15 April 2016

Yovani Gallardo Has Two Sliders

During his first start for the Orioles on April 11, Gallardo threw 96 pitches - 67 of which PITCHf/x determined to be sliders. A look at the movement of his 96 pitches (with gravity - this is what the batter saw) shows two very distinct clusters of sliders. One looks the way you might expect a slider to look: dropping lower in the zone, traveling from left to right across the plate. The other cluster stayed up, dropping about 10 inches with the help of Mother Nature, and never actually slid. Instead, the second bunch of sliders stayed straight. They look the way you would expect a fastball to look.

PITCHf/x classifications are determined today by algorithm, although it has been done by hand in the past. It's certainly possible that these are simple misclassifications as a result of that estimation model. Gallardo's fastball was only thrown about 4 miles per hour faster on average than his slider - a major difference, but one that can easily be spanned by arm fatigue. Gallardo's fastest slider on April 11 was thrown at 87.5 miles per hour. It's entirely conceivable that an algorithm could label an 87.5 mile per hour slider that doesn't slide as an 88 mile per hour fastball.

At the same time, Gallardo has a short bit of a history with these two types of sliders. The vast majority of Gallardo's straight sliders is from 2015 onward, indicating that he could have added a slider with a different spin and a different movement path to his arsenal. According to PITCHf/x, Gallardo is also increasing the number of sliders he throws every year. If there were a sudden spike in slider usage, I might be more apt to consider it a fluke pointing to an issue in the algorithm's ability to classify Gallardo's pitches.

This leaves three possibilities (or some combination thereof, I suppose) to explain why PITCHf/x thinks Gallardo is throwing so many sliders, and in two distinct types. The first is that PITCHf/x is simply misclassifying Gallardo's fastballs as sliders for some reason and with some regularity. The second is that Gallardo actually did throw an obscene amount of sliders on April 11 and that they have always been more common for him than fastballs, he just isn't getting the break on them the way we would want to see. The final possibility is that Gallardo actually has two sliders that he throws in two different ways, on purpose, for different effect.

John Walsh at the Hardball Times put together a helpful pitch identification primer in 2009, in which he describes sliders as generally falling between fastballs and curveballs in terms of both speed and movement. He also identifies sliders that don't have any horizontal spin or break at all, pitches with essentially no movement. Here's how he describes the specific subset of sliders that we are possibly seeing from Gallardo:
[I]f the axis of spin is aligned with the direction of the pitch (like a football toss, or a … gyroball), there will be no break. I believe this is what we are seeing when we see a pitch with no movement. I wouldn’t call these gyroballs, by the way. Or maybe I should—in any case, a number of different pitchers throw sliders that fit the description, and I don’t believe it’s anything new.

While it's pretty cool to throw the same pitch two ways for two different effects (which, uh, might make them two pitches?) - if that is the case - it hasn't necessarily helped Gallardo. His batting average allowed on decisive sliders - ones that ended the plate appearance - from 2012 through September 2015 is 0.239, while his slugging percentage on decisive sliders is 0.370. When it's broken into the two categories of sliders, it's clear that one is more helpful than the other.

Pitch Type
Traditional Slider
Straight Slider

Pitches in red are what I'm calling Straight Sliders.
Notice that Gallardo hasn't thrown what I called a straight slider very often over his career. However, 49 of those came in 2015 alone, and he looks to have thrown about 20 in his first 2016 start as well. While the straight slider hasn't burned Gallardo for extra bases yet, it's worth keeping an eye on. If he means to get movement across the plate, it's a major issue that Gallardo is suddenly less and less capable of doing so. If he is using a straight slider as a pseudo-fastball for some reason, batters seem able to hit it pretty well. Gallardo's next few starts for the O's may shed more light on whether he's actually throwing this many sliders and whether he's throwing straight ones on purpose. If the latter is true, we're probably in the process of watching Gallardo reinvent his pitch arsenal, and arguably to one that gives up more hits.


Matt Perez said...


The problem is that there is only a small sample size for the straight sliders and therefore it's hard to tell what will happen. But I completely disagree with you about the implications.

Pitchers are largely unable to control batting average. There are probably exceptions to the rule, but I'm not ready to concede based on a small sample that Gallardo's straight slider is one of those few exceptions. What pitchers DO control is slugging percentage.

It's not that bad pitches turn into hits more often then good pitches. It's that bad pitches turn into home runs and good pitches turn into fluky singles. If so, it's far more likely that the straight slider is better then the regular slider. After all, batters are typically getting weak contact against the straight slider and strong contact against the normal slider.

Of course, this analysis only looks at balls in play and not what he does against balls not in play. I'd have to see that before making any other judgements.

Jeff Long said...

Ok, here's my theory. I went back and watched the game on MLB.tv to see what Wieters was calling. I think fundamentally you're asking a question of: "What makes a pitch, a pitch?". Or, more clearly: "What makes a slider, a slider?" That is, there are a few things that can differentiate pitches. Is it determined by what the catcher calls? By what the pitcher thinks he's throwing? By the grip of the pitch? By arm action at release? By behavior in flight?

All of these are arguably fit for describing what makes a slider, a slider.

In this case, a few things are happening. The relative velocity of the pitch is totally screwing with the Pf/x algorithms. I mean, he's throwing his FB in the 86-88 range, which is why it's struggling between calling it a slider or a fastball. On Brooks, we have it as a mix of sliders, fourseamers, and sinkers. I believe, that the reality is a bit different than either Brooks or MLBAM/Texas Leaguers.

So, I went back and watched the game (read: the 2nd inning). Wieters only called for four distinct pitches (1-Fastball, 2-Slider, 3-Changeup, 4-Curveball). His true slider sits 83-84, and has pretty distinctive movement. To the hitter, his true slider is going to have a red dot (https://xraydelta.files.wordpress.com/.../mariano-rivera...) so it's pretty distinct from a hitter's POV. The other sliders you've analyzed occur, it appears this way to me anyway, when Wieters calls for a "1" or a fastball.

So here's my sense. Back in 2014 I wrote about how Gallardo was pretty adept at tweaking things to make diminishing velocity work (http://www.beyondtheboxscore.com/.../yovani-gallardo...). That's what I'm seeing here. When I was watching the game, something stuck out. Wieters would throw down a "1" and Gallardo would toss a pitch. If it was closer to 86 the pitch would have some glove-side pull, looking almost like a baby cutter. If he really got after it and the offering was up in the 88 range, he'd fly open a bit and the ball would have more arm side run.

I think, at the end of the day ... he's sitting there thinking "Shit. I'm throwing 86-88 right now. I need to put a little cut on this thing so guys don't crush it". Then when he rears back for more velo he loses it. His slider then is a traditional wrist-breaking slider (there are multiple ways to throw a cutter, which is an aside I can get into if you're interested) whereas this baby cutter is simply a grip manipulation on his traditional fastball.

Roger said...

Dudes, Gallardo looks terrible. He may be an Albert Bellian mistake at this point. Fortunately for only two years and not three.

Roger said...

Oh and I just read the story about Gallardo's shoulder discomfort. I guess those damn Orioles physicals are worth something after all. Orioles seem vindicated every time. This may be the best thing to happen for the O's. Gallardo to the DL, Gausman to SP and no one of the other better performers has to go out. They should have dumped Gallardo like they did Balfour. Balfour was never decent again. Kazmir's not looking too good either and I was on that bandwagon.