Curveball, I Love You, But You're Bringing Me Down

Braxton Garrett has been the Marlins' most consistent starter here in 2023, but there's an element of his deep pitch mix that continues to hinder his success.

In an era where more eyes are centered on the radar gun than ever before, Garrett's low-90s fastball velocity is an outlier. He ranks only in the eighth percentile among MLB pitchers in that category. However, he has demonstrated more than enough craft and guile to overcome his "lack of stuff" en route to accruing 3.9 Baseball-Reference WAR, improbably leading the Marlins rotation and ascending to sixth-best among all NL pitchers.

Garrett's ability to control the strike zone has been crucial. His 1.56 BB/9 is fourth-lowest in the majors (min. 150 IP). He's had 11 walk-less starts this season, which keeps him efficient and mitigates the damage wrought by hard-hit balls.

The variety of Garrett's pitch types makes him unpredictable for opponents. His sinker, slider and cutter have been worth 25 runs better than average collectively, per Baseball Savant.

If there is a crux to the former first-round pick's pitch arsenal, it's his curveball.

Scouts lauded it as Garrett matriculated through the Marlins farm system and it proved to be the most serviceable offering in his debut cameo in 2020. But it didn't contribute much to out-getting in the two seasons to follow:

• 2021: -3 RV, .444 BA, .722 SLG
• 2022: -1 RV, .381 BA, .619 SLG

The old saying "third time's the charm" didn't apply in this case, unfortunately. Hitters have torched Garrett's curveball this season to the tune of a .515 batting average, an absurdly high 1.091 SLG, and a minus-9 run value. Of the six pitches that he features, the curveball is also routinely hit the hardest, averaging 93.4 miles per hour off the bat, empowering his opposition to square it up with the regularity of Yandy Díaz or J.D. Martinez.

Here's where Garrett ranks in 2023 among the 171 pitchers to have at least 25 plate appearances conclude with a curveball.

• -9 run value: 168th
• -4.4 RV/100: 171st
• .515 BA: 171st
• 1.091 SLG: 171st
• 60% Hard Hit: 171st

While there is intangible value to having a "show pitch" that upsets hitters' timing, anything that generates outputs akin to a player whose attributes are turned up to 99 in MLB The Show is a net negative.

Hypothetically, what would happen to Garrett if he took the curveball out of the equation entirely?

Despite throwing the pitch only 8.5 percent of the time, it has yielded five of his 18 home runs. Stripping those from the record would drop his 2023 HR/9 rate from 1.04 to 0.75, a mark that would rank third among the 56 pitchers to throw at least 150 innings.

While there is no shame in allowing homers to Rafael Devers and Marcell Ozuna—as Garrett has with his curveball in 2023—it's not as easy to excuse against the likes of Jurickson Profar and...Carter Kieboom?

Garrett rides into the final week of the 2023 NL Wild Card race on a hot streak, having allowed only two earned runs in his last four starts. One of the keys to his success? Nobody has recorded a hit against his curveball during that span.

Replacing Garrett's curveballs with merely average pitches could conceivably elevate him from a rock-solid mid-3.00's ERA arm to an All-Star-caliber sub-3.00 ERA contract extension candidate.

In the meantime, Garrett has remained loyal to his curve by using it in all 30 of his appearances this season. That hasn't stopped the Marlins from going 21-9 (.700 W%) in those contests. It'll be fascinating to observe whether he continues to trust it with so much at stake for the Fish.

Photo by Jesus Sanchez/Fish On First