In Game Velocity Changes – When Fatigue Attacks
Velocity changes between seasons, or even games, are well reported on thanks to Jeff Zimmerman’s velocity tracking document.
Fastball Velo changes, ’16 adjusted up
C Anderson +2.4
Estrada +1.8Cain -3.2
Santiago -2.8
Adleman -2.4https://t.co/Qr33MW0GYN— Jeff Zimmerman (@jeffwzimmerman) June 7, 2017
Velocity is very important to the success of pitchers – as I’ve written about with respect to my Stuff metric, and as highlighted in this great article by Mike Fast from 2010, every little bit of velocity matters. Within pitchers – those who lose velocity become shells of their former selves – like Eno Sarris wrote about Matt Harvey before this season started. While a Velocity drop between games is an indicator that someone might be hurt, a velocity drop within a game might indicate that a pitcher is becoming fatigue – a big sign of possible future injury.

