Ultimate Zone Rating (UZR)
Fangraphs uses a less daunting 1,029 words to explain Ultimate Zone Rating (UZR), launched in 2009. Their short explanation refers the reader to five sites, with more words than I wanted to count, providing a more in-depth look at how it works.
The creators of these two metrics agree that they use the same data, but not on much else, as the results are often miles widely divergent.
The Atlanta Braves all-time DRS leader is Andrelton Simmons (113), followed by Jason Heyward (77), Andruw Jones (67), Jeff Francoeur (47), and Rafael Furcal (36). Ender Inciarte is next with 34.
Atlanta Braves’ all-time UZR leader is Andruw Jones (119.6), followed by Jason Heyward (54.1), Andrelton Simmons (53.3), Jeff Francoeur (43.6), with Michael Bourn and Ender Inciarte tied at fifth (17).
Welcome to the StatCast jungle
The debut of StatCast provided sabermetricians more granular data to chew on, and Baseball Savant began providing an advanced outfield defense metric called outs above average (OAA) in 2017. They define OOA as:
"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."
Using a probability implies the use of an average, making it a plus/minus stat like DRS and UZR. More from Baseball Savant.
Data from past catches created catch-probabilities for an average player, based on his location when the play began, and how far he had to go in what direction, to make the catch.
OAA looks cool on the site and works as a range statistic for outfielders, but it doesn’t address the importance of the catch to the game.
Baseball Savant also offers this link to a Mike Petriello post with another 1,325 words and four videos to further explain outfielder OOA.
OAA-outfield was relatively easy to create compared to the intricacies of infield defense, and it took three more years for MLB to roll out OAA-infield.
The designation OAA-infield is mine. It’s essential to separate outfield OAA from infield OAA; while they’re brothers, the two metrics aren’t twins.
Atlanta Braves OAA – Outfield
MLB saw 92 outfielder qualify under OAA-outfield in 2019. Current Atlanta Braves outfielders didn’t rank highly in 2019.
| Catch % | |||||
| Player (Qualified) | Rank | OAA-O | Expected | Actual | Added |
| Ronald Acuna Jr. | 61 | -1 | 89 | 89 | 0 |
| Nick Markakis | 63 | -2 | 87 | 86 | -1 |
| Marcell Ozuna | 80 | -8 | 86 | 83 | -3 |
Ender Inciarte had only 113 chances in 2019. However, he was one of 87 outfielders who qualified in 2018 and ranked second in MLB with 21 OAA-outfield. Adam Duvall qualified as well and tied at #15 with seven OAA-outfield.