Photo: Al Bello (Getty)

Exit velocity has become the bugbear of baseball’s anti–“super nerds” crowd. For them, the relatively recent ability to measure how hard a ball comes off a bat is a symbol of everything wrong with modern baseball analysis: a quantification of something that doesn’t need to be quantified; a number that tells you what your eyes see anyway; a poor substitute for actual scouting. It is, of course, all of these things and none of them.

It is a datum in a sport that runs on data, and that alone gives it value. But it has little value by itself other than as a comparison tool across hitters. An imperfect but useful equivalent—and one that no one doubts the worth of—is pitch speed. If you know a pitcher can throw 100 MPH, what does that tell you? He will tend to be effective at getting batters out, but you can’t know that for sure from the numbers—they have to be combined with other things, like movement and pitch selection, just as exit velocity is itself meaningless as a predictor of anything unless taken into account with things like launch angle and bat speed and pitch identification. Some of this stuff can be quantified, some can’t, and the things that can all influence each other in subtle ways that make any isolated measurement an incomplete story. But no one would ever deride radar gun readouts by saying they’re a poor substitute for seeing with your own eyes that a pitcher throws hard. Because you cannot watch every pitcher’s every pitch or every batter’s every swing, but you can look up their stats.

Here is a clever FiveThirtyEight chart that shows the intersection of exit velocity and launch angle and what tends to happen to a baseball. With a large enough sample size on a hitter, and given only those two measurements, you can construct a reasonably effective model of his tendencies. And that’s all baseball statistics and scouting are really about, fundamentally: odds and tendencies. Exit velocity is no holy grail, and it’s also not meaningless. It’s another number in a sport where the analysis thrives on seeing what the many types of numbers can mean.

And like with any number, it can be pretty cool to see a record broken. Giancarlo Stanton, in Thursday’s 7-3 win over the Rangers, chalked up the hardest-hit home run since StatCast began measuring exit velocity in 2015. The ball came off his bat at 121.7 MPH:

Exit velocity is very clearly no fluke; Stanton and Yankees teammate Aaron Judge now own the 13 hardest-hit home runs of the StatCast era.


“When you get all of it, it’s pretty much one feeling,” Stanton said. “I can’t tell you that I know exactly what the miles per hour is.”And no, you didn’t need exit velocity to know he hit that ball really hard. You saw with your own eyes, or perhaps heard with your ears—Yankees radio guy John Sterling stumbled over his usual home run call because the ball got out of the ballpark just too quickly. But you did click on this blog to see what the hardest-hit home run looked like, so you had at least some curiosity.

Did you get anything from knowing this was an exit velocity record that you wouldn’t have gotten from simply watching Stanton hit the dick off a baseball? That’s a question for you to answer for yourself. But I think it’s good to know things.