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 solely positive how we’ll find yourself utilizing this wealth of latest data. 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 write down about bat monitoring knowledge in a extra targeted method subsequent week. There are a pair issues I believe are actually fascinating; not essentially new data, however ways in which bat monitoring knowledge can provide us exhausting numbers for issues that we’ve already discovered. On this article, I’ll be a bit extra scattershot. I’d identical 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 rapidly than present ones, as that’s how granular metrics that separate underlying expertise from outcomes are likely to work. In smaller samples, exit velocity turned out to be a greater predictor of general batting efficiency than wRC+ or wOBA. Now we have now 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 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 whole 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 charge higher than first-week hard-hit charge (R = .66 for swing velocity, in comparison with R = .46 for hard-hit charge). If, after the primary week, you need to know who’s going to hit the ball exhausting for the remainder of the season, don’t have a look at exit velocity. Have a look at swing velocity:
That mentioned, I’m not constructive that this explicit method of bat monitoring knowledge will assist anybody. We’re in all probability breaking issues down too finely right here. In any case, swing velocity doesn’t have that robust 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 charge (R = .21 for each). It might inform us sooner how exhausting a participant is able to hitting the ball, however it’s not any faster at telling us how effectively they’ll hit.
Second, I’ve heard sensible folks say that this knowledge may forestall accidents. If fatigue, tightness, or tenderness is preserving you from swinging as exhausting as you usually would, a watchful analyst may 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 charge, and break for indications of fatigue or compensation. To my information, 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 towards four-seamers within the week earlier than they received injured than they’d been earlier within the season.
Up to now, my largest 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 for those who’re making an attempt to be taught something, it is advisable choose your variables very, very fastidiously to be sure to’re evaluating apples to apples. If you wish to analyze swing velocity, it is advisable just remember to’re accounting for pitch sort. As Ben Clemens has mentioned, quicker pitches elicit slower swings. In fact, swing velocity can also be correlated with swing size, and swing size is correlated with location, and site is correlated with pitch sort, and now we’re again the place we began. Because the candy spot of the bat usually 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. For those who’re swinging at an inside pitch, you’re extra prone to meet the ball out in entrance, which suggests an extended swing. So a participant who chases too many breaking balls is prone 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 nasty factor, and a type of is a part of the rationale 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 folks had been determining the issues I simply instructed you, I used to be questioning in regards to the energy of the connection between swing size and the peak of the batter. In any case, there’s a purpose we count on greater gamers with longer levers to hit for extra energy. For those who 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 stunning since he’s one of many longer folks within the sport. Nonetheless, for those who drill right 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 reduce our pattern method down, however we’re doing our greatest to regulate for the sort, velocity, and site 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 brief swing, beneath the large league common on this explicit break up. Nonetheless, this is probably not the appropriate method 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 should always solely be whiffs. In any case, if we simply have a look at whiffs, we don’t have to fret about accounting for depth of contact, as a result of there isn’t a contact. That’s an enormous variable eradicated. Once I appeared simply at whiffs on middle-middle fastballs, Cruz’s swing size was now not beneath common, though it was nonetheless comparatively brief for such a tall participant.
Irrespective of how I sliced it, I tended to search out that top and swing size had a correlation coefficient between .24 and .35. Nonetheless, as with so lots of my deep dives into bat monitoring knowledge, I’m not utterly positive the way to make all the 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 identical time, it appeared ludicrous to evaluate a participant’s swing velocity, which exhibits how a lot harm they’ll do on contact, by throwing out all of the swings the place they really made contact!
I think that bat monitoring might be utilized in one explicit method 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 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 is likely to be extra probably to purchase in for those who inform him that batters are swinging three ticks softer towards it than they’re towards his cutter and his sinker. Whiffs are nice, however figuring out that batters can’t even get an excellent swing off towards a pitch is likely to be simply as robust a motivator.
As I mentioned on the high, these are simply my first takeaways as I kind via 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 hold digging.
