numbers for their full season performances, not just their Yankee at-bats.

Here is the raw data collected for each of the players included in this analysis:

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Exit Velocity vs. wOBA – 2021 New York Yankees (Click to Enlarge)

What follows is a chart that identifies the correlation between Exit Velocity and wOBA that I generated using statistics collected by Statcast:

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Exit Velocity vs. wOBA – 2021 New York Yankees (Click to Enlarge)

There is a lot to digest here. First off, it should be clear that very few Yankees produced above-average offensive value this season. Judge and Stanton were elite offensive threats, while Rizzo and Gallo were above-average, though it must be noted that both compiled the majority of their offensive value with their previous teams, not the Yankees.

Most importantly though, you should note a figure that notes that R2=0.8982. R2 is otherwise referred to as the coefficient of determination, which is a statistical measure of the proportion of the variation in the dependent variable that is predictable from the independent variable. In this case, we want to understand how closely Exit Velocity is correlated with total offensive value. An R2 of 1 would mean a perfect correlation (which is almost impossible to achieve), while 0 would be almost no correlation. By almost any definition, we see that Exit Velocity was very strongly correlated to wOBA on the 2021 New York Yankees.

Rather than sit here and toot my own horn for my deference to the Yankee front office and analysts though, I’m far more interested in the outliers to this chart. Here, we see that LeMahieu, Stanton, Sanchez, Urshela, and Andujar all fall well beneath the trendline generated. The reason for this reality should be one of the great questions of the 2021-2022 offseason, particularly now that the Yankees have signaled that they are moving in a different offensive direction.

Launch Angle and Total Offensive Value

The obvious next step for me after seeing the Exit Velocity data was to determine whether or not the correlation between Launch Angle and total offensive value would give me any clues.

Without further ado, here’s the raw data:

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Launch Angle vs. wOBA – 2021 New York Yankees (Click to Enlarge)

And here’s that data synthesized and analyzed:

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Launch Angle vs. wOBA – 2021 New York Yankees (Click to Enlarge)

Here, you’ll note that we don’t see a nice, linear trendline like we did for Exit Velocity. That is to be expected. 0-10 degrees of launch angle is defined as a ground ball; 10-20 degrees is defined as a line drive; and 20+ is defined as a fly ball. Logically, we would expect that players who hit ground balls would have less offensive value than players that hit line drives or fly balls. Likewise, most of us would likely hypothesize that relative degrees of line drives and fly balls would be more advantageous than others. For that reason, I chose to trend this data set with a polynomial trendline, which recognizes that trendlines can have multiple “humps.” I could have manipulated this data set trendline by artificially including more “humps,” but I stuck with 3, because that’s all I saw looking at the data.

Note that R2 is almost exactly 0.3, which means there is only some correlation between Launch Angle and total offensive value on the 2021 Yankees, bordering on a weak correlation. The reason for this is that there are multiple outliers in this data set, and Joey Gallo specifically skews the data significantly. However, the outliers show us a lot.

Gary Sanchez’s Launch Angle is almost exactly beneath the second-lowest trough of the trendline, showing us that despite his solid Exit Velocity, his Launch Angle is likely too high to produce even expected results for his numbers. Urshela, LeMahieu, and Andujar are all at the lowest points along the Launch Angle trendline, which illuminates the precise reason for their inability to perform at the level their Exit Velocity suggests. Lastly, while Stanton overperformed relative to his expected results vis-à-vis his Launch Angle, we can see that he significantly underperformed Judge, who’s underlying numbers are very similar, save for the fact that Stanton’s average Launch Angle barely meets the threshold for line drives, while Judge clears that definition by a significant margin (10.3 degrees vs. 11.6 degrees).

In short, Launch Angle by itself does not tell the story of the Yankees’ 2021 offense, but in combination with Exit Velocity, it tells us a lot.

Conclusion

There is little more to say but that Exit Velocity and Launch Angle matter, and the correlation between Exit Velocity and total offensive performance remains strong, at least as far as the 2021 Yankees were concerned. The unanswered question is whether or not adherence to increasing Launch Angle as a swing philosophy actually negatively impacted Exit Velocity and Launch Angle for some players. That is one of the chief remaining topics that prospective hitting coaches will need to discuss with the Yankee front office this offseason.

However, it can no longer be said that Exit Velocity and Launch Angle don’t matter. On that point, the numbers from the 2021 Yankees’ regular season are clear.