Squared-Up Rate

Every combination of bat speed and pitch speed has a physical ceiling for how fast the ball could leave the bat if the collision were mechanically perfect. Squared-up rate compares the actual exit velocity achieved to that theoretical maximum, expressed as a percentage of at-bats where the hitter got close enough to that ceiling to be considered "squared up." It answers a different question than exit velocity alone: exit velocity asks how hard the ball came off; squared-up rate asks how efficiently the swing converted its available speed into ball speed, regardless of how much raw speed was available to begin with.

This distinction matters because a slower swing that consistently squares up the ball can outperform a faster swing that consistently mishits it in terms of results, even though the faster swing would win on a bat-speed leaderboard. A hitter with modest bat speed but a high squared-up rate is getting excellent value from what they have; a hitter with elite bat speed but a low squared-up rate is leaving significant exit velocity on the table through contact-point inconsistency.

Squared-up rate requires bat-tracking or ball-tracking sensor data to calculate precisely, since it depends on knowing both the bat's speed and the pitch's speed at the moment of collision, not just the resulting exit velocity. It is most useful as a swing-efficiency diagnostic layered on top of, not a replacement for, raw exit velocity and hard-hit rate.