Complete game

A converted shortstop, Justin Upton has become one of the best right fielders in the game. Cary Edmondson/US Presswire

A version of this story appears in the Sept. 19 issue of ESPN The Magazine.

When the Arizona Diamondbacks asked Ryan Roberts to play outfield during his first season with the club in 2009, the former utility man immediately sought out Justin Upton, the club's cornerstone, for some fielding advice. Roberts was surprised by Upton's guidance, which basically consisted of "see ball, catch ball, throw ball."

This year, Upton's insight on the game is far more nuanced. He can be seen telling his fellow outfielders how to position themselves based on the count -- with two strikes, the batter is less likely to pull -- and instructing them on throws to set their feet with their glove to their side in order to maximize accuracy.

"Guys become great when they figure out the little things: their routes in the outfield, their arm strength, what works for them at the plate and on the bases," says Roberts, who has settled in as the D-backs' third baseman. "That's when they adapt to being all-around players."