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Five Under-The-Radar Prospects With Great Curveballs

R.J. Dabovich (Brian Westerholt Four Seam Images)
R.J. Dabovich (Brian Westerholt/Four Seam Images)

The bender, the hook, the hammer, the downer—the curveball goes by many names. It’s the first non-fastball pitch many baseball fans can identify in the early stages of their fandom. There’s maybe no single shot, throw or trick in any sport as aesthetically pleasing as a well-executed curveball. While sliders, cutters and hybrid slurves have become the most common breaking balls in professional baseball, there are still plenty of plus curveballs floating around the major and minor leagues.

Today we examine five under-the-radar pitchers with plus benders who are worth keeping an eye on. The analysis is broken down by discussing what type of curveball each pitcher throws, how the pitch moves and what makes it special in each of these hurlers’ arsenals. 

R.J. Dabovich, RHP, Giants

One of the most notable relief-only prospects in the minor leagues, Dabovich pairs one of the best four-seam fastballs in the minors with one of the best curveballs, both from a movement and results perspective. While Dabovich sits mid 90s with his four-seam, generating an elite level of ride, his curveball is among the hardest on this list. The pitch sits 84-86 mph on average and has been clocked as high as 89 mph. While it lacks the depth of a traditional curveball, its combination of velocity and late vertical drop as it approaches the plate makes it incredibly difficult for batters to hit cleanly. The results back this as well, as batters have whiffed on the pitch on more than 50% of swings against it, and over 40% of those swings were classified as chases out of the zone. Dabovich has shown the ability to consistently fool hitters with his curveball, getting a high rate of swings and subsequently whiffs and chases on those swings. Dabovich is a potential late-inning threat in the coming years for the Giants thanks to the combination of his powerful four-seamer and elite breaking ball.

Ben Casparius, RHP, Dodgers

Casparius, a UConn product, was a fifth-round selection by the Dodgers in the 2021 draft. He made his full-season debut late during the 2021 season with Low-A Rancho Cucamonga and returned there to begin his 2022 campaign. The 6-foot righthander made 27 appearances this season between Rancho Cucamonga and High-A Great Lakes. He struggled with command and keeping the ball in the ballpark throughout the summer with the Loons, leading to an inflated ERA. While his fastball was hit hard, Casparius’ trio of secondaries showed promise—a high-80s cutter-like slider, a mid-80s changeup that generates whiffs and a bender curveball with high spin rates that generates excellent results. Casparius’ curveball is for all intents and purposes a sweeper (depending on the pitcher these can be classified as a slider or a curveball). He sits 80-82 mph on the pitch with over a foot of horizontal break on average. Hitters rarely saw the pitch well this season, whiffing on over 40% of swings and chasing out of the zone on over 30% of swings against the pitch. Casparius’ ability to spin the ball is evident in his standout spin rates, as he generates on average between 2,800-2,900 rpm of raw spin on his breaking ball. Casparius, who's spent time working as a starter and reliever, could be an interesting name to follow as he learns to leverage his strong array of secondary pitches.

Andrew Baker, RHP, Phillies 

A 2021 11th-round pick by the Phillies out of powerhouse Chipola (Fla.) JC, Baker is a power reliever in the purest form. Across 46 appearances, split between two levels, Baker struck out 72 batters over 54.1 innings in 2022. He seemed to get stronger as the season went along, as Baker allowed just one earned run across 10.1 innings of work following a late-season promotion to Double-A Reading. The righthander has eye-popping velocity. He can ramp his fastball up to 101 mph, and he sat 98-99 mph on average this season. While his fastball may light up the radar gun, his curveball is easily his best pitch—a mid-80s breaking ball with slurvy two-plane break. Baker's curveball generated the highest rate of whiffs against it of any pitcher on this list at over 60%. Beyond generating a high rate of whiffs, Baker has shown the ability to command the pitch to high-performing areas in and out of the zone. On an accelerated path to the major leagues, Baker, while less heralded than other arms in the Phillies system, is part of the organization’s next wave of premium pitching talent. The two-pitch power reliever could factor into the Phillies bullpen as early as next spring.

Landen Roupp, RHP, Giants 

Drafted by the Giants in the 12th round of the 2021 draft out of UNC Wilmington, Roupp has had a breakout 2022 campaign. The righthander climbed three levels of the minors, producing a 2.60 ERA and 152 strikeouts to 37 walks over 107.1 innings. Roupp features a four-pitch arsenal composed of a low-to-mid-90s sinker, a slider, a changeup and a curveball. The mid-70s bender with heavy two-plane break accounted for nearly 50% of Roupp’s pitch usage in 2022. The pitch isn’t split-dependent either, seeing primary usage against both righthanded and lefthanded batters. The pitch has tremendous depth, getting both heavy horizontal break and vertical drop with an elite level of raw spin, averaging 2,900-3,000 rpm. Despite heavy usage the pitch still generates whiffs at an elite rate, as Roupp generated misses on over 40% of swings against his curveball this season. His ability to generate whiffs out of the zone was particularly notable as opposing batters chased the pitch on over 40% of swings. HItters did very little damage overall against Roupp’s curveball, and he used it consistently to drive swinging strikes and weak groundball contact. Roupp’s long-term role may be out of the bullpen, where his sinker and curveball combination would play well. His deep arsenal of pitches and success as a starter late in the 2022 season gives him a shot to develop as a starter for now.

Riley Martin, LHP, Cubs 

The lone lefthander on this list, Martin also throws the most traditional downer style curveball, getting more than a foot of vertical drop on the pitch. Drafted in the sixth round of the 2021 draft out of Division II Quincy (Ill.), Martin was a starter for parts of five seasons for the Hawks, but has worked almost exclusively as a multi-inning reliever as a professional. After making his pro debut with Low-A Myrtle Beach following the 2021 draft, Martin returned to the level to begin 2022. He dominated across four appearances with the Pelicans, striking out 27 batters across 13.1 innings of work. He saw a promotion to High-A South Bend at the beginning of May and made 27 appearances for the Cubs, striking out 93 batters across 69.1 innings of work. Martin works primarily off of a low-to-mid-90s four-seam fastball, mixing in a trio of secondaries in a mid-80s slider, a mid-to-high-80s changeup and a low-80s curveball. Martin sits 80-83 mph on the pitch, generating over a foot of vertical drop with average spin rates in the 2,600-2,700 rpm range. Batters struggled against the pitch this season, hitting just .120 against it with a whiff rate above 40% and a groundball rate north of 50%. An older small school college arm with a unique lefthanded pitch mix and an innate feel for spin, Martin could carve out a role as a matchup-driven lefthanded reliever capable of getting six outs each outing.

Colby White (Brian Westerholt Four Seam Images)

The Best Fastballs Outside The Top 100 Prospects

Prospect writer Geoff Pontes shines a light on some of the top fastballs in the minor leagues.

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