What you need to know about Statcast bat tracking

Early returns indicate Julio Rodríguez has elite swing speed

July 14th, 2022

One hundred years ago, Babe Ruth was redefining how baseball was played, and understood. In 1920, Prof. A.L. Hodges, “the Well-Known Physicist,” wrote Ruth had “a 44 Horse-Power Swing Which Shoots the Ball Skyward at Six Miles a Minute,” a fascinating attempt at a proto-Statcast. The next year, a pair of Columbia scientists strapped the Great Bambino into all sorts of tubes and machines in an attempt to break down the ways in which his body moved and reacted, hoping to find how he managed all those swats the sultan was known for.

In 2022, we don’t have Babe Ruth, but we also don’t use horsepower to measure much outside of engines. Instead, we have Aaron Judge, and Mike Trout, and directly tracked Statcast measurements for the types of things Prof. Hodges and friends could only have dreamed of a century ago.

But what we haven’t had is much in-game information on how the bat itself moves, swings, or makes contact, how fast or slow, at what angle. We know a whole lot about how the ball moves coming toward the bat and what the ball does when it leaves the bat. We know plenty about how the bat moves in controlled experiments, or lower-level games, or hitting factories. But real data from regular season Major League games? There just hasn't been a whole lot to look at, unless you work for a team.

Earlier this year, that began to change. Tracking turned on. Data began to flow. And the high-level takeaways, nascent as they are, seem fascinating.

Enjoy the earliest impressions, with hopefully more to come.

1) So what’s all this then?

Technology to track the speed and path of bats is not exactly new; teams and swing coaches have been investing in bat sensors and other technology for years, primarily used in practice or laboratory or other non-game settings. It’s a near certainty that some teams have their own internal measures of bat speed; as we said, physicists have been working out optimal swing paths and ways to calculate swing speed for decades. In 2015, to pick one example of many, Dr. Alan Nathan went deep into the physics of it all. This is a new way to attack a very old question.

What’s different, then, is that this is in-game tracking, collected from real 2022 Major League Baseball action. It doesn’t require reverse engineering from exit velocity; it doesn’t require any gear on the bat. It just requires playing in a ballpark where the hardware is installed, just like any other metric you’re familiar with.

When Jazz Chisholm Jr., for example, mashed a Luis García four-seamer into right-center field for a two-run homer on June 10, you could have easily called up Baseball Savant and seen that the ball came off his bat at 100.6 mph and went a projected 399 feet. Now, you can also know that his swing was 94.1 mph (Sort of. We’ll get back to that.) You can know it was hit 4.5 inches from the end of the bat, that he squared it up 70% successfully, that it was hit .6 inches above the center line of the bat. There's so much more to know than we already did. There always is.

2) How is this tracked?

By the Hawk-Eye cameras that power Statcast, like most everything else. Earlier this season, in two ballparks -- Minute Maid Park and Dodger Stadium -- an additional four high-frame-rate cameras were installed, capable of capturing video at 300 frames per second. (The pitch-tracking cameras are at 100 f/s, while player tracking is 50 f/s, so this is considerably higher quality, necessary for something so small moving so quickly.)

Consider all this, really, a dry run. It’s a way to test the functionality of the value of the high-frame-rate cameras, to ensure that the data makes sense, to find out if it provides value both in player development and storytelling, before expanding to additional parks.

Since it’s in so few parks, and for less than half a season, there are not full leaderboards out there to share, yet. But rather than wait for years of data, we thought we’d let you know that it’s there, to share what’s been learned, while being upfront about the fact the small sample size here provides more than a small grain of salt.

3) What data set are we looking at?

As we said, we’re only looking at data from Minute Maid Park and Dodger Stadium, since mid-May through July 10. That does mean it’s largely Astros and Dodgers, but not entirely; plenty of visiting teams have gone through those two places.

For the moment, we’re just looking at swings where contact was made -- whiff swings are valuable, and possible, but they’re not part of the current data set we’re working with -- and we’ve set a floor of 50 mph swing speed, which is just about the minimum you can have for a “real” swing, i.e., cutting out checked swings.

That gives us nearly 2,000 swings from more than 160 players. It is but a fraction of the entire season to date. It should be enough to take an initial look at.

4) How do you define bat speed?

You’d think this would be the easy part, right? It is not.

Remember when we said Chisholm’s June 10 home run had a swing speed of 94.1 mph (“sort of”)? That’s because different parts of the bat move at different speeds; the end of the bat has a lot longer to go than the handle does, in the same amount of time. You could say the head of his bat was traveling at 113 mph, which it was. You could say the point of the bat that made impact was going 98.6 mph.

Or you could say that the "sweetspot," the part where players are almost always actually trying to make contact, was going 94.1 mph. That or something near it is generally the industry standard -- Blast Motion, one of the leading wearable solutions, uses 6 inches exactly, for example -- and it’s a point that’s easily understood for casual fans, so that’s what we’ll use here: 6 inches from the head.

It’s almost like asking whether you should measure the velocity of a pitch out of the hand (as is done now) or at a set point (as has been done in the past) or at the time it gets to the plate. All are valid, and there are many choices, but for simplicity’s sake, you might just have to pick one. The sweetspot, then, it is.

5) What makes a good swing?

Bat speed matters, greatly. If you can’t swing above, say, 70 mph on a regular basis, you’re probably not a Major Leaguer. That’s especially true if you want to hit a home run; of the more than 80 dingers in our set, the average sweetspot speed was 85.5 mph, and only one was below 75 mph. (Singles are 79.5 mph, on average; doubles and triples, 82.8 mph.)

Or, as Conner Watson, a hitting trainer at Driveline Baseball aptly tweeted: “Move the bat faster. Best chance of getting paid to play this game.” After all, as he also shared, one study showed that an extra mph of bat speed at the same launch angle can get you 7 feet of extra distance.

Based on what we’ve observed, the average swing is about 80 mph.

But of course, there’s more to hitting than just swinging hard, in the same way that a pitcher who throws 100 mph still needs to throw strikes. You also won’t likely be surprised to know that there are massive differences in observed success based on whether you square up a ball … or don’t. That's what this image is showing you, without even worrying about bat speed. Want to do damage? Square up the ball.

Put another way: Every single home run we have tracked here hit the bat between 3 inches and 9.7 inches from the head. You can't homer off the end of the bat, and you can't homer off the handle.

Put yet another way: If you sort all of the batted balls, starting by impact at the head of the bat and working down, we had to go down through 184 poorly hit balls before we found our first hard-hit one (95+ mph of exit velocity). From the other end, working from closest to the handle up, it’s 158 poorly hit balls.

Hard-hit rate by location on the bat

Head to 2 inches: 2%
2 to 4 inches: 42%
5 to 9 inches: 65%
10 inches to handle: 2%

At its most simplistic: the way to make the ball fly the fastest (i.e., exit velocity) is overwhelmingly a combination of bat speed -- how fast are you swinging a bat that weighs how much -- and how effectively the bat contacts the ball (i.e., where on the bat was impact?). Additionally, to a far lesser but non-zero extent, pitch speed has some input as well.

6) Who swings the hardest?

This is what you came for, right?

With a minimum of three batted balls in our two parks … you will absolutely not be disappointed to know that based on our data, it is Seattle’s rookie superstar Julio Rodríguez, at 96.2 mph. Let’s repeat our caveat: This is based on the data we have, which is only based on the players who have played in Houston or Los Angeles over the last two months. This means we’re missing some players entirely, and don’t have enough data on others. We have one game for Giancarlo Stanton. Was he at his best that day? Let’s not pretend we know.

That said … this is a list of hitters you mostly want to be on.

For the most part, these names all makes sense. Rodríguez, Robert, Alvarez, Witt, and Chisholm are among the game’s more celebrated young talents. Chisholm, in particular, gained fame last year for turning 100 mph pitches into home runs, a feat that absolutely requires elite bat speed. (Given their youth, this also makes us wonder how much bat speed will age as other skills do, though we don't have enough data to say yet.)

You may not know Sánchez as well, but he did hit the third-longest home run Statcast has ever tracked earlier this year. Stanton, Reyes, Machado, Cron, Alonso, and Wisdom are all known power threats. Maybe we’ve learned something about Marlins catcher Fortes, who had a .584 slugging percentage in his first 101 plate appearances, and maybe you remember Castro was the first player to have his first five hits all go for home runs, last year.

Now: Are three contacts enough of a minimum? Ideally, we’d have more. Then again, when the top of this list has all of these names … and the bottom five are light-hitting Adam Frazier, Steven Kwan, Luke Williams, Patrick Mazeika, and Andrelton Simmons (69.1 mph swing speed in tracked games, and a .187 slugging overall) … it’s clear that even in this limited sample there’s some real signal here.

Here’s the fastest contact we have, Pete Alonso getting up to 107.8 mph of sweetspot speed on a blast off Houston’s José Urquidy. It sure looks the part.

Average, though, can have its flaws, so in the same way we often prefer hard-hit rate (balls hit over 95 mph of exit velocity) over average exit velocity, we can look at a “hard-swing rate” or how often are swings seen over 85 mph? Rodríguez would be one of five players with a perfect 100% rate. Unsurprisingly, Robert, Machado, and Reyes are in that group. More entertainingly, a name that wasn't on our leaderboard above joins: Mike Trout. It would just be like Trout, anyway, to excel in something that requires consistency.

7) What about just the Dodgers and Astros?

We keep mentioning the limitations of having only two parks online, so what if we just look at the players who call those parks home? We have, for example, 67 contacts from Jose Altuve and 70 from Freddie Freeman.

It should not be surprising to see Yordan Alvarez rate well here.

It might be surprising to see Trayce Thompson there, though A) his problems are generally more about “making contact” than “making good contact,” and B) he’s had so many more hard-hit balls at Dodger Stadium this year than anywhere else that this might just be his good fortune of hitting where the tracking is.

There’s obviously not a 1:1 correlation between swing speed and success here, which shows the importance of making contact and squaring up the contact you make and doing all that while swinging hard. More importantly, without multiple years of data, we’re not quite certain if it’s concerning that Justin Turner -- who turns 38 in November and has his lowest slugging percentage since 2013 -- rates this poorly, or if that's never been a skill he had in the first place.

8) What about the path of the swing?

If you’ve ever seen, say, Joey Gallo and Luis Arraez swing, you know that not all swings take the same route. There’s the massive uppercut swing, and the level swing, or even, for many years but less popularly so now, the “swing down” swing. This is the attack angle of the swing -- you know, the kind of stuff Ted Williams was talking about more than 50 years ago.

We can look at that, too. Back in 2018, Driveline noted that the attack angles of the hitters they trained fell between 4 and 21 degrees (with 0 degrees being horizontal to the ground), so we were pleased to find that our Major Leaguers came out with similar numbers, with the range going from an average of 0 degrees at the lowest to exactly the 21 degrees they indicated at the highest. (The average is 11 degrees.)

We were even more pleased by the names. The flattest average swing, that 0 degrees we just noted? It’s Cleveland’s Steven Kwan, who offers little power (one home run in 300 plate appearances this year) but has the lowest swing-and-miss rate in baseball. (Just behind him: Brandon Nimmo and Ke’Bryan Hayes.)

The most uppercut average swing, that +21 degrees mark? It’s Houston’s Jose Altuve, who for years has been generating far more power than his 5-foot-6 frame would suggest. (Just behind him: Max Muncy and Kole Calhoun.)

To pick out two swings to compare, you can really see the difference. First, take a look at Luke Voit putting a massive uppercut swing (31 degrees) on a blasted home run on July 2.

Then, see the difference when Will Smith puts an extremely level swing (1 degree) on a groundout the next day.

It’s not entirely about attack angle, of course. Voit swung the bat at 91.5 mph, and made contact 0.8 inches above the center line of the barrel, all nearly perfect contact. Smith swung only 76.2 mph and made contact 0.2 inches below the center line. You’d rather be Voit, even without the high angle. But you’d especially rather be Voit given what else we know.

In fact, if you take all of the swings we have -- again, just contacts for now, with swing-and-misses not yet included -- and sort them from highest attack angle to lowest, we can split them into four groups, and find some interesting patterns.

As you might expect, the uppercut swings lead to considerably more power and distance but fewer non-homer hits (i.e., a low BABIP). The flat swings do well for batting average, but just about no power at all.

Again, we’re missing swing-and-misses here, and we’re guessing the uppercut swings fare terribly there as compared to the flat ones.

9) What’s next?

As we said above, our initial look was just at swings that made contact with the ball, not misses, which means there's an incredible amount of additional information to get to -- think about who misses pitches by the most or least, or above the bat or below the bat. (For that matter, think about all of this from the pitcher's POV, as well.) It could allow better looks at where max speed is coming from for different hitters, who squares up the ball the best at that time, who's successful out front or staying back. Or, as in the Ted Williams example above: Who does the best job of tailoring their swing path to the incoming pitch path?

It is, hopefully, the first step into the missing key of making great contact. For hitters, the bat is the single most important piece of equipment they have. We've been without nearly enough information on it, at least in real games. You can see why it might be so useful to know what's actually happening with it.

Many thanks to MLB.com's Tom Tango, Graham Goldbeck, Shanna Shi, Clay Nunnally, Ben Jedlovec, Brandon Nickell, Bailie Brown, Jack Olszewski, and assuredly many others for assistance in collecting and understanding this data.