Happy Rafael Devers Day!

The highly-touted 20-year-old is slated to make his big-league debut tonight, and will almost certainly provide Boston with a sizable upgrade at the hot corner. Devers slashed .300/.369/.575 at Double-A before hitting a cool .400/.447/.600 in a nine-game stint at Triple-A.

Devers’ biggest strength is his power. After putting up middling power numbers in years past, he smacked 20 homers and 20 doubles in the minors this year. Unlike many power hitters, Devers doesn’t strike out a ton — he’s kept his strikeout rate below 20% throughout his time in the minors.

Devers has quite an exceptional offensive profile, but it’s even more impressive when you consider he’s much more than his hitting. Not only does Devers play one of the more premium defensive positions, but he plays it quite well. He’s been three runs above average at third base this year by Clay Davenport’s numbers, and checked in at +19 (!) runs last year in High-A. Devers’ high-minors performance has been excellent across the board, which is all sorts of encouraging coming from a 20-year-old.

My KATOH system pegs him Devers 11.7 WAR over his first six seasons by the stats-only method and 15.3 WAR by KATOH+, which incorporates his Baseball America ranking. Those marks place him sixth and fourth, respectively, among prospects.

To put some faces to Devers’ statistical profile, let’s generate some statistical comps. I calculated a Mahalanobis distance between Devers’ 2017 performance and every season since 1991. In the table below, you’ll find the 10 most similar seasons, ranked from most to least similar. The WAR totals refer to each player’s first six seasons in the major leagues. 

Please note that the Mahalanobis analysis is separate from KATOH. KATOH relies on macro-level trends, rather than comps. The fates of a few statistically similar players shouldn’t be used to draw sweeping conclusions about a prospect’s future. For this reason, I recommend using a player’s KATOH forecast to assess his future potential. The comps give us some interesting names that sometimes feel spot-on, but they’re mostly just there for fun.