PITTSBURGH -- How did Andrew McCutchen stack up among center fielders last year? What makes Starling Marte such an elite defender? How is Gregory Polanco developing in the outfield?
In this era of statistical enlightenment throughout baseball, defensive questions remain the most difficult to answer. But with the advent of MLB's Statcast™ tracking technology, the game has been flooded by more concrete data about outfielders' route-running, speed, reaction time and more.
Statcast™ has provided catch rates, based on a combination of hang time and distance from the ball. While it's only one evaluative tool, it enables us to better determine how adept outfielders are in a few areas without watching every single play. What kind of range have they displayed? Are they making the plays they should make? How often do they make the tough, highlight-reel catches?
It's no secret McCutchen is coming off the worst defensive season of his career, recording minus-28 Defensive Runs Saved and a minus-18.7 Ultimate Zone Rating, both last among qualified outfielders. Through Statcast™'s tools, we can compare his work to two other center fielders, Baltimore's Adam Jones and Philadelphia's Odubel Herrera.

McCutchen played 1,318 innings in center, Herrera (six DRS, 3.9 UZR) logged 1,301 1/3 and Jones (minus-10 DRS, minus-10.1 UZR) finished with 1,300. The above charts show the hits that fell within their ranges. One key difference to note is the number on plays deemed "easy" or "routine." McCutchen allowed 11, whereas Herrera permitted eight and Jones only let two such balls drop.
Granted, McCutchen's shallower positioning may play a part in this evaluation, which accounts for hang time and distance but not direction. A play might be "easy" or "routine" coming in on the ball but more difficult when running back or, for example, trying to make a play at the wall. Advanced defensive metrics are more likely to punish a player for permitting a deep extra-base hit than a bloop single, as doubles and triples are more likely to lead to runs scored.

On the other end of the spectrum, Herrera made more "tough" or "highlight" plays than either, though McCutchen still made 30 such catches compared to Jones' 25.
Then there is Marte, a two-time Gold Glove Award-winning left fielder widely considered one of the game's best defensive outfielders.

Marte allowed a handful of hits on "easy" or "routine" plays, but another chart shows that the range of balls he caught was actually larger than the area in which they fell in for hits. Marte's rocket right arm is a big part of his game -- he led the National League with 17 outfield assists -- but his range is remarkable compared to most other left fielders.

Polanco rounds out the group in right field. The Pirates have praised his growth as an outfielder, particularly the way he's learned to handle balls off or near the 21-foot Clemente Wall behind him. Polanco graded out above-average according to DRS (four, seventh in the Majors among qualified right fielders) and UZR (5.9, sixth) but he isn't as flashy or highly regarded as Marte.

The above charts show Polanco made 29 catches considered "tough" or "highlight," but perhaps more impressive is he allowed only one "easy" hit -- even that one was borderline -- and four "routine" hits. The gold standard in that category might be Cubs outfielder Jason Heyward, who didn't misplay a single "easy" or "routine" ball all season.