The Impact of Pitch Counts and Days of Rest on
Performance among Major-Leauge Baseball Pitchers.

Bradbury JC and
Forman SL. J Strength Cond Res. 2012; [Eup Ahead of Print].

A current strategy to
reduce injuries among pitchers is to limit the number of pitches a pitcher is
allowed to throw. Although this is increasingly seen in baseball, little
research has evaluated pitch limits and their effectiveness in maintaining
pitching performance among adult pitchers. Therefore, Bradbury and Forman
examined the impact of pitches thrown as well as days of rest on the
performances of major-league baseball pitchers between 1988 and 2009 who started
games after less than 15 days of rest. A cut off of 15 days was used to
eliminate data from pitchers coming off the disabled list and to account for a
normal starting pitching rotation. Data on 1,058 pitchers, over 22 seasons,
were evaluated via the open-access website (partnered
with the National Baseball Hall of Fame). Overall, the analyses showed that the
number of pitches thrown in the previous game had an impact on the pitcher’s
performance. As the pitch count increased the pitcher’s earned run average (ERA)
and home runs allowed increased in the next game but the strike-out rate
decreased. Unexpectedly, each pitch during the preceding game was associated
with an incremental decrease in walk rate. The analyses also revealed that with
every day of rest a pitcher had there was a decrease in ERA by 0.06. Overall, the
authors concluded that an increase in pitches thrown in a prior game has a
negative impact on a pitcher’s future performance.

This is an interesting
study suggesting that an increase in the professional pitcher’s workload may influence
his future performance (increased ERA, home runs allowed, etc.). This supports
the more recent trend of restricting pitchers’ pitch counts. While this is the
case for performance, no relationship was assessed to injury rate among
pitchers based on pitch count. Initially, the author’s explained that one
reason for this practice is the prevention of injury. While no attempt was made
in this study to assess a relationship between pitch count and injury this
would be an interesting focus of future research. As the authors pointed out,
the practice of limiting the number of pitches thrown by a pitcher to prevent
injury is sometimes unsuccessful, as in the case with Washington National’s
pitcher Stephen Strasburg who was intended to pitch only a total of 160 innings
in his first professional season, yet required ulnar collateral ligament repair
after only 123 innings. This study highlights that this commonly used strategy
may warrant more research. Tell us what you have seen. Have you had experience
developing a strict pitch count limit for your athletes? If so, do you feel
you see the same trend as the authors’ here (increased pitch count resulting in
decreased performance in the following appearance)?

Written by: Kyle
Reviewed by: Jeffrey

Related Posts:

A Single Bout of Pitching leads to Infraspinatus Activation Deficits 

Bradbury JC, & Forman SL (2012). The Impact of Pitch Counts and Days of Rest on Performance among Major-League Baseball Pitchers. Journal of Strength and Conditioning Research PMID: 22344048