It wasn’t so long ago that Tyler Glasnow and Drew Hutchison were battling it out for the Pirates fifth rotation spot, and the Pirates’ brass were expressing, “I wish one of them would just step up and grab it.”
Ultimately, Drew Hutchison more squandered the opportunity than Tyler grabbed the reigns, but nevertheless, Glasnow’s tantalizing presence in the rotation was clearly seen as a boon by many Pittsburgh fans at the time.
Yet, twelve starts and a 7.45 ERA later, it can be a little more difficult remain optimistic as Glasnow was sent back to AAA Indianapolis.
For those who ardently felt Glasnow shouldn’t have joined the rotation to begin with, it had nothing to do with his ability to succeed against minor league hitters as he had clearly dominated them. But on the contrary, it was about Glasnow refining his arsenal and feeling comfortable with a third pitch, so that he could have the best opportunity of being successful (even if the Pirates could use the pitching help now).
While Glasnow clearly has more work to do, his time in the majors this season was more encouraging than the numbers demonstrated; it may seem like a peculiar thing to say given how poorly the results were, but Glasnow did a lot of things that he really needed to do to develop. He just has a lot more work to do, and it’s become clear that being sent to AAA will hopefully give him an opportunity to approach things differently.
For now, I simply want to explore some of those encouraging signs.
In his time with the Pirates last season, Glasnow threw just 11 changeups (under 2 % of his total pitches), relying solely on his fastball and curveball to try attack hitters, and seven of those changeups were in one game, meaning there was even more of an imbalance on most nights.
As would be expected, it proved to be too much of a challenge for Glasnow because he had to rely on location and varying the velocity to keep hitters off-balance the second and third time through the order. He too frequently found himself trying to paint the corners or struggling to harness his stuff as he walked over five batters per nine innings.
During this past February, Tim Williams wrote a piece on the “Evolution of Tyler Glasnow’s Changeup” and noted that Glasnow said the following about his changeup from last season: “It was 92 and didn’t move at all…So if I threw it, it would be a bad fastball. Now we’re playing it off the two-seam too, and it has better movement, so it’s just more comfortable.”
As a result, Glasnow switched the grip on his changeup, which Williams gives a more in-depth look if you haven’t had the opportunity to read it. Anyways, his “new changeup” hasn’t been perfect by any means, but I wanted look how it’s surpassed his off-speed pitch from last season by examining a couple of things.
First, let’s look at the velocity differential between his fastball and changeup from last year and this year.
For a changeup to be effective at “changing-things-up,” it should have a healthy velocity differential between from the fastball. Last year, Glasnow’s average differential was only 4.6 MPH, which was about as bad as it gets and one of the reasons it sometimes ended up as a bad fastball, as characterized by Glasnow. To put in perspective how bad that was, I dove into some numbers prior to this season and found some interesting information:
“16 qualified starting pitchers averaged a harder fastball velocity than Glasnow, and of those 16, the only one who threw a harder changeup was Noah Syndergaard. Thor rightfully should considering he occasionally hits triple digits and regularly throws over 97 MPH, but it’s not promising that Glasnow threw harder changeups than all the rest. It also doesn’t bode well for Glasnow that the only pitcher in the sample remotely close in average differential was Jake Arrieta, with a five-MPH differential.”
While the six mph average differential isn’t an incredible feat either, it is more of a differential than a whole host of other starting pitchers and moves him to a more appropriate place among those hardest-hardest throwing pitchers. Also, this season the changeup has significantly more range to it, falling between 83 mph and just over 92 mph, which adds vastly more utility to the pitch than the 2.7 mph range did last season.
Next, we will turn our attention to the movement on Glasnow’s changeup. Below, you’ll find his four-seamer movement and his changeup movement from last season on the same chart.
Glasnow wasn’t exaggerating with that bad fastball comment because his fastball and changeup literally had the same movement and sometimes the same velocity, which means it essentially was the same pitch.
Now, look at how the new changeup has rectified that situation:
There is distinctly different movement on the changeup than there has been in the past, proving that Glasnow truly is doing something different. I realize that there is still some overlap, but that doesn’t mean he is sinking back into last year’s issues. In an inning where Glasnow is throwing harder or with more movement, it’s natural that the changeup could be harder and have the movement that is sometimes resembles the fastball; Of course, that isn’t always the case, but we’ll reference that later.
Despite all of the that, the changeup has gotten hammered to the tune of a 198 wRC+ that is largely driven by the fact that all of the hits off of the changeup have been for extra bases. Granted, there have only been five hits off of the changeup. Quite honestly, it has a very healthy 17.3% swinging strike rate, which is only one less than Jon Lester’s top ten changeup on the year. The catch is that Glasnow is only getting them to chase 24.3 percent of his changeups, suggesting quite a few are probably obvious balls or wasted pitches.
Last year, Glasnow would have stopped throwing the changeup when it wasn’t working, but this year he has embraced the notion that he needs the pitch if he’s going to be a successful major league starter. The swinging strike rate alone attests to its potential to be a strong piece of his repertoire, but he clearly needs to work on the location and learn how to play it off of the rest of his arsenal more effectively.
But if you recall, the changeup grip alteration was not the only change Glasnow is working with; he now has a two-seamer in the fold.
For an organization that’s been obsessed with their pitchers inducing groundballs, it’s strange that the philosophy didn’t permeate Glasnow’s attack has matured in the minors. Tim Williams noted in the changeup article that the reason they took the pitch away from his early on during his time in the organization was so that he could focus on commanding the four-seam fastball. Now, what has driven them into bringing the pitch back into the fold is that the changeup actually plays off of the sinker more than the four-seamer with the new tw0-seamer grip, and it adds another wrinkle to pitches with arm-side run.
Rather than rehash Tim’s article from this spring, I wanted to examine how he’s used it and how its fared this season.
To the first matter, take a look at his four-seam vs. two-seam usage this season:
Glasnow didn’t make the two-seamer a large part of the game early in the season as he barely tossed it at all in two of the games; however, it became used more frequently the 9th through the 12th starts.
Unfortunately, it wasn’t met with great success, as every one of his pitches saw an increase in hits and slugging percentage, even the devastating curveball. To make matters worse, the fastball whiff rate dropped to one percent regardless of which one was thrown.
He did walk fewer batters, but that was primarily the result of being more hittable, and when batters did make contact, the hard hit percent jumped from 25 percent to over 43 percent.
I checked the movement of the pitches to see if it had been slipping, but it continued to be a good distribution; although, in a piece by Alan Saunders from a few weeks ago, he pointed out that Glasnow was having some trouble with two-seamer running across the plate and maintaining movement the deeper he went into games.
Could pitch deception also be an issue?
With hitters all over Glasnow’s pitches, I thought perhaps he was having trouble with deception, so I looked into his pitch tunneling statistics. If you’re unfamiliar with them, it’s not a big deal; Baseball Prospectus just released them this year.
Before we dive into those statistics, I want to clarify one important item. These differential statistics that we will examine are the differentials between two consecutive pitches and not an average differential of all his pitches. Suppose Felipe Rivero faces one batter and requires four pitches (FF, FF, CH, FF) to retire him. The differential statistics will be measuring the variance between the first and second four-seamer or between the four-seamer and the subsequent changeup rather than taking all four and finding the average differential. This helps us distinguish if particular pitch sequences are successful or problematic.
Essentially, pitch tunneling refers to a pitcher’s ability to conceal what type of pitch he has thrown up until the point the batter has to decide whether to swing, This diagram from Baseball Prospectus is useful for dissecting that statement more:
We should be comfortable with the release point, which is used to determine release differential, a stat that measures how much variance in release point there is between consecutive pitches. For example, if a pitcher throws a fastball followed by a fastball, his release differential should be minimal regardless of deception abilities, but a strong deceiver will be able to minimize that differential even between different types of pitches.
When Glasnow throws the two-seamer, he’s been league average with the sinker/curveball combination but better than league average with everything else involving the sinker, so let us move on to the next tunneling statistic.
The second point is the tunnel point; this is the new term, which describes the location approximately 23.8′ from the plate where a batter must decide whether he will swing at a pitch. If from release until the tunnel point, a pair of pitches take very different paths, then the hitter might distinguish earlier what type or category a pitch might be.
League Average for this, tunnel differential, is .85, and Glasnow’s highest combination, four-seamer & sinker, comes in at .83 or better than league average. Almost every other pitch pair involving the sinker with the sinker is more than .1 away, which sounds minor but is quite a bit above average. What this means is that Glasnow excels at concealing the pitch up until the point a player has to swing.
Of course a pitcher can dominate without concealing if his stuff is truly untouchable.
A good reflection of that great stuff can be how much of a break differential exists between pitches of different types. Pitching is still vastly more complicated than that, but this can be one facet of determining that. Anyways, it is called post tunnel break, which is how much break happens once a pair of pitches goes from the tunnel point to the plate. You might think of it as how much “late break” occurs. League average for a pitch pair (regardless of frequency) was .25. Here are Glasnow’s pitch pairs:
I wouldn’t mean to suggest that a small break means a pitcher can’t or isn’t successful with a particular pairing, but it does on some level speak to a pitchers ability to miss bats. Glasnow not only flashes that ingredients of that capability, but he also conceals his pitches as well as the league’s better starters. Those top four combinations are among the top six percent of all pitching pairs, including those by relievers (for starters, he’s much much higher). Also, considering the curveball is his best pitch, it’s encouraging that is plays well off the sinker in terms of movement and deception, so it’s reasonable that Glasnow decided to tinker with throwing the two-seamer more
There’s no question that Glasnow’s performance was disappointing; however, I think the information above gives a lot of optimism for his as a starting pitcher in the future.
In the majors this season, Glasnow was determined to diversify his arsenal even if there were growing pains and it wasn’t ready for the majors. Now, he wasn’t sure which fastball to favor, struggled with location, and harnessing movement as the game progressed, but that can amount to the notion that he doesn’t have full command of his arsenal yet. And since one of those pitches is new and the other unused since high school, it shouldn’t have been expected to be otherwise.
I would fully expect that the more comfortable he grows with his newly diverse arsenal, the more he’ll be in a better place to succeed in the Pirates’ rotation.