Baseball Glossary › Exit Velocity
Exit Velocity (EV)
Exit velocity (EV) is the speed of the baseball as it comes off the bat, measured in miles per hour by Statcast immediately after contact. It is tracked on every batted ball event, including outs, hits and errors. Harder-hit balls give the defense less time to react, so higher exit velocity generally means more hits and power.
Formula
Worked example (illustrative numbers): five batted balls at 95, 102, 88, 79 and 106 mph.
Sum = 95 + 102 + 88 + 79 + 106 = 470
Average EV = 470 / 5 = 94.0 mph
What to Know
Exit velocity is a skill stat, so MLB describes it as at least somewhat predictive. A hitter with a low batting average but strong exit velocity readings may be a candidate to bounce back, while a hot hitter with weak contact is less likely to sustain it. Pitchers are judged the other way, on exit velocity allowed.
EV vs launch angle: exit velocity is how hard the ball is hit, launch angle is the vertical direction it leaves the bat. Neither tells the full story alone. A 105 mph grounder and a 105 mph line drive are very different outcomes, which is why Statcast combines the two to define its best contact quality.
Exit velocity is also useful context for BABIP: a high BABIP backed by hard contact is more believable than one built on soft contact.
Frequently Asked Questions
What is exit velocity in baseball?
Exit velocity is the speed of the baseball as it leaves the bat, measured in miles per hour by MLB's Statcast system right after contact. It is recorded on every batted ball, whether it becomes an out, a hit or an error.
How is average exit velocity calculated?
Add the exit velocities of all of a player's batted ball events and divide by the number of batted ball events. Five balls totaling 470 mph average 94.0 mph.
Why does exit velocity matter?
A harder-hit ball gives fielders less time to react, so it is more likely to become a hit or an extra-base hit. Because hitting the ball hard is a skill, exit velocity can signal whether a hitter's results are likely to improve or fade.
What is the difference between exit velocity and launch angle?
Exit velocity is how fast the ball comes off the bat. Launch angle is the vertical angle it leaves at. Together they describe a batted ball, and Statcast uses both to identify the most productive contact.
Is exit velocity used for pitchers?
Yes. For pitchers it is called exit velocity against. The best pitchers tend to rank among the league leaders at limiting hard contact, so a low average exit velocity allowed is a good sign.
Who measures exit velocity?
Exit velocity is measured by Statcast, MLB's tracking technology, and published on Baseball Savant along with launch angle and other batted-ball data.
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Sources
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