Like many different nerds, I’ve devoted quite a lot of time to slicing and dicing Baseball Savant’s new bat monitoring knowledge over the previous few weeks. And like many different nerds, I’m not fully certain how we’ll find yourself utilizing this wealth of recent info. Extra time, extra knowledge, and extra mind energy is required to wring out no matter sweeping new truths it might maintain. I’m going to jot down about bat monitoring knowledge in a extra targeted approach subsequent week. There are a pair issues I believe are actually fascinating; not essentially new info, however ways in which bat monitoring knowledge can provide us laborious numbers for issues that we’ve already discovered. On this article, I’ll be a bit extra scattershot. I’d similar to to take you thru how I’ve processed all the knowledge that has come out over the previous few weeks.
First off, bat monitoring will give us new stats that stabilize extra shortly than current ones, as that’s how granular metrics that separate underlying expertise from outcomes are inclined to work. In smaller samples, exit velocity turned out to be a higher predictor of total batting efficiency than wRC+ or wOBA. Now now we have swing velocity, which in smaller samples seems to be a greater predictor of exit velocity. To wit, I pulled knowledge from the primary week of bat monitoring, April 3 to April 9, and in contrast it to every participant’s total numbers this season. I eradicated any participant with fewer than 5 plate appearances through the first week or fewer than 100 PA throughout all the season, which left me with a pattern of 295 gamers. It was no contest. Full-season exit velocity had a a lot stronger correlation to first-week swing velocity (R = .60) than it did to first-week exit velocity (R = .40). It additionally predicted full-season hard-hit fee higher than first-week hard-hit fee (R = .66 for swing velocity, in comparison with R = .46 for hard-hit fee). If, after the primary week, you wish to know who’s going to hit the ball laborious for the remainder of the season, don’t take a look at exit velocity. Take a look at swing velocity:
That mentioned, I’m not optimistic that this explicit approach of bat monitoring knowledge will assist anybody. We’re most likely breaking issues down too finely right here. In spite of everything, swing velocity doesn’t have that robust a correlation to total success on the plate, a lot decrease than exit velocity. If we return to our first-week stats, swing velocity has a barely decrease correlation (R = .19) to full-season wOBA than exit velocity or hard-hit fee (R = .21 for each). It will probably inform us sooner how laborious a participant is able to hitting the ball, however it’s not any faster at telling us how nicely they’ll hit.
Second, I’ve heard sensible individuals say that this knowledge might forestall accidents. If fatigue, tightness, or tenderness is protecting you from swinging as laborious as you usually would, a watchful analyst might spot it within the numbers and prescribe relaxation earlier than you harm your self. Whereas this makes a certain quantity of sense, I’m skeptical for now. Folks have been making an attempt to do the identical factor with pitchers for years, monitoring stride size, extension, launch level, velocity, spin fee, and break for indications of fatigue or compensation. To my data, nobody has cracked that code but. For some fast anecdotal analysis, I checked two distinguished gamers with latest accidents: Ronald Acuña Jr. and Steven Kwan. Not that this implies something, particularly with two decrease physique accidents, however each Acuña and Kwan had been truly swinging barely tougher in opposition to four-seamers within the week earlier than they received injured than they’d been earlier within the season.
Thus far, my largest takeaway is an apparent one: Bat monitoring could be very difficult. There are such a lot of elements that have an effect on swing velocity and size, and in case you’re making an attempt to study something, you’ll want to choose your variables very, very rigorously to be sure you’re evaluating apples to apples. If you wish to analyze swing velocity, you’ll want to just be sure you’re accounting for pitch kind. As Ben Clemens has mentioned, quicker pitches elicit slower swings. After all, swing velocity can be correlated with swing size, and swing size is correlated with location, and placement is correlated with pitch kind, and now we’re again the place we began. Because the candy spot of the bat typically begins out someplace above and behind the batter’s again shoulder, it has to journey a larger distance to succeed in a slider low and away than a fastball over the center. For those who’re swinging at an inside pitch, you’re extra more likely to meet the ball out in entrance, which implies a longer swing. So a participant who chases too many breaking balls is more likely to get dinged for an extended swing, as is a right-handed Astro who makes a residing pulling balls into the Crawford Packing containers. A kind of is a foul factor, and a type of is a part of the explanation that Jose Altuve and Alex Bregman are perennial All-Stars.
Right here’s an instance of the wrestle to discover a consultant pattern. Whereas smarter individuals had been determining the issues I simply advised you, I used to be questioning concerning the energy of the connection between swing size and the peak of the batter. In spite of everything, there’s a motive we count on larger gamers with longer levers to hit for extra energy. For those who look at Baseball Savant’s major bat monitoring leaderboard, you’ll see that Oneil Cruz has one of many longer swings within the recreation, which isn’t stunning since he’s one of many longer individuals within the recreation. Nevertheless, in case you drill all the way down to get a extra consultant pattern, issues change.
Let’s say you look solely at aggressive swings on middle-middle fastballs that resulted in balls hit straightaway. We’ve lower our pattern approach down, however we’re doing our greatest to manage for the sort, velocity, and placement of the pitch, in addition to the depth of contact. If we deal with these pitches, it seems that when he’s not flailing at breaking balls, Cruz has a surprisingly quick swing, under the massive league common on this explicit cut up. Nevertheless, this is probably not the fitting approach to take a look at issues. Perhaps Cruz’s numbers look too rosy as soon as we’ve thrown out his many, many whiffs. Perhaps we must always solely be whiffs. In spite of everything, if we simply take a look at whiffs, we don’t have to fret about accounting for depth of contact, as a result of there isn’t any contact. That’s an enormous variable eradicated. After I seemed simply at whiffs on middle-middle fastballs, Cruz’s swing size was not under common, though it was nonetheless comparatively quick for such a tall participant.
Irrespective of how I sliced it, I tended to search out that peak and swing size had a correlation coefficient between .24 and .35. Nonetheless, as with so a lot of my deep dives into bat monitoring knowledge, I’m not utterly certain find out how to make the entire elements mix right into a cohesive complete. On this instance, it made quite a lot of sense to look solely at whiffs, however on the similar time, it appeared ludicrous to evaluate a participant’s swing velocity, which reveals how a lot injury they’ll do on contact, by throwing out all of the swings the place they really made contact!
I believe that bat monitoring shall be utilized in one explicit approach in a short time. We’ve all learn articles about groups telling their pitchers to belief a sure pitch as a result of it’s nastier than they notice. They’ll now have the ability to level to a selected quantity. Let’s say you’re the Rays and also you need Garrett Cleavinger to throw his four-seamer extra typically. He may be extra probably to purchase in in case you inform him that batters are swinging three ticks softer in opposition to it than they’re in opposition to his cutter and his sinker. Whiffs are nice, however understanding that batters can’t even get an excellent swing off in opposition to a pitch may be simply as robust a motivator.
As I mentioned on the prime, these are simply my first takeaways as I kind by way of the info and course of what smarter baseball analysts have written on the subject. I’ll be again with extra subsequent week, and within the meantime, I’ll preserve digging.