EV against
Average exit velocity the pitcher allows (mph).
What EV against means
The pitcher-side view of exit velocity: how hard hitters square this arm up. Lower is better, and unlike ERA it is largely independent of the defense behind him.
What counts as a good EV against
Lower is better — roughly 90 is poor, 88.5 average, 87 good, and 85.5 or better elite.
Also written
exit_velo_against · avg_ev_against · ev_a · EV-a · avg_ev_ag
Source
Statcast