Digging into the new slider that Daniel Norris is throwing

Years ago, Daniel Norris was among the league’s most promising prospects due to an extraordinary changeup. Indeed, Norris’ spin axis, velocity, and vertical breaking action was and is unlike any other in MLB.

Nonetheless, Norris struggled to prevent runs due reasons that the Cubs hope to reveal.

Recently, the Cubs pitching infrastructure targeted Norris’ slider. Craig Breslow’s pitching group of Tommy Hottovy and Daniel Moskos believe Norris has potential to prevent runs by throwing a “sweeping slider.” In fact, Moskos was particularly successful implementing a sweeping slider with the New York Yankees’ young pitchers.

Moskos immediately started working with Norris to develop this fascinating sweeping slider in spring training, as The Athletic’s Sahadev Sharma pointed out in this article.

“The process of learning it, when I hear sweepy, you think side spin,” Norris said. “But Daniel (Moskos) has been really good, he said think of throwing a curveball and the grip will take care of the movement.”

In Norris’ first outing as a Cub, he threw several sweeping sliders, and the differences compared to his 2021 slider are striking.

The most striking differences are horizontal break and velocity. His new pitch sweeps nearly three times more than last year’s slider and is thrown almost 8 mph slower, as illustrated in the figure below.

In addition, Norris’ new slider might have greater vertical break, but it’s too early to tell. Three of his Opening Day sliders showed more dropping action than any of his sliders from last season, but there was big variation in vertical break among all Opening Day sliders.

One reason Norris’ slider is moving with more sweeping action is new spin axis (i.e., the degree at which the pitch rotates). Last year’s slider was thrown around 275 degrees, whereas this year’s slider is thrown closer to 300 degrees and higher. The change in spin axis actually resembles a curveball, which is how Norris described his grip on the slider.

Enough of these figures. What does the actual slider look like on video? Here’s an example from Opening Day. This slider was sweeping across the zone and was thrown 75 mph. Willson Contreras actually stood up in his stance anticipating the pitch would finish higher in the zone.

In comparison, here is a slider thrown by Norris as a Brewer. Notice how it’s thrown 84 mph and the breaking action isn’t quite as sharp.

Although it’s exciting to see Norris throw a new pitch that has clearly more movement, it might not be THE answer. We know he has also struggled with command over the years and will likely need to sharpen his control.

But the reason I’m highlighting Norris’ new slider is to emphasize the significance of the Cubs’ pitching infrastructure. Over the last couple years, they’ve successfully helped Ryan Tepera, Rowan Wick, Jeremy Jeffress, Kyle Ryan, Adbert Alzolay, Justin Steele, and so many others.

Words here fail to express my excitement and intrigue about what’s next for not only Norris but the rest of the bullpen and young Cubs pitchers.

The Cubs are clearly trending towards the forefront of pitching science, and Norris might end up being yet another success story.