Cristopher Sanchez is throwing harder. But how much is it helping?

Cristopher Sanchez has been one of baseball’s best stories, blossoming into a force for the National League-best Phillies. The 27-year-old left-hander, a reliever-turned-starter, has a 2.96 ERA through 18 starts, and earned a spot on the NL All-Star team as an injury replacement. 

Sanchez operates with a three-pitch mix, throwing a sinker, changeup, and slider. His changeup is the mix’s crown jewel, good for a 38.5 Whiff% and a .174 wOBA, steering both his elite ground ball rate (97th percentile) and chase percentage (98th percentile). 

And while we could spend all day lauding Sanchez’s changeup — arguably the best changeup in the game — it’s Sanchez’s sinker that captures our attention. 

Sanchez has seen a dramatic uptick in velocity this season. His sinker averages 94.4 mph, 2.3 mph faster than last season’s average. That’s the third-largest increase in fastball velocity among qualified pitchers, trailing only Colorado’s Kyle Freeland (+3.2) and the White Sox’s Michael Koepch (+2.6). 

This isn’t entirely novel, because Sanchez used to throw hard. After the 2019 season, MLB.com’s prospect rankings noted that Sanchez was “coming at hitters with a fastball up to 97-98 mph, consistently.” But control became an issue and, as The Athletic’s Matt Gelb reported, the Phillies tore Sanchez “down to studs,” opting to overhaul his mechanics and, at least in the interim, sacrifice velocity for control.  

It took a while, but the transformation worked. In 2023, Sanchez posted a BB% of 4.0, good for the 98th percentile. Meanwhile, the velocity of his sinker sank to its nadir, averaging just 92.1 mph. And while he threw his sinker a career-low 46.1% of the time, the pitch was mildly effective, posting a .362 wOBA but a Run Value of +7. 

But now, Sanchez is throwing harder than ever. And the faster the sinker, the more effective it becomes. 

SINKER	Pitch%	wOBA	Whiff%
>= 94 mph	30.8%	.346	12%
< 94 mph	5.7%	.425	7.5%

That’s a pretty marked difference, and it makes sense. For one, we’d expect a faster pitch to generate more swings-and-misses, and we’d also expect a pitch that generates more swings-and-misses to be more successful. Along those lines, if the pitch is more successful, we’d expect Sanchez to try and throw more of them — as he is doing, pretty clearly. 

And yet, despite all of this, Sanchez’s sinker still isn’t a very good pitch. Through the All-Star Break, it accounted for a -2 RV, the second-worst single-season pitch of his career. Hitters thrive off it, too: the sinker allows a .396 wOBA and a 47.2 Hard Hit %, plus a meager 10 Whiff%. While a sinker isn’t necessarily a swing-and-miss pitch, Sanchez still rates well below league average (13.8 Whiff%). Even with increased velocity, the faster sinkers merely account for a roughly league-average pitch.

So, Sanchez generates very little swing-and-miss off his sinker, while allowing consistent loud contact. That’s not a winning formula, especially when you consider that Sanchez throws the fifth-most sinkers in baseball. To take the next step — whether that be maintaining this level of success, or perhaps even getting better — Sanchez needs to adjust his sinker use. 

Let’s focus mostly on Sanchez’s attack plan against right-handed bats (RHB). An arms-and-limbs left-hander with a funky delivery, Sanchez stymies left-handed hitters. But he fares well against RHB, too (.645 OPS in 350 PA). Of qualified left-handed starting pitchers, Sanchez holds RHB to the ninth-lowest wOBA. There’s some pretty good company here. 

LH SP	wOBA vs. RHB
Max Fried	.238
Tarik Skubal	.247
Chris Sale	.257
Garrett Crochet	.259
Justin Steele	.261
Ranger Suarez	.264
Cole Ragans	.265
Sean Manaea	.275
CRISTOPHER SANCHEZ	.287

But as we dig deeper, we see that the sinker is a problem. Against Sanchez’s sinker, RHB have a .408 wOBA, and their xWOBA is actually 20 points higher. If we remove the fastball, here’s how Sanchez stacks up against his fellow LHP against RHB. 

LH SP	wOBA vs. RHB (NON-FASTBALLS)
Justin Steele	.162
Chris Sale	.198
CRISTOPHER SANCHEZ	.200
Max Fried	.203

So here’s what we have so far: Sanchez is throwing harder, and while velocity has helped, the opposition is still teeing off on his sinker. In particular, RHB — a subset of hitters that Sanchez dominates — are killing his sinker, which he throws 45.4% of the time. This isn’t a new problem: It’s the fourth consecutive season that RHB have a wOBA .389 or higher against Sanchez’s sinker. Those are elite levels. If Sanchez could figure out how to handle RHBs with his sinker, well, he would be nearly unhittable. You don’t have to squint to see it, either. 

How can he get there?

We know that Sanchez has already made a drastic change to his sinker this season, adding a near-unprecedented amount of velocity. Is it working? Against RHB, the answer is, well, sort of: 

RHB wOBA against Sanchez’s Sinker	2024	2021-23
>= 94 mph	.385 wOBA	n/a
< 94 mph	.440 wOBA	.397 wOBA

We see that Sanchez’s faster sinker is generating better results than his slower sinker, as we might expect. Yet the faster sinker is still being hit hard, and the slower sinker is being hit significantly harder than in year’s past. 

Let’s take a closer look at how Sanchez actually uses his sinker. As with any pitcher, Sanchez is vastly more successful when he gets ahead (.192 wOBA) than when he falls behind (.368 wOBA). That holds true for the sinker, too. Take a look at the pitch’s count-based split: 

Sanchez’s Sinker against RHB	Ahead in the Count	Behind in the Count
Avg. Pitch Velocity	95.3 mph	94 mph
wOBA	.356 wOBA	.404 wOBA
In-Zone Percentage	62%	61%

There’s a clear divide between when Sanchez is throwing harder, using his newfound velocity. When he’s behind in the count — when a pitcher needs his best stuff to get by — Sanchez’s velocity uptick vanishes.  

Linking this back to what we know about Sanchez’s history — his past reclamation to sacrifice velocity for control — we might expect that Sanchez throws slower with intent, in order to avoid a walk. His slowest sinkers, in this subset, are right over the middle, a good tell of a pitch that is grooved for a strike. But this actually isn’t necessary, since Sanchez’s in-zone percentage is more or less the same. 

The sinkers he throws when behind are confined to a specific location, on the outer-middle portion of the plate to RHB. It’s not a coincidence that this is where Sanchez’s sinker misses the most bats. When Sanchez is behind in the count, the hitter is likely to do the most damage, so Sanchez wants to maximize his swing-and-miss capabilities — while throwing a strike, so as to limit his walks. 

By contrast, when ahead, Sanchez dots his sinkers all over the place.

In other words, Sanchez seems to want his cake and to eat it, too. Maybe, then, Sanchez is sacrificing velocity to get to this specific spot, an idea that may be costing him.

As he moves through the rest of 2024 — and into a pennant race — Sanchez should alter how he deploys his faster and slower sinkers. Right now, when he’s behind in the count to RHB, Sanchez throws his sinker 69.3% of the time; the usage rate is actually fine, since he wants to stay away from his changeup in these counts, so as to not throw it in the zone. Clearly, these are the spots that Sanchez needs his sinker the most. So he wants his best sinker here, and his best sinker is the faster one. 

For all we know, this may just result in an incremental improvement. But for Sanchez — already so good, with two elite offspeed offerings — incremental could be enough to elevate him to yet another level. Take away a little damage off his sinker, and he becomes all the more tougher against RHB, continuing his ascent. This seems like a pretty good way to do it.