It’s right there, in the definition of a changeup, on the league website. “The changeup is a common off-speed pitch, and almost every starting pitcher owns a changeup as part of his arsenal,” it says on MLB.com. The changeup — or at least a third pitch of some sort — is almost considered a fundamental requirement for starting.

And then there’s Spencer Strider, who broke the rookie strikeout rate record last year in 131.2 excellent innings, and did so without a changeup. Literally 95 percent of the time, he threw a fastball and slider, and only two starters threw 100+ innings and threw their primary two pitches more often. Headed into this season, the obvious question is if he can continue this dominance with two pitches.

“I don’t want to throw a pitch that doesn’t have the prospect of getting an out,” Strider told me late last year. “Worse pitches are contacted more, put into play more, you have worse command of them like I do with my changeup, and so you’re falling behind and relying on pitches that are going to be fouled off rather than swung-and-missed in a two-strike count. So what’s the point of it then?”

The numbers say throwing a third pitch even just 10 percent of the time softens a pitcher’s third-time-through-the-order penalty. In other words, players get more accustomed to the shapes and velocities a pitcher throws, and being able to mix it up means a starter can go deeper into the games. That makes sense in theory, but Strider himself still struck out 38 percent of the batters he saw in the fifth inning and later, and they only managed a .180/.251/.281 line against him, which doesn’t suggest they were seeing him any better.

Maybe that’s just one year of noise, but there is a sense that Strider’s two pitches were engineered to fit together.

“Our whole approach with pitching is to identify what you’re good at,” Strider pointed out. “For me it was the fastball. Low (Vertical Approach Angle), high vert, good velo, that’s going to be the centerpiece of the arsenal, everything is going to build off that.”

That fastball is indeed excellent, as it has a low VAA (-4.3 degrees, in the top 20 percent), a high vertical movement (17.6 Induced Vertical Break, also in the top 20 percent), and both of those things are augmented by his lower release point, which was also something he manufactured on purpose.

“When I rehabbed (Tommy John surgery) I figured out I was a vert guy, and I needed to be a four-seam guy, so I catered some of my mechanical things to increasing my extension and getting lower on release, and that’s made my fastball really good,” Strider said. “My initial mechanical queue was a forward drift where my hips would tilt up towards the plate, and so now I’m trying to keep my hips level, and that helps me get further down the mound.”

Only one starter, Ryan Pepiot of the Dodgers, threw from the same vertical release point and had more vertical movement. Strider’s is a top-five fastball in the league by Stuff+, which looks only at the physical characteristics of the pitch and sums up the influence of things like release point, movement, and velocity.

Once he had the fastball in hand, Strider and the Braves found the right slider to match that pitch. It had to be hard, and look like a fastball coming out of the hand.

“I had a curveball before, but I don’t supinate well, so I had to really hook it and try to get it over the top and roll out, so it didn’t have any velocity,” Strider said. “I was inducing a lot of movement but it wasn’t tunneling at that point. I need something hard with more vertical movement. Now I’m able to throw it hard, and the harder I throw it the more I can induce negative movement, so now I’m throwing it 86-88.”

Only three starting pitchers’ sliders resulted in lower production from hitters, so, yeah, Strider has two pitches, and they’re both insane. Haven’t we been told forever this doesn’t work?

Thanks to STATS Perform, we know there have been 193 pitcher seasons in which a starting pitcher put up more than 100 innings (prorated for 2020) and used only two pitches more than 90 percent of the time. Those starters had a 3.97 ERA and struck out 20 percent of the batters they faced. The league average starter over that time frame had a 4.24 ERA and struck out 19.8 percent of the batters they faced. So we actually see around 14 pitchers per season like Strider, and their average output is about the same as the average starting pitcher. Seems doable — except pitchers seem to be doing it less often every year.

Further delving into the data reveals a good portion of these players threw knuckleballs or changeups, so they don’t seem like great fits for this study. Strider threw a fastball and slider, and actually threw them 95 percent of the time. If we limit the pool in that way, we get 27 pitcher seasons since 2008, or about two in any given year. That cohort had a 3.98 ERA and struck out 19.6 percent of the batters they saw, so about the same as the larger sample. But if we focus on the few player seasons in which the player threw a slider and a fastball 95 percent of the time and also had an above-average strikeout rate, and an above-average ERA, we get his closest comps.

OK, these seem like his compatriots. Now we can see it’s not really that common to be this extreme — five in the last 14 seasons, so only one every three seasons — but a couple of these pitchers did manage some longevity and quality in the game with a slimmed-down approach. Justin Masterson in particular shows up on this list repeatedly. Brady Singer and Brad Keller attempted it in Kansas City most recently but fell off when we added results. Robbie Ray has benefitted from a small arsenal. It’s not impossible to do well like this, just not super likely.

Strider still doesn’t quite fit. You’ll notice a few of these other pitchers threw two different kinds of fastballs, which we combined for this study. Ray sort of famously added a sinker this year to help keep hitters off balance. And then there’s the quality of those fastballs. Strider averaged over 98 mph on his fastball last year. Dinelson Lamet’s was the only other fastball on here that averaged over 95.5, mph and he only did so for 69 innings in 2020. Safe to say Strider has the best fastball of the group.

“There are very few right-handed starters that average over 98 with a low VAA,” Strider affirmed. “It’s just hard to hit. The harder you throw, the less time they have to decide so it’s even harder to hit.”

He’s right. There are very few. Gerrit Cole (97.8 mph) and Dylan Cease (96.8 mph) are the only ones close at all.

“You can’t really build a better four-seam fastball than what he has as a starting pitcher,” said Chris Langin, director of pitching at Driveline Baseball. “(It’s) 99.5 mph, with impressive carry relative to his release height.”

The thing the other starters did have in common with Strider was slider velocity. All six of these pitchers, save Justin Masterson, threw their slider faster than league average. In fact, the group’s average (85.8 mph) is clear of the 85 mph benchmark that people use for slider quality — almost every slider over 85 mph is a quality one.

How important is breaking ball velocity?

Short answer: very

At 80 you have to have a very good profile in order to rate above ML average.

At 85? Almost anything plays.

Almost no way to throw a bad breaking ball harder than 85.

Charts Via @DrivelineBB Edge pic.twitter.com/mnLeECJq5F

— John Creel (@JohnEcreel) May 23, 2022

Why is a hard slider so important in these cases? Consider how a two-pitch pitcher has to work when a hitter is trying to “keyhole” them and is looking for one of the two pitches in a spot.

“You throw one fastball down, all of a sudden they have to think about that,” Strider said. “Even if they are sitting on the fastball up, still their brain cannot process 98 mph with 20 vertical inches of movement and still be on time every time and get the barrel to the ball, especially anyone that has a launch angle swing. I can tell what a hitter is trying to do, especially with a good catcher. When (Travis) d’Arnaud is catching, he knows what they are doing. As soon as a guy swings, he tells me what he’s trying to do. Once that happens, I have another pitch.”

Here’s the key:

“That’s why I have this slider, I built it so I could throw it, and it would look like a fastball,” Strider said. “Even if they noticed it, they couldn’t get under it and drive it. If the plan is to wait me out, I can throw fastballs, make them swing. If the plan is to jump me and be aggressive, I can throw sliders. You can’t cover all of it.”

So the track record says there have been some seasons like Strider’s, but it’s still rare and having a good fastball and a hard slider seems like the recipe for success. Strider has a hard slider and a really good fastball. Does the industry agree with him?

“We’re essentially stockbrokers,” Giants assistant pitching coach J.P. Martinez told me last year about Kevin Gausman, who primarily features a four-seam and splitter mix. “If you have five stocks and three are earning better than the other two, then let’s just pour the money into those three. In the past, in working with other teams and other pitching coaches, it’s been more about making the slider a feature pitch. The two main events for him are so high quality, we didn’t see the use in throwing the slider more often.”

In a related matter, Gausman threw the second-most sliders of his career the season after that piece was published. This is a thing that’s been debated forever, from scouts to coaches to analysts. It was an early debate among the founders of Baseball Prospectus — James Click, former Astros General Manager did not think you needed three pitches to start — and there remains no clear consensus to this day.

“Does it make sense to force usage on that third pitch just because that’s sorta the standard?” wondered Langin, of Driveline. “I’d say the concern is long-term contact quality maybe, as velo regression comes.”

“There are definitely examples of pitchers dominating with two pitches. Robbie Ray won the Cy Young Award with two dominant pitches less than a handful of years ago,” said one executive in player development who works with pitchers. “I think there is value in practicing other pitches and other variations of pitches to improve awareness of adjustment and feel for the ball but using those pitches in-game would just have to depend on those pitches’ quality.”

So the industry seems OK with it, provided it works, and yet there are fewer pitchers doing it every year, and Strider’s dominance with two pitches has been rarely matched. Can it work for the Braves pitcher, with his two dominant offerings? We’ll see. The pitcher himself is definitely still working on some wrinkles.

“I throw (the changeup) so infrequently, so when it’s good I sort of forget about it and when it’s bad I remember it,” Strider joked. “I don’t find it as fast. I’m tinkering with it more often. The slider, it’s there, I pick it up and I can throw it. It’s a power change because I throw hard, but I want it to be slow. I want it to be slow and more horizontal movement, I’m looking for something to move to my arm side.

“It’s more like a frustration than anything.”

He’s working on a curveball, too, and a cutter is a possibility. Those pitches could become more important as he ages, as pitchers lose velocity as they age. But it’s still all about what he expects from a pitch.

“When I throw my fastball and slider, I expect a miss. That’s what I want, that’s my goal, that’s what the pitches are supposed to do,” he said.

When he says it that way, it really seems like a solid approach. It’ll still be fascinating to see how this extreme two-pitch experiment works, since there really isn’t much of a precedent at his level of dominance.

(Top photo: Kevin C. Cox / Getty Images)