Nerding Out on Bat Tracking
It has been a good while since we have really nerded out on some baseball numbers… and it just so happens that the folks over at Statcast™ have given us a whole bunch of new numbers to nerd out over. They call it “bat tracking,” and I have no idea what it’s about, but let’s learn about it together, shall we?
If you want a more comprehensive explanation of Bat Tracking—with the added advantage of actual knowledge on the subject—check out our pal Mike Petriello’s breakdown. We’ll lean a bit on Mike’s work here, though our goal is more about figuring out if Bat Tracking can give us fun new insights into baseball.
First: What is bat tracking? I mean, how is it any different from the exit velocity and launch angle numbers that we already get (and, from what I’ve heard via emails, many of you don’t particularly like)?
So, I guess the simplest way to describe it is this: Exit velocity and launch angle and such things focus on the baseball. Bat tracking, as the name suggests, focuses on the bat… and that instant when the bat and ball make contact.
There seem to be four significant measurements:
Bat speed. People have been talking about bat speed pretty much since the dawn of time, but there had never really been an easy way to measure it. Because of the Statcast™ Hawk-eye cameras, they can now get the player’s exact bat speed. By the way, they measure the bat’s sweet-spot speed as it’s making contact; apparently, different parts of the bat go through the zone at different speeds.
Fast swing rate. This is how often a player’s bat goes through the zone at 75 mph or faster (the average bat speed for major leaguers is 71.4 mph).
Squared-up rate. This is how often the player squares up the ball. The way they figure out if a ball is squared up is interesting—they calculate the maximum attainable exit velocity based on bat speed and pitch speed. For example, according to Petriello, if a batter’s bat speed is 66.4 mph and the pitch is 89.1 mph, the absolute fastest possible exit velocity is 100.1 mph. If the actual exit velocity is 80% of that or higher, the baseball is considered squared up.
Swing length. Again, long before Statcast™, people were talking about long swings and short swings. Using technology, they have figured out who has the longest and shortest swings in the game.
OK, so those are the basics. So now, let’s see what sort of fun we can have with the numbers: