Hunter Greene’s New Go-To

Hunter Greene started the 2022 season off with a bang. An audible one, if you were sitting near home plate: Greene topped out at 102.6 mph in his second start of the year, averaged nearly 101 mph on his fastball, and generally looked like an entirely new type of pitcher, a starter with closer velocity.

A funny thing has happened since, though. That fastball didn’t play out quite how you’d expect. After those initial two starts, Greene lost a bit of zip on the pitch, and hitters stopped missing it. He drew 21 swings and misses in his first two major league outings; it took him another six starts to match that total. After walking just two hitters in those first two starts, he walked eight in his next two. It was time for an adjustment.

Consider that adjustment made. In his last seven starts, Greene looks like a top-flight major league starter again. He’s striking out a third of the batters he faces, walking less than 10%, and pitching to a 3.20 ERA (and 3.47 FIP) beginning with his May 10 start against Milwaukee. He’s going deeper into starts. And after the Brewers tormented him for five home runs on May 5, he’s allowed only five in these last seven starts over nearly 40 innings of work. How has the starter with the fastest fastball in the game done it? Exactly how you’d expect – by de-emphasizing his fastball and leaning on his best pitch, an upper-80s slider.

It sounds strange that a guy with a truly outlier pitch – and such a measurably excellent one at that – would pitch off of his breaking ball. But sliders benefit from extra velocity, too, and Greene’s combines speed with sharp movement on its way to home plate. Not only that, but he manipulates the pitch extremely well, flipping it in for strikes or as a wipeout at-bat ender with equal aplomb.

In his start on Saturday, he started 12 of the 20 Cardinals he faced with a slider, netting eight strikes, three balls, and a fly out for his troubles. When you go up there looking for 100 mph up in the zone, what are you supposed to do with this?

That’s a tough way to start an at-bat, but it’s nothing compared to what happens if Greene gets you in the hole. Here, let Tyler O’Neill demonstrate:

That’s the same pitch, and yet it behaves completely differently. When Greene releases it on that lower plane, the bottom drops out. But even in the zone, hitters haven’t fared well against Greene’s slider. They’ve come up empty on 25% of their swings against it, meaningfully higher than league average for all sliders, and when they do put it in play, it’s all soft contact and pop ups; Greene has allowed a .274 wOBA (.260 xwOBA) when he throws a slider in the zone and opponents put it in play. That compares to a .362 wOBA (.394 xwOBA) for the league as a whole. In other words, even if he throws it where batters can hit it, they struggle to square it up.

It sounds strange for a starter to throw his breaking pitch half the time. Greene stands at 49.6% in this seven-start stretch I’ve been extolling as his breakout. He gets away with it by having the pitch serve multiple roles: it’s both a setup and putaway pitch thanks to his ability to manipulate the location and break.

Early in the count – with zero or one strike – he throws it around the zone quite frequently, about half the time. Take the pitch to Tommy Edman from up above, or this 1-0 pitch to Paul Goldschmidt. Here, Greene started him with a slider he overcooked and bounced, then came back to even the count:

After evening up the count, Greene came back with another slider in the strike zone that Goldschmidt fouled off. From here, Greene switches to hunting for a strikeout, throwing his slider for a strike only 33% of the time. Mostly, he’s looking for a chase:

That’s a whiff-or-take pitch; if Goldschmidt swings there, he’s probably not making contact. It’s a useful pitch to have in your bag for when you’re up in the count; in fact, Greene threw essentially the same slider on the next pitch of the at-bat. But what really makes the slider most effective? It’s when you can complement it with this:

That’s almost unfair. Greene’s slider drops about 20 inches more than his fastball on its flight home. Thus, as Goldschmidt clocked the initial trajectory of the pitch, he had to swing at it. If it were a slider, it could easily clip the bottom of the zone. And he almost certainly thought it was a slider; Greene had thrown him five straight sliders to open the at-bat. And if you’re looking down and slow, high and fast is going to result in a lot of weak fly balls.

This argument – hey, fastballs and sliders move differently – isn’t an obvious reason to use a slider as a primary pitch. You could imagine an at-bat with five straight fastballs to Goldschmidt, followed by a slider he flailed over for strike three. But using your fastball first is dangerous, even if you can touch triple digits. Greene’s fastball doesn’t boast standout movement; it’s more two-plane than pure backspin, and his release point is fairly standard, which means hitters have seen a lot of similar-looking, albeit slower, fastballs in their lives.

In fact, if you look only at the results, Greene is still throwing his fastball far too much. When batters make contact with the pitch in the strike zone, they’re absolutely tattooing it, to the tune of a .471 batting average, .926 slugging percentage, and .598 wOBA. This isn’t a case of some fluky groundball doubles, either; opponents are barreling up 15% of the fastballs they put in play, and hitting 40% of them 100 mph or harder. Sure, it generates whiffs – when Greene throws his fastball in the strike zone, batters come up empty on 25% of their swings, six percentage points higher than league average – but the loud contact more than makes up for those extra whiffs.

You think Greene doesn’t know that? He’s essentially mothballed his fastball early in counts. In 0-0, 1-0, 0-1, and 1-1 counts – where a strikeout isn’t on the line but hitting the zone isn’t a necessity – Greene is throwing his fastball only a quarter of the time since that arbitrary May 10 endpoint I set earlier in the article. On Saturday, that number dipped to 18%, his lowest mark of the year. If you want to sit on Greene’s fastball early in the count, you’re going to either be taking sliders for strikes or putting awkward swings on them.

With two strikes, the best quality of Greene’s fastball – more swings and misses thanks to more velocity – makes it a useful offering again. In this Saturday’s start, his fastball usage was actually higher with two strikes than it was early in the count. You could call that pitching backwards, but given how Greene’s pitches perform, it’s more like pitching forwards. His slider is the one he can spot for strikes, his fastball is at its best when he can elevate it above the zone and a whiff ends the at-bat, and working “conventionally” wasn’t working for him.

Will Greene’s inverted form keep paying dividends? It’s certainly too soon to tell. Hitters have looked foolish against his slider so far, and it’s an excellent pitch even if the hitter knows it’s coming, but when the only choice is slider or fastball, it’s far easier to make an adjustment at the plate. Sequences like the one against Goldschmidt – five sliders followed by a putaway fastball – won’t work so well if batters are sitting on sliders in the zone early in the count, and I think they increasingly will given Greene’s recent pitch usage.

A third pitch would help keep batters honest, whether that’s increased usage of his changeup or a new pitch, perhaps a cutter to sit between the fastball and slider in terms of velocity and movement. And Greene will likely continue to vary his usage; a few early-count fastballs go a long way when you can get them over 100 mph. It’s too soon to tell whether Greene will be able to keep up his recent string of success as hitters develop a book on him. But for now, he’s fulfilling the promise he showed as a prospect – and he’s doing it by ignoring his high-velocity fastball and doubling down on his slider, a microcosm of the last five years of major league pitching.