MLB Best Curveballs: The Best Curveballs of 2018

HOUSTON, TX - SEPTEMBER 18: Houston Astros starting pitcher Charlie Morton (50) relaxes in the dugout during the baseball game between the Seattle Mariners and Houston Astros on September 18, 2018 at Minute Maid Park in Houston, Texas. (Photo by Leslie Plaza Johnson/Icon Sportswire via Getty Images) /

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ST. LOUIS, MO – SEPTEMBER 14: Jack Flaherty #32 of the St. Louis Cardinals pitches against the Los Angeles Dodgers in the first inning at Busch Stadium on September 14, 2018 in St. Louis, Missouri. (Photo by Dilip Vishwanat/Getty Images) /

Jack Flaherty

Cardinals rookie Jack Flaherty ranks number five in this assessment. Flaherty had a coming out party in 2018 as he posted a 3.34 ERA, 3.86 FIP and a 2.3 fWAR in 151 major league innings, while striking out nearly 30% of the batters he faced. He even finished fifth in the National League Rookie of the Year Award race in a historically stacked field.

He had success this year relying mostly on his fastball but also with a good mix of sinkers, sliders and his curveball that worked as his out pitch.

His curve has above average horizontal and vertical movement, but it has below average spin. However, he did an exceptional job locating the pitch low and outside of the zone. This helped him produce an extraordinary 49% whiff rate on the pitch. The incredible lack of contact also led to his impressive .178 xwOBA on his curveball.

Flaherty only throws his curveball around 11% of the time but he gets such a high amount of swings and misses on the pitch that it is truly one of the most elite pitches in baseball. There has been a trend in baseball over the past few years of pitchers throwing more curveballs and perhaps this is a strategy that Flaherty could employ moving forward. This isn’t totally necessary as his other pitches are also really good, but it will be something to watch in the future.

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