There is a new Statcast category this year call “Catch Probability” which evaluates outfield defense (MLB.com; look for more coming on that. What Nats have appeared on the Statcast Leaderboard?
In 2016, the only NATS were: Ryan Zimmerman, 14th on the list for Average Exit Velocity with 94.1 mph (284 events) and Anthony Rendon at 47th with 92.6 mph (388 events). And, on the Longest HR list: Ian Desmond, 34th with a distance of 462 feet off Deolis Guerra (Angels) on July 19, 2016 2016, and Bryce Harper, 39th with 461 feet off Christian Bergman (Rockies) on Aug 17, 2016.
In 2015, HR distance leaders included Ian Desmond 13th with 477 feet off Jake Peavy (Giants) on Aug 15, 2015, and Bryce Harper 46th with 461 feet off Aaron Harang (Phillies) on Apr 18, 2015. Batting Exit Velocity lists Stephen Strasburg as 2nd with 121.3 mph in a single off of Eddie Butler on Aug 8, 2015, and Bryce Harper at 30th with 116.0 in a single off of Rubby De La Rosa (Diamondbacks) for a double on May 7, 2015. Ryan Zimmerman was on the Average Exit Velocity at 38th with 92.1 mph in 264 events. Blake Treinen appears on the Average Pitch Velocity twice: 33rd with a 97 mph two-seam FB (90 events) and 40th with a 96.8 sinker (587 events).