What is Difficulty of Lift? Definition, Formula, and Example
Difficulty of Lift is a Statcast metric that quantifies how hard a batted ball is to field by combining exit velocity, launch angle, and hang time.
What is Difficulty of Lift?
Difficulty of Lift is a Statcast metric that quantifies the exact challenge level of a batted ball in play. It combines exit velocity, launch angle, and hang time to generate a probability of catch. While catch probability focuses on the outfielder's physical ability to reach the ball, Difficulty of Lift isolates the physics of the batted ball itself. A high difficulty rating means the ball was hit in a way that gives fielders almost no time to react, or requires an extreme physical feat to catch.
How it is Calculated / Measured
Statcast calculates Difficulty of Lift by evaluating the initial trajectory and speed of the baseball off the bat. The metric factors in:
1. Exit Velocity (how fast the ball comes off the bat)
2. Launch Angle (the vertical trajectory of the ball)
3. Hang time (how long the ball is in the air)
4. Horizontal distance from home plate
The metric categorizes batted balls into five-star (95%+ catch probability), four-star, three-star, two-star, and one-star (5% or less catch probability) plays. The formula assigns the highest difficulty to balls hit with extreme exit velocity at low launch angles—often referred to as "lasers" or "screamers"—because they reach the outfield grass in under three seconds, giving fielders zero time to react.
Worked Example
In 2023, Aaron Judge hit a line drive to left-center field with an exit velocity of 113 mph and a launch angle of 14 degrees. Because the ball was hit so hard on a low line, it stayed in the air for just 3.8 seconds. Statcast classified this as a five-star difficulty play, giving the outfielder a catch probability of less than 5%. The hang time was simply too short for a fielder to cover the 290 feet required. Conversely, a fly ball hit by Kyle Schwarber at 92 mph with a 38-degree launch angle hung in the air for 6.5 seconds. Despite traveling 380 feet, the long hang time drops the difficulty rating to a two-star play, giving the outfielder a 90% catch probability.
Why it Matters
Front offices use Difficulty of Lift to evaluate outfield defense. A fielder who routinely converts five-star difficulty plays demonstrates elite sprint speed and route efficiency. Conversely, hitters who consistently produce high-difficulty batted balls are highly valuable, as they generate hits independent of defensive shifting. In fantasy baseball and DFS, understanding a hitter's ability to produce high-difficulty balls helps identify players with high BABIP sustainability.
Limitations and Common Misconceptions
Difficulty of Lift is often confused with catch probability. Catch probability includes the fielder's starting position relative to the ball's landing spot, while Difficulty of Lift strictly measures the batted ball's physical characteristics. A common misconception is that balls hit the furthest are the hardest to catch. In reality, high-arc home runs have a 0% catch probability but are not "difficult" to judge; they are simply uncatchable. The true highest difficulty plays are low-line-drive rockets into the gaps that require instant, perfect reads.
Related Terms
In Legends Deck: We use Difficulty of Lift to calculate defensive ratings on player cards. An outfielder who consistently converts four-star and five-star difficulty plays earns a 99 Fielding rating, directly robbing hits from your opponent during in-game simulations.