Catch Probability
Definition
Catch probability represents the likelihood that a batted ball to the outfield will be caught, based on four important pieces of information tracked by Statcast:
- How far did the outfielder have to go? ("Distance needed")
- How much time did he have to get there? ("Opportunity time")
- What direction did he need to go in?
- Was proximity to the wall a factor?
Accordingly, each tracked batted ball to the outfield is assigned a catch probability, which reflects how often outfielders have made the catch on comparable plays in the Statcast era.
The more time a fielder has to react to a ball, and the less distance needed to reach it, the higher (easier) the catch probability. The less time a fielder has to get to the ball, and the more distance he needs to cover to make the play, the lower (more difficult) the catch probability.
Distance needed (the distance the outfielder needs to travel from his starting position, with an optimal route, to make the catch) is used instead of distance covered (which measures the distance a fielder actually travels from the point the ball is struck to the time the play is made) to prevent fielders from receiving additional credit for taking longer-than-necessary routes to the ball.
Meanwhile, opportunity time is calculated from the point the ball leaves the pitcher’s hand (rather than when the batter makes contact) to credit instances in which a fielder makes a read prior to the ball being hit, such as adjusting his position based on where the catcher sets up or what type of pitch is called.
You can see how distance needed and opportunity time translate to catch probability in this interactive chart.
Updates to catch probability
• As of May 2017, Catch Probability began to account for fielding direction, with plays where an outfielder needs to travel in the opposite direction of home plate (colloquially described as “going back on the ball”) receiving an adjustment to account for their relative degree of difficulty.
For the purpose of determining what counts as “going back on the ball,” the 360 degree range around each fielder is divided into six 60-degree sections, where 0 degrees is always toward home plate and 180 degrees is always straight back. The zone defined as “going back” is 30 degrees to the left and right of the 180 degree line.
• As of 2018, Catch Probability accounts for the extra difficulty of plays made at or near the wall.
• As of 2019, Catch Probability plays are reported in five percent bands -- so 5%, 10%, 15%, etc. There’s no functional difference in a 21% play vs. a 22% play, for example, and showing catch probability by every 1% implied a level of precision that probably isn’t there. The best catches are now a catch probability of 5%.
Why it’s useful
Catch probability attempts to quantify outfield defense by measuring the difficulty of a particular catch. Though two different catches are marked the same way as outs in the scorebook, a different amount of skill is required to catch a lazy fly ball as opposed to a sinking liner. Instead of relying on the eye test, fans can use catch probability to credit that difference in difficulty accordingly.
Statcast also divides outfield plays into five “star ratings” representing their difficulty level, based on each play’s catch probability:
- 5 Stars – 0-25% catch probability
- 4 Stars – 30-50%
- 3 Stars – 55-75%
- 2 Stars – 80-90%
- 1 Star – 95%
(Plays with a catch probability higher than 95% don’t merit a star rating.)
Here’s one example of what makes catch probability such a valuable defensive metric …
The video below compares two plays by two different center fielders: one by Pete Crow-Armstrong for the Cubs in 2025, one by Matt Vierling for the Tigers in 2023.
Crow-Armstrong and Vierling both needed to cover 52 feet in 3.3 seconds of opportunity time -- meaning their catch probabilities were an identical 10%. But only Crow-Armstrong, an elite defensive center fielder, was able to get to the ball in time to make the catch. He got such a good jump on the ball that he was able to make the catch without even having to dive. Vierling, on the other hand, couldn’t quite get there in time and had to let the ball fall for a base hit.
Crow-Armstrong’s catch was an incredibly difficult play, one which most MLB outfielders don’t make, but you might not be able to tell just by watching it. Catch probability shows us what the eye test can't.
Catch probability leaderboards
Statcast’s catch probability leaderboard, showing the outfielders with the most catches at each star rating, can be found here.
The Outs Above Average leaderboard for outfielders, which converts the catch probabilities of all of an outfielder’s plays made/missed into a statistic measuring their range, can be found here.