Over the past four seasons, new Cubs pitcher Sean Newcomb has only thrown 118 innings. Ultimately, his limited role and inability to prevent runs (2021: 4.70 ERA, 4.40 xERA) forced a designation for assignment by the Braves.

Yet despite these red flags, the Cubs still acquired Newcomb for veteran reliever Jesse Chavez this week. Why?

Newcomb, a former 15th overall draft pick, has a cartoonesque curve ball. In fact, Newcomb’s spin rate ranks among the best in MLB. Only 5 percent of curves thrown have more spin than Newcomb’s curve, which is illustrated by the figure below.

Newcomb is able to translate hyper-spin to actual vertical break. Essentially no other pitcher in MLB throws a curve with Newcomb’s max vertical break. That is, his curve is perhaps the nastiest pitch if you solely consider vertical break.

Let’s take a look at this sharp-breaking curve. Here’s a clip from late 2021 in which he induced a sword from Brendan Rodgers.

Knowing Newcomb’s curve rates among the best in MLB, I’m asking why he didn’t succeed with the Braves? The answer is multi-faceted and not obvious. For instance, the tall lefty’s walk rate was nearly five batters per nine innings. He also generated league average whiffs. Most notably, he didn’t throw his curve in high leverage situations, instead opting for his 4-seamer and cutter.

Indeed, Newcomb only threw a curve in 15 percent of his total pitches during the 2021 season. Maybe the reason for such limited usage is due to confidence or likelihood to fall behind the count? I don’t know.

Regardless, it’s known that Newcomb’s curve is among the best in baseball. Now it’s up to Tommy Hottovy and Daniel Moskos to optimize that curve in the form of sequencing, frequency shifting, and/or improving other pitch types.