MLB best breaking ball for 2023 belongs to “uncle charlie”.
The fifth-best pitch in MLB, based on run value, was Charlie Morton's breaking ball.
Earlier in the offseason, there was speculation about whether the Atlanta Braves would exercise the 2024 club option for starting pitcher Charlie Morton, who had recently turned 40, or if he would opt for retirement in Florida.
Ultimately, Morton chose to return, expressing confidence in his curveball. According to MLB Statcast, Morton’s curveball stood out as the most effective breaking pitch in the 2023 season, boasting a +25 Run Value. (A brief explanation of “Run Value”: It measures the effectiveness of a pitch in preventing runs in specific scenarios, considering base runners, ball-strike count, etc. A higher positive number indicates better run prevention compared to other pitches in the same scenario.)
Among the top five pitches on the leaderboard, three were fastballs, with Gerrit Cole’s four-seamer (+29) leading the pack, followed by Logan Webb’s changeup (+28), Zac Gallen’s four-seamer (+27), and Chris Bassitt’s sinker (+27). Morton’s curveball allowed only a .177 batting average and .258 slugging, making it a dominant force. It was thrown 43.2% of the time, resulting in a 42.0% swing-and-miss rate and contributing to 37.1% of his strikeouts.
In contrast, Morton faced challenges with the effectiveness of his fastball, ranking as the least effective pitch among all Braves pitchers who faced at least ten batters in 2023, with a -12 run value. The fastball, averaging 94.8 mph, allowed a .297 batting average and .487 slugging.
Throughout the season, Morton seemed to recognize the issue with his fastball, gradually reducing its usage from an initial 35% to just 29.4% by September. As Morton enters his age 40 season, there’s a discussion about potential adjustments to balance his pitching arsenal. While he occasionally threw a sinker and cutter in 2023, the sinker performed worse than the four-seam on a rate basis. However, the cutter was generally neutral. Enhancing the horizontal movement of the cutter, which currently averages 0.5 inches of break (130% below the MLB average for cutters), could provide a valuable alternative to the standard fastball moving forward.
