Like many different nerds, I’ve devoted loads of time to slicing and dicing Baseball Savant’s new bat monitoring information over the previous couple of weeks. And like many different nerds, I’m not completely certain how we’ll find yourself utilizing this wealth of latest data. Extra time, extra information, and extra mind energy is required to wring out no matter sweeping new truths it could maintain. I’m going to write down about bat monitoring information in a extra centered manner subsequent week. There are a pair issues I feel are actually attention-grabbing; not essentially new data, however ways in which bat monitoring information may give us onerous numbers for issues that we’ve already realized. On this article, I’ll be a bit extra scattershot. I’d identical to to take you thru how I’ve processed all the data that has come out over the previous couple of weeks.
First off, bat monitoring will give us new stats that stabilize extra rapidly 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 greater predictor of general 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 information from the primary week of bat monitoring, April 3 to April 9, and in contrast it to every participant’s general numbers this season. I eradicated any participant with fewer than 5 plate appearances in the course of the first week or fewer than 100 PA throughout the complete 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 price higher than first-week hard-hit price (R = .66 for swing velocity, in comparison with R = .46 for hard-hit price). If, after the primary week, you wish to know who’s going to hit the ball onerous for the remainder of the season, don’t take a look at exit velocity. Have a look at swing velocity:
That stated, I’m not optimistic that this specific manner of bat monitoring information will assist anybody. We’re most likely breaking issues down too finely right here. In any case, swing velocity doesn’t have that sturdy a correlation to general 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 price (R = .21 for each). It may inform us sooner how onerous a participant is able to hitting the ball, nevertheless it’s not any faster at telling us how properly they will hit.
Second, I’ve heard good individuals say that this information may forestall accidents. If fatigue, tightness, or tenderness is conserving you from swinging as onerous as you usually would, a watchful analyst may spot it within the numbers and prescribe relaxation earlier than you damage your self. Whereas this makes a certain quantity of sense, I’m skeptical for now. Individuals have been making an attempt to do the identical factor with pitchers for years, monitoring stride size, extension, launch level, velocity, spin price, 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 current 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 bought injured than that they had been earlier within the season.
To date, my greatest takeaway is an apparent one: Bat monitoring may be very difficult. There are such a lot of elements that have an effect on swing velocity and size, and in the event you’re making an attempt to study something, you’ll want to choose your variables very, very fastidiously to be sure to’re evaluating apples to apples. If you wish to analyze swing velocity, you’ll want to just remember to’re accounting for pitch sort. As Ben Clemens has mentioned, sooner pitches elicit slower swings. In fact, swing velocity can be correlated with swing size, and swing size is correlated with location, and placement is correlated with pitch sort, and now we’re again the place we began. For the reason that candy spot of the bat typically begins out someplace above and behind the batter’s again shoulder, it has to journey a higher distance to achieve a slider low and away than a fastball over the center. If you happen to’re swinging at an inside pitch, you’re extra more likely to meet the ball out in entrance, which implies an extended swing. So a participant who chases too many breaking balls is more likely to get dinged for a protracted swing, as is a right-handed Astro who makes a dwelling pulling balls into the Crawford Bins. A kind of is a foul factor, and a kind of is a part of the rationale that Jose Altuve and Alex Bregman are perennial All-Stars.
Right here’s an instance of the battle to discover a consultant pattern. Whereas smarter individuals had been determining the issues I simply informed you, I used to be questioning concerning the power of the connection between swing size and the peak of the batter. In any case, there’s a purpose we anticipate larger gamers with longer levers to hit for extra energy. If you happen to look at Baseball Savant’s essential bat monitoring leaderboard, you’ll see that Oneil Cruz has one of many longer swings within the sport, which isn’t shocking since he’s one of many longer individuals within the sport. Nevertheless, in the event 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 minimize our pattern manner down, however we’re doing our greatest to regulate for the kind, velocity, and placement of the pitch, in addition to the depth of contact. If we give attention to 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 specific break up. Nevertheless, this is probably not the appropriate manner to have 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 any case, 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 appeared 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.
Regardless of how I sliced it, I tended to seek out that peak and swing size had a correlation coefficient between .24 and .35. Nonetheless, as with so lots of my deep dives into bat monitoring information, I’m not fully certain the best way to make all the elements mix right into a cohesive entire. On this instance, it made loads of sense to look solely at whiffs, however on the similar time, it appeared ludicrous to guage a participant’s swing velocity, which exhibits how a lot harm they will do on contact, by throwing out all of the swings the place they really made contact!
I believe that bat monitoring might be utilized in one specific manner 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 understand. They’ll now be capable of level to a selected quantity. Let’s say you’re the Rays and also you need Garrett Cleavinger to throw his four-seamer extra usually. He may be extra doubtless to purchase in in the event 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 realizing that batters can’t even get swing off in opposition to a pitch may be simply as sturdy a motivator.
As I stated on the high, these are simply my first takeaways as I type by the information 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 hold digging.
