Exit Velocity, Launch Angle and Barrels Explained
How Statcast measures batted balls, what exit velocity, launch angle, hard-hit rate and barrels mean, how they fit together, what they leave out, and how home runs rose across the launch-angle era.
Every ball a hitter puts in play now carries two numbers: how fast it left the bat, and at what angle. Exit velocity is the speed, in miles per hour, and launch angle is the vertical direction, in degrees above or below horizontal. Together they predict, better than almost anything a scorer can see, whether the ball is likely to be a single, a double, a home run or an out. A third term, the barrel, labels the combinations of speed and angle that have historically produced the best results.
This article defines each term, shows how the two measurements work together, and explains where they come from. It works through a physics rule of thumb with an example, uses historical data to show how home runs changed after tracking arrived, and is plain about what these numbers cannot tell you. The thresholds quoted are the ones MLB has published; the league's own glossary is the place to check for any updates.
Where the numbers come from
Statcast, MLB's tracking system, was introduced in all 30 ballparks in 2015. In its first seasons it combined Doppler radar with cameras; beginning with the 2020 season, MLB moved to an optical system built around Hawk-Eye cameras. Either way, the system tracks the ball from the pitcher's hand to the point where it is caught or lands, and from that track it computes the speed and direction of the ball immediately after contact.
Two limits follow. First, there is no Statcast data before 2015, so exit velocity and launch angle cannot be compared with players from earlier decades. The historical record, which the rest of this site uses for history, has no batted-ball measurements at all. Second, tracking is not perfect: a ball hit very softly, or a bunt, may not be measured, and the accuracy of any single reading is limited. Statcast numbers are best read across hundreds of batted balls, not one.
Exit velocity: how hard the ball leaves the bat
Exit velocity is the speed of the ball just after it leaves the bat, measured in miles per hour. It is the most direct measure of contact quality. A ball hit harder gets to the fielders sooner, is harder to catch and, in the air, travels farther. Hitters try to maximize it, and the pitch does less to determine it than most fans expect.
A standard rule of thumb from the physics of collisions says that the speed of a ball off the bat is roughly 0.2 times the speed of the incoming pitch plus 1.2 times the speed of the bat at the point of contact. The coefficients are approximations; they change with where on the bat the ball is hit, the bat's weight and the ball itself. But the pattern they show is the useful part.
Take two examples. A hitter swinging a bat at 70 miles per hour that meets a 95-mile-per-hour fastball produces about 0.2 times 95 plus 1.2 times 70, or 19 plus 84, which is 103 miles per hour. The same swing against an 85-mile-per-hour slider produces 17 plus 84, or 101. A 10-mile-per-hour drop in pitch speed costs the hitter only about two miles per hour of exit velocity. Now change the swing instead: speed the bat up from 70 to 75 and the same fastball produces 19 plus 90, or 109. Five more miles per hour of bat speed adds six to the exit velocity.
The lesson is that bat speed and the quality of contact drive exit velocity. That is why training programs for hitters emphasize swing speed, and why a hitter's strength matters more than the speed of the pitches he faces. It is also why exit velocity can be used to scout hitters: the number is a property of the hitter more than of any single pitch.
Launch angle: the direction of the ball
Launch angle is the vertical angle at which the ball leaves the bat, measured in degrees. Zero degrees is a ball hit on a perfectly flat line; a positive angle is upward and a negative angle is downward. MLB groups batted balls into four standard categories by angle:
| Category | Launch angle | What it usually produces |
|---|---|---|
| Ground ball | Below 10 degrees | Outs on the infield unless hit hard or placed well; rarely extra bases |
| Line drive | 10 to 25 degrees | The highest rate of hits of the four categories |
| Fly ball | 25 to 50 degrees | Outs on average, but the path to most home runs |
| Pop-up | Above 50 degrees | Almost always an out |
A related label is the sweet spot, the range of launch angles from 8 to 32 degrees. Batted balls in that range have produced the best results, averaged over all exit velocities, because they stay in the air long enough to clear infielders and not so long that outfielders can catch them. A ball hit in the sweet spot is not guaranteed to fall, only more likely.
Launch angle alone does not say whether a hitter is good. A hitter with a high average angle hits many fly balls and gets home runs but also many fly-ball outs. A hitter with a low average angle hits more grounders, which helps a fast runner collect infield hits but costs him power. The measurement makes sense only alongside speed.
Putting speed and angle together
A hard-hit ground ball and a soft fly ball are both usually outs. A hard-hit line drive and a hard-hit fly ball at the right angle are usually not. The two measurements combine into a map: for any exit velocity there is a range of angles that produces good results, and the range gets wider as the ball is hit harder.
Hard-hit is a simple version of the idea. MLB counts a batted ball as hard-hit when its exit velocity is 95 miles per hour or more, and a hitter's hard-hit rate is the share of his batted balls that meet that mark. It ignores the angle, so a 100-mile-per-hour ground ball counts equally with a 100-mile-per-hour line drive. That is the main weakness of the statistic, and the reason a hitter with a high hard-hit rate can still have a modest batting average if he hits the ball into the ground.
The more complete version is the family of expected statistics, which estimate what a batted ball should produce based on its speed and angle, and for some measures its direction, and compare it to what actually happened. They are covered in expected statistics: xBA, xSLG and xwOBA explained.
The barrel: the best combination of speed and angle
A barrel is a batted ball whose combination of exit velocity and launch angle has historically produced at least a .500 batting average and a 1.500 slugging percentage. In other words, it is the kind of contact that, on average, gets a hit about half the time, and when it does, produces extra bases: home runs, doubles and triples.
MLB's definition has two parts. The minimum exit velocity for a barrel is 98 miles per hour. At that speed, the launch angle must be between 26 and 30 degrees. As the ball is hit harder, the range of acceptable angles widens: at 99 miles per hour the zone is a degree or so wider on each side, and it keeps widening at each additional mile per hour, until at the very top of the scale it is roughly 40 degrees wide. The shape of the zone is a wedge that opens as exit velocity increases.
| Exit velocity | Barrel launch angle (approximate) |
|---|---|
| 98 mph | About 26 to 30 degrees |
| 100 mph | A wider band, roughly 24 to 33 degrees |
| Highest speeds | A very wide band, from 8 to 50 degrees |
The table's first row is MLB's published threshold; the others are approximations that show the pattern. Readers who want the exact boundary for any speed should use MLB's glossary.
Two statistics come from the definition. Barrel rate, or barrels per batted ball event, is the share of batted balls that are barrels. Barrels per plate appearance divides by plate appearances instead, which also accounts for strikeouts and walks. Both rank hitters by how often they produce the best contact, and both correlate strongly with home-run production. A hitter who barrels the ball often, and who is not unusually unlucky on balls in play, tends to be a hitter with power.
The launch-angle era in the historical numbers
The arrival of tracking coincided with one of the biggest changes in how hitters approach the game. After 2015, hitters and coaches who could now see launch angle began deliberately swinging upward, trying to lift the ball rather than hit it on a line or on the ground. The combined results are in the historical record, which records league home runs and strikeouts for every season through 2025:
| Season | Home runs | Home runs per team-game | Batting average |
|---|---|---|---|
| 2014 | 4,186 | 0.86 | .251 |
| 2015 | 4,909 | 1.01 | .254 |
| 2017 | 6,105 | 1.26 | .255 |
| 2019 | 6,776 | 1.39 | .252 |
| 2022 | 5,215 | 1.07 | .243 |
| 2025 | 5,650 | 1.16 | .245 |
From 2014 to 2019, home runs rose by nearly two thirds, from 4,186 to 6,776, while league batting average barely moved (.251 to .252). Strikeouts also climbed, from about 7.7 per team-game in 2014 to about 8.8 in 2019 by the same measure. Hitters were trading contact for power, and the trade worked in the sense that scoring rose from 4.07 runs per team-game in 2014 to 4.83 in 2019.
Swing changes were not the only cause. Scientists commissioned by MLB reported in 2018 and 2019 that changes in the aerodynamics of the baseball had reduced drag and contributed to the increase in home runs, and the league later adjusted the ball and its handling. The decline from 6,776 home runs in 2019 to 5,215 in 2022 coincided with changes the league made, including the storage of baseballs in humidors in all 30 parks beginning in 2022. The takeaway is that exit velocity and launch angle describe the batter's contribution, but the ball, the park and the weather also affect where it lands.
What these numbers cannot tell you
Several things are missing from any exit-velocity or barrel chart.
- Direction. A 105-mile-per-hour fly ball to the deepest part of the park and the same ball to the shortest part of the park have different outcomes. Spray angle matters, and parks differ in size and wind.
- Park and weather. Air density changes how far a ball carries. A ball that is a warning-track out in a cool, humid park may leave the yard in a hot, dry one.
- Defense. The same ball is a single against one outfield and an out against another. Methods such as outs above average, covered in defensive metrics explained, look at the fielder's side.
- Speed. A slow ground ball is an out for a slow runner and a hit for a fast one. Sprint speed and baserunning metrics explain how that is measured.
- Pitch quality. A hitter who barrels meatballs and swings through everything else has a different profile from one who handles every pitch.
- Swing decisions. Contact quality says nothing about whether a hitter chases pitches outside the zone or takes strikes.
None of these makes the measurements less useful, only less complete. A hitter's batted-ball profile is a description of what happens when he makes contact, and it must be paired with data on how often he makes contact and which pitches he swings at.
How to read a hitter's page
A reasonable way to use these numbers is as a layered check. Start with results: batting average, on-base percentage and slugging percentage. Then look at contact quality: average exit velocity, hard-hit rate and barrel rate. A gap between the two sets of numbers is the interesting part.
If a hitter's results are poor and his contact quality is strong, he may have been unlucky and may improve, a situation the expected statistics are designed to highlight. If his results are strong and his contact quality is weak, he may be due for a decline. In both cases sample size matters. Contact-quality measures generally settle down faster than outcomes such as batting average, but even they need a few hundred batted balls to be reliable, and a single month proves little. The ideas are laid out in sample size and regression to the mean.
Age matters as well. Hitters generally lose bat speed as they get older, and exit velocity falls with it; how quickly depends on the player. To see how skills change over a career, read aging curves in baseball.
Common mistakes
- Treating hard-hit rate as a measure of power. It ignores angle. A hitter can have a high hard-hit rate and very few home runs if he hits the ball into the ground.
- Judging a hitter on one swing. A single 115-mile-per-hour batted ball is a highlight, not a skill. The average over a season is the signal.
- Assuming a higher launch angle is always better. The best results come from the right angle for the speed, and a fly ball with a low exit velocity is simply an out.
- Comparing across eras. Statcast started in 2015. A claim that a player of the 1950s hit the ball harder than one today cannot be tested.
- Forgetting the park. A barrel in one ballpark is a home run; in another it can be a long out.
Common questions
What is a good exit velocity? It depends on the context. Rankings by season are published on MLB's Baseball Savant site, and the useful comparison is a hitter's average against the league's, not any single threshold.
What is a barrel? A batted ball with a minimum exit velocity of 98 miles per hour and a launch angle in a range that widens as speed increases, beginning at 26 to 30 degrees at 98 mph. It marks the combinations that have historically produced at least a .500 average and a 1.500 slugging percentage.
What counts as a hard-hit ball? One with an exit velocity of 95 miles per hour or more.
What is the sweet spot? The range of launch angles from 8 to 32 degrees, in which batted balls have produced the best results.
Does the pitch speed matter for exit velocity? Slightly. By the rule of thumb above, 10 miles per hour of pitch speed changes exit velocity by about two miles per hour, while 5 miles per hour of bat speed changes it by about six.
Where to go next
If you like the idea of measuring contact, a classic hitting feat gives a useful contrast: read Joe DiMaggio's 56-game hitting streak, which has no batted-ball data at all, only results. For October baseball, see how the MLB postseason works, and to browse leaderboards or compute rate statistics yourself, use the site's leaders page and stat calculator.