Are the Cubs at the forefront of a sinker revolution?

Chicago Cubs pitchers are pioneering a completely new type of sinker.

Over the past decade, sinker usage has declined across Major League Baseball. Pitchers have instead opted for high-velocity four-seam fastballs with carry atop the zone. Their reasoning is simple: they want to combat a hitter’s launch angle and generate whiffs.

No wonder the sinker — the easiest pitch to hit — is unpopular.

Cubs pitchers, however, have embraced the sinker in career-altering fashion. Among the adopters include veteran World Series champion Kyle Hendricks, former independent league pitcher Tommy Nance and up-and-coming arms Adbert Alzolay and Justin Steele.

These Cubs pitchers aren’t throwing sinkers for grounders, but rather they are throwing elevated sinkers towards batters’ wrists for whiffs. Hendricks was the first Cub to implement high sinkers, which happened a couple of years ago. Soon thereafter, Alzolay, who didn’t even have a sinker prior to 2020, developed a mid-90s sinker with which he hammers the top zone. And now Steele is the latest Cub to embrace the elevated pitch.

In the figure below, you will see the Cubs’ emphasis on elevated sinkers. This figure represents vertical sinker location (i.e., the height at which sinkers are thrown off the ground). The gray dots represent a pitcher’s average sinker vertical location (i.e., height off the ground), whereas the red dots specifically represent Cubs pitchers.

Not only are Nance, Hendricks and Steele elevating their sinkers, but they are doing so in the top percentile. Closely behind them are Adrian Sampson and Alzolay. And just above league average is Manny Rodríguez, the Cubs’ young potential late-inning reliever who throws triple-digit fastballs.

Why are the Cubs throwing high sinkers? Pitching coach Tommy Hottovy hasn’t been asked this question yet, but he has discussed a relevant concept called “Seam Shift Wake.”

“What makes a pitch effective is the perceived movement that the hitter thinks is going to happen,” Hottovy told The Athletic’s Sahadev Sharma. “A hitter has seen so many pitches move a certain way with a certain spin. When they see that same spin and they go to react and it’s moving differently than normal, those are the types of pitches you’re trying to create. That’s why it’s so unique and difficult to do. When they do it, that’s when you have those outliers, the pitches that look like they should be going one way and go another or move further than they should.”

According to research led by Driveline, sinkers are most malleable to Seam Shift Wake. They even noted Hendricks was among the league leaders in Seam Shift Wake. In essence, a sinker with heavy Seam Shift Wake thrown high in the zone might act as a change-up. Think about it for a second. You’re up to bat, facing Hendricks, and see an 85-88 mph pitch thrown towards your wrists. Not only are you expecting minimal movement because it’s an elevated fastball, but you might not even be expecting the sinker to move that much. This is a recipe for whiffs, and it’s perhaps why Hendricks’ sinker whiff rate was nearly 100 percent greater than league average in 2020.

Ironically, though, Hendricks’ elevated sinkers might’ve contributed to his 2021 struggles. Throughout 2021, some hinted that Hendricks might be tipping his pitches. Whether that was indeed the case hasn’t been reconciled, but clearly Hendricks’ horizontal release point was a significant contributor to elevated sinkers. Statistical analysis suggests the chance that Hendricks’ vertical release point randomly led to elevated sinkers is 0.000000000000000005%.

Maybe, then, this is an intervention target for Hottovy and Hendricks.

Altogether, Hottovy’s vision for elevated sinkers deserves attention. While there are inherent risks, the concept is innovative and has already led to dramatic results.

For now, Cubs pitchers might be changing the purpose of a sinker in Major League Baseball.