How Different Counts Affect Fastball Velocity

Have you ever noticed that good pitchers seem to reach back for a little extra velo when they need it?  This blog post will look at the top 20 starting pitchers by average fastball velocity. I chose starting pitchers because they have to pace themselves throughout a game more than relievers so I expected to see clear differences in velocity between pitch counts.

As expected, the counts in which the pitcher has yet to throw a strike were the slowest fastball speeds.  This is because, with the risk of walking the batter, the pitchers took a little bit off of their fastballs in hopes to gain accuracy.  The pitches with the fastest fastball speeds are those in which the pitcher had 2 strikes on the batter already to try and put the hitter away via strikeout. 

Of these pitchers, the largest difference between pitch speeds was 4 mph with Robert Stock’s 3-0 fastball (93.7) and 0-2 fastball (97.7).

The largest difference between (0-0) and (0-2) was Shane McClanahan with a 2mph difference.

The smallest difference between all the pitches was Luis Castillo who had only a 0.9 mph difference between his fastest count (3-2) and slowest count (0-0).

These 20 pitchers average 96.9 mph on their fastball, but still are able to take it to another level. Overall they increase their average to 97.7 mph in 1-2 counts. Next time you notice an uptick in velocity from a pitcher in a 2-strike count, know that it was not accidental and actually pretty common for pitchers to reach back for a little extra juice.