Outs Above Average (OAA) is the cumulative effect of all individual Catch Probability plays a
fielder has been credited or debited with, making it a range-based metric of fielding skill that accounts for the number of plays made and the difficulty of them.
For example, a fielder who catches a 25% Catch Probability play gets +.75; one who fails to make the play gets -.25.
Read more about how Outs Above Average works here.
Expected Catch Probability expresses, based on the difficulty of balls hit to the fielder, how many an average outfielder would have caught. Actual Catch Percentage is the actual performance of the particular fielder on those plays. Catch Percentage Added is the difference between the two, showing how much the fielder added (or didn't) based on the opportunities he was presented with.