What is Exit Velocity? Definition, Formula, and Example
Exit velocity is the speed of the baseball as it leaves the bat, measured in miles per hour by the Hawk-Eye tracking system in every MLB stadium. It is the cleanest measurement of raw contact quality and the single largest input into modern hitter evaluation.
What Is Exit Velocity?
Exit velocity (EV) is the speed of a baseball at the moment of bat-ball contact, measured in miles per hour. Statcast's Hawk-Eye optical tracking system captures it on every batted ball in every MLB game, with precision within a fraction of a mph.
There are three relevant aggregations:
- Max EV — the hardest-hit ball a hitter has produced. Best single-number measure of raw power ceiling.
- Average EV — the mean across all batted balls. Removes noise but is pulled down by mishits.
- Hard-Hit% (HardHit%) — the share of batted balls hit at ≥95 mph. Most predictive of sustainable production.
The Numbers That Matter
League averages (2024):
| Metric | MLB avg | Elite (90th %ile) | Generational (99th %ile) |
|---|---|---|---|
| Avg EV | 88.5 mph | 91.5 mph | 94.5+ mph |
| Max EV | 108 mph | 113 mph | 118+ mph |
| Hard-Hit% | 40% | 51% | 60%+ |
The hardest-hit ball on record is Oneil Cruz at 122.4 mph (2022). Aaron Judge, Giancarlo Stanton, and Shohei Ohtani live in the 93+ mph average EV tier — a group of maybe 10 hitters per season.
Why Exit Velocity Matters
Run-scoring correlation. For every 1 mph increase in a league-wide average EV, offensive production rises measurably. The correlation between individual hitter EV and wOBA is one of the strongest relationships in baseball analytics.
Injury proxy. Drops in average EV often precede hitter decline or point to a hidden injury. Front offices monitor rolling 30-day EV; a 2 mph drop vs. season baseline is a red flag.
BABIP anchor. A hitter who's hitting .320 BABIP but averaging 87 mph EV is regressing. A hitter at .265 BABIP with 92 mph EV is getting unlucky. EV tells you which of those two numbers is the real one.
Worked Example
A hitter in April puts 78 batted balls in play. His EV distribution:
- 32 balls at 95+ mph → Hard-Hit% = 41%
- Sum of EVs = 6,942 mph → Avg EV = 89.0 mph
- Single hardest: 114 mph → Max EV = 114 mph
This profile is slightly above league average on Hard-Hit% and Avg EV, with an elite Max EV that suggests his power ceiling is higher than his rate stats show so far. Front-office read: "real raw power, but we need to see the Avg EV climb into the low 90s before we pay for it."
Exit Velocity ≠ Barrel
This is the single most common mistake. A ball hit at 115 mph into the ground is a 115 mph groundout — still a groundout. Exit velocity without the right launch angle does not produce home runs. The barrel metric exists precisely because EV alone isn't enough.
The cleanest way to think about it: EV is the *fuel*. Launch angle is the *trajectory*. You need both to score.
Exit Velocity in Legends Deck
Every card's "Contact Strength" and "Max Power" ratings map directly to Avg EV and Max EV percentiles respectively. When a Legends Deck card has 98 Contact Strength, that's telling you the player's real Avg EV is in the 98th percentile of MLB. In the sim engine, this means the card hits the ball harder on average, producing more line-drive rate and fewer soft-contact outs.