What Was Gavin Williams's Best Pitch During Rookie Season?

Spoiler, it was his curveball.

The Cleveland Guardians had three phenomenal rookie pitchers during the 2023 season who were all great in their own right. Gavin Williams was just one of those pitchers who will be in the rotation for years to come. 

Williams had a four-pitch mix that he used to keep opposing hitters on their toes. He threw a four-seam fastball, slider, curveball, and changeup. Each was effective in its own right, but one stood above the rest.

This go-to, punch-out pitch was easily Williams's curveball. Let's look at why. (All stats courtesy of Baseball Savant.)

Jul 26, 2023; Cleveland, Ohio, USA; Cleveland Guardians starting pitcher Gavin Williams (63) throws a pitch during the first inning against the Kansas City Royals at Progressive Field. Mandatory Credit: Ken Blaze-USA TODAY Sports / © Ken Blaze-USA TODAY Sports

Opposing hitters had trouble making contact off this offspeed pitch all season. Williams's curveball had a Whiff% of 35.2 and K% of 30.2. Each of these is the highest among his four pitches by a large margin.

His slider had a slightly higher PutAway% with a 22.8, but the curveball sat at a 17.8 percent put-out rate, which was the second-highest of his pitches and is still an elite rate.

As effective as this pitch was, Williams didn't throw his curveball the most. Only 235 of his 1,386 pitches (17 percent) were the curveballs. He threw his fastball and slider substantially more, but that doesn't mean they were better.

Not overusing the curveball arguably made it more dangerous since batters were always stuck guessing when Williams was going to utilize it. This off-speed pitch also wouldn't have been as great as it was without Williams's elite fastball which ranked in the 79th percentile in velocity.

Check out the overlay of the two pitchers provided by @PitchingNinja on X. The two pitches perfectly complement one another.

Gavin Williams, 96mph Fastball and 76mph Curveball, Individual Pitches + Overlay.

11th K pic.twitter.com/pmPNM8rFQr

— Rob Friedman (@PitchingNinja) August 8, 2023

There's so much to be excited about in terms of Williams's development and sophomore season. The curveball is proof that he's going to have an excellent pitch mix for years to come.