The Silver Slugger is awarded annually to the best hitter at every position, and while the competition is often fierce, this season’s American League catcher showdown is drier than the deserts of Jakku. The big names that fans have grown accustomed to seeing on the leaderboards aren’t putting up eye-popping numbers in 2016: Russell Martin and Salvador Pérez are having subpar years at the plate, Jonathan Lucroy has less than 100 at-bats for the Rangers, and last year’s winner, Brian McCann, isn’t even a starter anymore.

Two surprising candidates have emerged, however. One, of course, is the Yankees’ rookie phenom, Gary Sánchez, whose offensive prowess is actually historic:

The other is Sandy León, the Red Sox’s starting catcher, who leads all AL backstops in fWAR and ranks behind just Lucroy, Buster Posey, J.T. Realmuto, and Wilson Ramos across both leagues. Among catchers with at least 100 at-bats in the American League, León also ranks first with a .350 batting average and second in wRC+, trailing just Sánchez, who has sustained his production over 60 percent as many at-bats as his Boston counterpart.

Those numbers would be eye-popping even in a vacuum, but they’re astonishing given the 27-year-old’s pedigree, or lack thereof. A little more than a year ago, literally any team could have snagged León, who, at the time, looked close to hopeless at the plate as Boston’s backup catcher. Pitchers “love throwing to him,” and he’s thrown out 43.3 percent of potential base stealers in the majors this season, but when he needed to take the hacks himself, he rarely produced more than a squibber to an infielder. Among all hitters with at least 100 plate appearances in 2015, León ranked second-to-last with a wRC+ of 13, ahead of only Pete Kozma. When the Red Sox needed to clear room in July 2015 for hotshot catcher Blake Swihart, León was the logical body to ax from the 25-man roster.

“We liked his defense,” Red Sox general manager Mike Hazen recently told The Boston Globe. “But we took him off the roster and he could have gone anywhere he wanted. Thankfully, he didn’t.”

Though he stayed put, León was an afterthought as recently as spring training, when the Sox appeared to be drowning in capable catchers with Swihart, defensive wizard Christian Vázquez, and veteran Ryan Hanigan on the roster. That changed when Swihart struggled to call a solid game behind the plate, then injured his left ankle playing left field; Hanigan strained his neck; and Vázquez struggled to hit.

So the Red Sox turned to León, who was sitting on their Triple-A roster, but who had hit .184/.238/.202 with two doubles and no homers in 128 plate appearances in the bigs in 2015. Instead of once again hitting like one of the worst players in the sport, though, León made the most of the Sox’s desperation by suddenly hitting like one of the best catchers in baseball. Through 61 games, he’s slashed .350/.408/.553 with seven home runs, 15 doubles, and two triples while continuing to call a good game behind the plate. For every marker except doubles, those figures would represent career highs for León at any level of professional baseball over a full season.

Luck has certainly played a role in León’s success at the plate this year, with his .434 BABIP deviating dramatically from his already-high .344 career mark (.257 before this season). But good fortune hasn’t been the only factor at play. While playing for the Aragua Tigers in the Venezuelan League this past winter, León received advice from Carlos Guillén that changed the way he approaches hitting: “[Guillén] told me to be more aggressive in certain counts and not miss my pitches,” León told the Globe.

It worked: León has improved because he’s making better contact with the baseball. In 2015, his soft-contact percentage was 29.3 percent, while his hard-contact percentage was a mere 14.1 percent. This season, León is making hard contact at a 35.3 percent clip, while his soft-contact mark has dropped to 19 percent. For context, Manny Machado’s hard-contact percentage is 36.2 percent.

That uptick in hard contact has coincided with a rise in León’s z-contact percentage (the percentage of contact a player makes with pitches in the strike zone), which is up from 89 percent last season to 91.9 percent in 2016. And it likewise coincides with a drop in his z-swing percentage (pitches León is swinging at in the strike zone), which dropped from 60.2 percent in 2015 to 56.3 percent this year. In sum: León is hitting the ball harder when he swings, but he’s also more patient at the plate, with his pitches per plate appearance rising from 3.92 in 2015 to 4.30 in 2016.

Though León has cooled off from the July that saw him hitting .355/.375/.581, he’s still performing at a torrid pace. He hit .306/.375/.518 in August and is hitting .350/.435/.400 so far in September. It’s officially more than just a flash-in-the-pan burst, and it’s surprised not just the Red Sox and their fans, but León himself.

“I don’t look at my stats,” León told the Globe. “Sometimes the scoreboard is right in my face and I turn away. I know it’s unbelievable.”

León has been one of the worst and best hitters at the catching position in a short span of time, and now the question becomes where on the spectrum he actually falls. Chalking up León’s success to flukiness or luck ignores the strides he’s made in his approach at the plate, where his exit velocity has jumped from 83.6 mph in 2015 to 87.2 mph this year. Even if León regresses offensively, his defensive prowess should continue to net him opportunities at the major league level.

When we look back at León in a few years, though, it’s completely plausible that this offensive outbreak will be the major outlier on his résumé. It seems inevitable that he’ll come back to earth at some point, and to some degree. But even if he does, it won’t lessen the achievement of a player who posted minus-0.4 fWAR in parts of four seasons emerging as a leading offensive force. And if he can outpace Sánchez, it might not be enough to keep the Silver out of his trophy case, either.