A PITCHf/x scouting report on Zack Wheeler's first start


Super Tuesday last week has come and gone and of course the result has been a ton of superlatives about Zack Wheeler and his stuff. And clearly a large part of it is well deserved. However, there are a few misconceptions about Wheeler's repertoire that I'd like to clear up, and now that we have six innings of PITCHf/x data, I can do that.

For those who don't know about PITCHf/x, it's a system of cameras installed in every major league park in baseball since 2007-08. The cameras track every pitch thrown during each MLB game and record the location, movement, velocity, etc. of each. (PITCHf/x is also used to judge umpires, for whatever that's worth.) Just as importantly, the data is public, so anyone who wants to do so can take the data to look at a player's pitches for themselves. Alternatively, sites like Brooks Baseball are great resources for using the data to look at various pitchers at a whim and without the need to sift through mountains of data.

With Wheeler we only have one start to work with, so it's not worth going over the results of any of his pitches on Tuesday; after around five starts we'll have sufficient data to do that and see what's working and what isn't. Nevertheless, we certainly have enough data to look at the movement and velocity of the pitches and how those compare.

Wheelermvment_png_mediumFigure 1 and 2: Graph of the movement and Velocity of Wheeler's pitches.

To Read:

Vertical Break: the number of inches the ball drops/"rises" compared to how we would expect gravity to make a pitch drop. So a Fastball with Positive 10 Vertical Movement "*"rises" 10 inches more than it should if gravity was the only force acting on it; a curveball with -10 Vertical Movement drops 10 inches more than a pitch thrown that is just acted on by gravity.

Horizontal Break: The graph is from the view of a catcher or umpire behind home plate. So a pitch on the left side of the graph (and has "negative horizontal movement") moves in on righties and away from lefties. A pitch on the right side of the graph moves in on lefites and away from righties.

Legend for this Graph and All Subsequent Graphs:
Four-Seam Fastballs = Red Dots
Two-Seam Fastballs = Orange Dots
Change Ups = Dark Yellow Dots
Sliders = Blue Dots
Curveballs = Purple Dots

As you saw on Tuesday, Wheeler throws five pitches: a four-seam fastball, a two-seam fastball, a change-up, a slider, and a curveball. Let's go over each of these pitches in turn

The Four-Seam Fastball: Wheeler's primary pitch is a four-seam fastball which averaged around 95.8 MPH in his start on Tuesday. The pitch actually averaged a faster velocity earlier in the game, but Wheeler lost velocity in the last two innings, which is not uncommon for pitchers not named Justin Verlander. So, yeah, the velocity's pretty good.

The movement though? That's something we need to talk about. I've seen a lot of talk praising the movement on Wheeler's fastball, or describing the pitch as a "tailing" fastball. But the PITCHf/x data reveals that the pitch itself doesn't have a lot of movement for a fastball. In fact, the pitch's horizontal break - toward right-handed batters, as typical for a righty pitcher - isn't anything more than you'd see from an average four-seamer, and may actually be slightly less. In other words, it doesn't really have "tail." Similarly, unlike say Matt Harvey, Wheeler's fastballs don't really have that much "rise" as you see on some four-seamers. Harvey's fastballs have about an inch-and-a-half more "rise," which is part of what makes his upstairs four-seamers so deadly.

Now this is not to say there isn't anything notable about Wheeler's movement. For one, a few of his pitches actually showed a little bit of "cutting action," which is pretty impressive for a 96 MPH pitch (not a lot of "cut" but a little bit of what we would consider "cut"). That said, this doesn't appear to be deliberate - for example, the pitches we're talking about are the red fastballs on the right side of the fastball cluster, which were thrown to the opposing pitcher. If Wheeler could put on this cut deliberately, he might have an even deadlier weapon in addition to his normal four-seamer. But for now, it appears to just be something that'll occasionally happen with his grip and delivery.

None of this is to say that Wheeler's four-seamer is bad. Averaging near 96 MPH on a fastball is amazing and makes lesser movement look like a regular fastball with more movement. But it doesn't exactly have "tailing action." It really is a pitch that just blows by people via velocity and location.

The Two-Seam Fastball: By contrast, the two-seam fastball, of which Wheeler threw 16 on Tuesday, does have some "tailing action" - about 7.5 inches of tail in on right-handed batters compared to the 4.5 inches for the four-seamer. But, again, this isn't much compared to other pitchers' two-seamers. Similarly, the two-seamer has seven inches of "rise" (one less inch than the four-seamer) so it's not really much of a "sinker."

That said, again, this pitch has fantastic velocity: 94.6 MPH on average in that last start. And velocity is a strong factor in generating ground balls, so this pitch certainly can accomplish that when Wheeler needs it, though it's not likely to be a super ground ball pitch.

The Slider: The slider was Wheeler's primary off-speed pitch in his start on Tuesday; he threw 18 of them. It's very similar to Matt Havery's slider, averaging around 89 MPH but without much break (there's about two inches of break away from righties and four inches of "rise" on the pitch). Some clarification here: Many sliders have no "break" in any direction. What this means is that the pitch's horizontal movement is straight - it doesn't curve - and that the pitch's drop is basically what you'd expect from gravity (Wheeler's actually has less than you'd expect). But because a pitcher's release is from a point off-center, the end result of this is that the pitch hits the plate on an angle and thus still looks to a batter like it's breaking away from right-handed batters.

Again, like Harvey's slider, the velocity on this pitch is outstanding - basically 89 MPH. It's been said that this pitch was a late addition to Wheeler's arsenal, taught in the Mets' system, and Harvey has stated that his own high-velocity slider was suggested by Dan Warthen. I wonder if this is the case with Wheeler's slider as well, given the similarities.

Speaking of similarities to Harvey, Wheeler's slider seems to be a right-handed batter exclusive weapon (17 of his 18 sliders were to righties). This contrasts with his next pitch...

The Curveball. This is where Wheeler really diverges from Matt Harvey. Harvey's breaking ball is a 12-6 pitch without a ton of drop, though it has great velocity (averaging 84 MPH recently, which is incredible). Velocity is extremely underrated on breaking balls, as it increases the whiffs and ground balls (especially the latter) on the pitches, and Harvey uses his spectacularly.

Wheeler, on the other hand, uses a curveball averaging a little over 77 MPH - not a great speed - but with a large sweeping 11-5 action. He gets 5.7 inches of break away from righties (inside on lefties) on the pitch with 6.5 inches of vertical drop (+ gravity). Scouts reportedly considered Wheeler's curve his best breaking pitch up until recently, and it's easy to see why they'd love the movement. Still, with that velocity, I wonder if it'll truly be a great swing-and-miss pitch rather than simply a pitch that can freeze batters.

While this pitch was used against both types of batters, it was Wheeler's primary off-speed pitch - pretty much only off-speed pitch actually - against lefties in his last start. It'll be interesting to see if this continues.

The Change-up: Wheeler's final pitch is his change-up, which he threw twice in his last start. It's his other weapon against lefties, and has the same movement as his two-seamer but with a velocity around 86 MPH, making it a pretty typical two-seam fastball. We'll see if he throws it more as the season continues.


It's too early to tell which of these pitches is truly effective — and why — for Wheeler; we need a few more starts of data. Nevertheless, it's very interesting to note that three of Wheeler's main pitches function as they do because of his great velocity, and not because of great movement (the curveball is the opposite).

The next time someone raves about how much break there is on Wheeler's fastball or other pitches (besides the curve), give that person a slap. That's not how the Mets' star prospect rolls.

This FanPost was contributed by a member of the community and was not subject to any vetting or approval process.