Aroldis Chapman: Predicting a Decline in Performance

Why this matters: Understanding these factors can help predict potential declines in performance for pitchers like Chapman, informing team strategy and player management.

Aroldis Chapman, currently a closer for the Boston Red Sox, has shown remarkable performance, but concerns arise as his fastball velocity decreases with age. Since entering the league in 2010, Chapman has been known for his blazing fastball. However, recent games show his fastball averaging around 90 mph, a significant drop from his peak. This raises the question: Is Chapman approaching a decline?

Chapman strategically adjusts his pitching effort. Data indicates he throws harder during two-strike counts and in one-run games, demonstrating his ability to elevate his performance when needed. Furthermore, his velocity tends to increase as he throws more pitches in an outing, suggesting a need to warm up.

However, control remains a critical factor. High walk rates correlate with poorer performance. In 2025, Chapman achieved a career-low walk rate, contributing to his success. Maintaining control will be vital for sustaining his effectiveness as his velocity declines. If his control diminishes, it could signal a more significant downturn in his performance. The Red Sox and fans should closely monitor Chapman's high-leverage, two-strike pitches; a velocity drop to 95 mph or lower in those situations could be cause for concern. Also, keep an eye on his control and zone percentage. A consistently high zone percentage is a good indicator that he will remain effective.

The most significant concern is the decline in his fastball velocity, which could impact his ability to overpower hitters.

Chapman adjusts his effort based on the game situation, throwing harder in critical counts and situations.

Control is crucial; a higher walk rate negatively affects his performance. Improved control in recent years has contributed to his success.

What do you think? Will Chapman's experience and control be enough to offset the velocity decline? Share this article with others who need to stay ahead of this trend!