Bmounds across MLB has been a change aseball is a game of adjustments, and one adjustment occurring on in the distribution of fastballs and non-fastball pitch types.
Beginning in 2019, batters were nearly as likely to see a breaking or offspeed pitch as they were a fastball. That trend has only intensified in the four seasons since, to the point where roughly 47% of pitches thrown thus far in 2023 registered on pitch-tracking systems as two-seam or four-seam fastballs or sinkers.
While all non-fastball pitch types have increased in popularity, one pitch in particular has surpassed the others.
The slider is on a major upswing and has become much more common since 2008, the first season of the pitch-tracking era. This season, sliders are up 8.2 percentage points compared to
