Describing the tools of pitching, through the stats and the eyes of scouts

Welcome to the second of our two-part series on how scouts and analysts evaluate the tools on a scouting report. This time, we turn our eyes to pitching. We’ll look at how each group grades out various pitch types, as well as the hoary tandem of command and control. New data sources have given us far more precise information on the physical movements of pitches, and also allow us to better track the locations of pitched balls as they cross the plate, which gives us new insights on the same categories scouts have used to grade pitchers for decades. You can see the first part of the series, which looked at the five position player tools, here.

Command/Control

Keith Law: Command and control are often mentioned together, like Bert and Ernie or chocolate and peanut butter, but they aren’t the same thing. Control is simpler to define and identify, while command is nebulous and evaluating it is more subjective. Control is the ability to throw strikes, period. It says nothing about good strikes, and has little to do with intent — it’s a pitcher’s skill at executing a binary variable, strike or not-strike, across all pitches.

Command is a bigger thing, harder to define and much harder to evaluate. Command is a matter of a pitcher throwing the ball where he wants to throw it and how he wants to throw it. It’s about hitting a spot versus hitting the zone. And it’s far more likely for a pitcher to have differing levels of command across his pitches than to have differing levels of control; many teams’ scouting reports separate fastball command from command of other pitches. I tie command to a pitcher’s ability to repeat his delivery, because that kind of repetition, especially when it comes to a release point, is a major input into whether the pitcher can put the ball where he wants it and make it move (or not move) as he desires.

I don’t think there are any current major-league pitchers with 80 or 20 control; the best control among MLB starters probably belongs to Shane Bieber or Zack Greinke, and I wouldn’t go above a 70 grade for either. Tanner Rainey has had the highest walk rate of the last two seasons for any pitcher with at least 20 innings, and he’s probably around 35 control, which is bad enough; you don’t actually want to see 20 control, not in person and certainly not if you’re a hitter.

Similarly, I wouldn’t give anyone in the majors 80 command right now — you can’t have a better command grade than a control grade, by the way, it’s an ontological impossibility — but Greinke and Max Scherzer jump out as guys who could at least have a case for 70 command. There are always a few 30-40 command guys on the tail ends of major-league rosters, but they seldom last long; Tayron Guerrero is one 30 command guy who spent most of 2019 in the majors, and, given his delivery, he’s probably never going to sniff average command. Elvis Luciano is another, as he was a Rule 5 pick from Low A and had command to match.

Eno Sarris: For the longest time, all we had for command and control, statistically, was a single number: walks. Walks per nine innings, walk percentage — the improvements were just much of the same, only chopped up better over time. Walk percentage is not terrible at showing us the pitchers that locate: Mike Leake, Hyun-Jin Ryu and Greinke sat at the top of the BB% leaderboard last year — but so did Scherzer, who seems to have better stuff than control, so the list doesn’t seem perfect.

Command and control are important to all manner of different facets of pitching, so they’ll show up a little in things like homer rate and ERA and the like. But in terms of really capturing the skills, we had very little for a long time.

PITCHf/x — Sportvision’s optical tracking innovation — came to baseball in 2006 and gave us a look at exactly where pitches crossed the plate. That allowed us to start talking about zone percentage, or how often a pitcher throws his pitches in the strike zone. Theoretically, that stat should capture control, since the definitions line up. But in practice? Lucas Giolito, Reynaldo Lopez and Zack Wheeler were in the top five last year by zone percentage. I wouldn’t call this an elite group of control artists.

Perhaps fastball zone percentage is a better metric since that pitch is often used to establish strikes. What do you think of the list?

Maybe. But Dallas Keuchel has the second-worst fastball zone percentage and he has pretty good control.

Let’s grade this one incomplete. (That bodes terribly for command, which is even harder to measure.) Baseball Prospectus took us a step forward when they developed their command stat, CMD. The top five pitchers when they last ran it publicly, in 2018 — CC Sabathia, Jake Odorizzi, Marco Gonzales, Kyle Hendricks and Corey Kluber — pass the smell test.

But this seems like a stat that measures elite control rather than command. Command is the skill of shaping a pitch the way you’d like to, and putting it where you want, which is not always a corner of the strike zone. So STATS Perform went to work on Command+, using scouting reports on the hitter and the pitcher, along with some use of the catcher’s target, and then a deciphering of the signs in order to judge where the pitcher intended to put the pitch and how far away from that point the pitch ended up.

Judging a pitcher’s intent is rife with noise but, in my opinion, it’s the only way to truly get at command. And the Command+ leaderboard from the end of last year is stacked with the best command artists in any rotation. It also passes the smell test and brings up many of the same names, but I believe the process better matches the tool we’re attempting to measure.

There’s still more work to be done. We’ve only had the capability to research this question well for a little more than a decade, so it’s not surprising, but it’s true. The scouts are probably ahead on control and command for now.

80 command: Kyle Hendricks
30 command: Sean Newcomb

Fastballs

Law: The simplest way to grade a fastball is with the radar gun, but that has gradually fallen out of fashion due to the greater awareness that major-league hitters can hit 100 mph if it’s straight or comes without deception. Faster is usually better, all else being equal, but if I see a pitcher blowing at 98 and hitters are turning him around — even if it’s just to make hard outs — I’m not calling that a 70 or 80 fastball; it plays down, or plays below its velocity. Hitters will often tell you if a pitch is any good, and if you see a guy throwing very hard and failing to miss bats with the fastball then the grade should reflect that. Gerrit Cole probably has the best overall fastball grade among current major-league starters, averaging 97.2 last year and missing bats with the pitch. Jordan Hicks throws harder but his fastball can be too true and he doesn’t have average command of it, so it might have been an 80 in an earlier era but now is a 70 or a 65. Aroldis Chapman was once easily the top of the scale and an obvious grade-80 pitch, but he doesn’t throw as hard as he once did and his fastball isn’t that exceptional in the upper 90s compared to when he would sit 101+. The low end of the scale is probably a 40; you really can’t pitch in the major leagues with less than that on a proper fastball.

Sarris: If you play with results, there are all sorts of ways to measure a fastball’s dominance. One such effort — based on using whiffs in the zone — identified Cole’s fastball as the most dominant, and that feels right. But if you’re scouting a tool, you can’t rely on these sorts of in-game results, and you want to know quickly if a pitch is good or not.

And, it turns out, the most important scouting tool when it comes to fastballs is still the same one it’s always been: the radar gun. Angels general manager Billy Eppler admitted something that everyone in the game knows when he said the single most important predictor of a pitcher’s future success is fastball velocity. Cole, Jacob deGrom, Wheeler, Walker Buehler — the list of the hardest-throwing starters is a good one.

But PITCHf/x provided some nuance once we were able to track the movement of each pitch. We discovered that “ride” — the lack of drop that helps a good four-seam fastball jump up on hitters — was good for whiffs and pop-ups. We found the data to be able to make movement heat maps like Dan Aucoin, of Driveline Baseball and now with the Phillies, put together for us here, which describes with colors (red is better) what good fastball movement looks like.

We're spending a lot of time upgrading our estimates of pitch quality (from 40ft). Here's our estimates of pitches at 95-98mph from medium/high slot dudes… Shows the importance of staying away from average + it's way easier to get into the next contour by adding carry vs. run pic.twitter.com/M6Bx1l885q

— Dan Aucoin (@dan_aucoin13) August 20, 2019

With the benefit of this sort of research, we can say that Aroldis Chapman’s fastball is the best in the business — which is probably driven mostly by his ridiculous velocity. But some more surprising names are in the top 20, like Nick Anderson, Tanner Rainey and Oliver Drake.

Of course, spin rate is a thing we started tracking with TrackMan’s entry in 2015, but that’s more of a “raw stuff” or building block metric — a pitcher with high spin can work on his spin efficiency to get more beneficial movement out his pitch, but the movement and velocity are still the key aspects. That’s why you’ll hear pitchers talking more often about improving their spin efficiency when they talk about spin. And oh, look at this: Cole, the starter with the best stuff number in Aucoin’s work, also has 99.5 percent spin efficiency on his four-seam fastball.

Well, I guess that was easy.

80 fastball: Gerrit Cole
30 fastball: Tommy Milone

Curveball

Law: Scouts have always been looking for curveballs with tight spin and sharp break; they can break downward (12/6) or have two-plane break (often 11/5), but the best ones have always seemed to have a lot of spin and thus appear to break very hard and late. The idea of low-spin curveballs being successful probably isn’t new, but I can say it’s not something I heard while I was first learning about how scouts evaluate pitches.

Charlie Morton’s curveball is the most effective in baseball right now, followed closely by the hammer that Stephen Strasburg throws; I wouldn’t object if you wanted to throw an 80 on either pitch, although I think if I were behind the plate for both guys and had no idea what the data said, I’d put an 80 on Strasburg’s and a 70 on Morton’s.

Sarris: The best curveballs combine sizzle and spin, it turns out. Velocity and drop move the needle the most, at least when it comes to whiffs and grounders. So, to find the best curveballs, you could do a simple search on FanGraphs — say, by asking, “what if you took the top 20 fastest curveballs in the league (min. 100 thrown) and sorted them by drop?”

That list checks out, though the starters should get a little bit more credit for being able to sustain that kind of velocity and movement over longer stretches.

Our understanding of what makes a good curveball is deepening as public research continues. We knew from the Astros that high-spin curveballs were good, though we don’t know if that’s just because they can be tweaked to be improved or if the spin itself is beneficial.

For example, Aaron Sauceda’s ACES score, which attempts to rank pitches by their innate characteristics of movement and velocity, includes spin — because it’s attempting to be predictive of future success, and spin rates improved that predictive ability. But what if that’s because a pitcher with a high spin rate can make mechanical tweaks in order to turn more of that spin into more beneficial movement on the pitches? Then ACES would have “predicted” the better outcome.

In terms of predicting if this one curveball will perform better than another one on spin alone, once you strip out the velocity and movement, I’m still skeptical. If you look through the top curveballs by spin, there are a bunch of good curves but also some (like those thrown by Chris Stratton and David McKay) that make you wonder if spin alone is a quality metric.

There is some evidence that pitchers benefit from being able to “mirror the spin” on their curveballs and fastballs — if the curve and fastball spin on the same axis, the hitter can’t tell them apart and both pitches perform better. That’s something that Rich Hill told me a while back but I was only recently able to show by using the numbers. Unsurprisingly, Hill’s fastball and curve spin axes mirror exactly, as they are 180 degrees apart … and so do Cole’s.

80 curveball: Gerrit Cole
30 curveball: Martín Pérez

Slider

Law: As with a curveball, a slider should have what appears to be sharp break and tight spin; both pitches are breaking balls and break away from hitters who hit from the same side — a breaking ball from a right-handed pitcher should break down and away from a right-handed batter. Sliders have to have “tilt” referring to the angle of their break; you may hear flatter sliders referred to as “sweepy” or even as “frisbees,” none of which is complimentary. Because they’re thrown differently from curveballs, with hand positions at release more similar to those of fastballs, sliders come in at higher velocities. There’s some sentiment that more is better, but it doesn’t always play out that way in practice — more break with less velocity can be more effective.

Clayton Kershaw’s was the gold standard for a while, and Chris Sale’s was pretty close, but both have slipped some the last few years as the pitchers lost some velocity and arm speed. Patrick Corbin’s slider is the best in the majors right now, probably a 65 or 70.

Sarris: As you can tell from Keith’s breakdown, sliders are tricky. There are many different ways to be successful with a slider — you can find success with the tight, sizzling power slider (deGrom and Justin Verlander), the power breaker with near-curve drop (Sonny Gray and Mike Soroka) or the slower hook (Kluber and Corbin).

As a result, it’s been hard to define a great slider using the numbers. Even my most recent attempt demonstrated there were more than a couple paths to a good breaking ball. And then when I looked into the relative importance of command and stuff, I ran into something I’d heard from a team analyst before: slider command might be more important than slider stuff in today’s game. With batters hunting fastballs more than ever, it seems like having a bendy pitch you can throw for a called strike is huge.

The bonus is, if you look at the top sliders by Command+, you get a list that features sliders that all vary in terms of velocity and movement — and a great list of sliders overall.

But that’s no definitive list of the best, I guess. We’re still figuring this one out in the public sector, and it’s possible that with so many different sliders out there, scouts are still better equipped to spot the best ones quickly.

80 slider: Jacob deGrom
30 slider: Kevin Gausman

Changeups

Law: Changeups can work in multiple ways. They can be effective pitches in their own right, thanks to their movement (called “action”) or they can be effective because of how they play off the pitcher’s fastball, thanks to similarities in his deliveries of the two or to overall deception. The first kind is easier to spot because you can see when it moves and how much; movement should be late enough to fool the hitter, and generally more is better unless it pulls the pitch too far out of the strike zone. The latter is a function of many different variables, including arm speed (which should be as close as possible to that of the fastball; if you slow your arm to throw a changeup, you might as well signal in semaphore that there’s a changeup coming), release point, and even your hand movement at release. If the hitter can see you turn over the changeup, he might be better able to recognize and adjust to the pitch.

Mike Minor’s changeup grades out the best among current major leaguers; he hides the ball extremely well, throws his changeup relatively hard and gets big, late-fading action on the pitch. Chris Paddack and Giolito both have plus changeups that I’d grade out at 70, but the results (such as the pitch values you’ll find on FanGraphs) show up more on their fastballs, which become more effective because hitters have such a hard time distinguishing the two pitches.

Sarris: It was during the study of changeups that we first were able to see in the numbers that there are different ways to be great with a single pitch type. As Keith pointed out, with changeups, it seems that two paths have emerged.

There’s the straight changeup, the changeup that moves more like a fastball but has a large velocity gap. You might recognize that description if you’ve watched Marco Estrada or John Means or Scott Kazmir. For whatever reason, though this pitch has proven efficacy, it’s not as popular as it used to be.

More popular now is the movement-centric changeup, the power change you see championed by Greinke and Félix Hernández, among others. More and more pitchers are choosing to throw a changeup that has a smaller velocity gap but a bigger movement profile, possibly because it doesn’t depend as much on the fastball.

Once you know there are largely two ways to succeed with a changeup, it’s not too hard to put them both on one leaderboard, as Sauceda did this year with ACES.

Uh, yeah, that’s right. Cole and deGrom have multiple 80 pitches. That’s how you ascend to the top of a sport. But let’s give another pitcher some love, especially since there’s no other starter that gets more whiffs per swing against the changeup than Luis Castillo (48 percent). Half the time a batter swings at the pitch, he misses — and 60 percent of the time he does make contact, it’s a groundball or a pop-up. Nasty.

80 changeup: Luis Castillo
30 changeup: Sonny Gray

(Photo of Cole: Mark Brown / Getty Images)