In a late-April game against the Angels with a runner on first, two outs in the sixth inning, and the score tied 4-4, Yankees starter Masahiro Tanaka aimed a 92 mile per hour fastball toward the outside part of the plate. The pitch met its target: Although the TV camera angle shows it landing slightly outside, Pitch Info’s data shows that, based on factors like the 3-1 count and La Stella’s left-handed hitting stance, this throw had an 87 percent chance of being called a strike.

Most catchers, in other words, would have secured this strike and forced La Stella into a full count. But Gary Sánchez couldn’t; the umpire didn’t budge, and La Stella took first base. The missed opportunity would prove costly. Tanaka exited the game after the walk, and reliever Jonathan Holder allowed both inherited runners to score and break the tie. The Angels went on to win the game—New York’s only loss in a 10-game stretch.

Sánchez more than made up for his subtle defensive miscue at the plate in the week to come. In his next game, in San Francisco, he clubbed a grand slam in a Yankees win; he homered the next day, too, and hit three more the following weekend against Minnesota. Overall, the Yankees backstop is tied for second in the AL in home runs, with 19, and leads all everyday catchers with a .260/.333/.624 batting line. But that dichotomous week illustrates a broader and more tenuous balance in his game: Sánchez adds tremendous value at the plate, but he’s giving plenty back behind it.

To discuss Sánchez’s performance this season, the place to start is his offense, where he has more than rebounded from a desultory 2018 campaign. He never found his typical rhythm last season and hit just .186 with a .291 on-base percentage. He skied oodles of infield pop-ups; he didn’t reach 20 home runs; he hit a combined .139 with 41 strikeouts and just two home runs against curveballs and sliders, according to Brooks Baseball.

He’s back to his usual slugging self this season, though, and it’s not hard to figure out why. Sánchez’s 2019 offensive profile isn’t perfect—he’s striking out more than ever—but when he makes contact, it’s the right kind of contact, and his results soar along with the pitches he crushes toward the outfield bleachers.

Hit the ball hard and in the air, and extra-base hits will follow. The chart below shows every hitter in 2019 with as many plate appearances as Sánchez and a ground-ball rate below 30 percent. They have almost all been well-above-average hitters, with an average weighted wRC+ of 150, meaning they have collectively hit 50 percent better than league average.

2019’s Lowest Grounder Rates Player Ground Ball % wRC+ Player Ground Ball % wRC+ Jay Bruce 23.1 130 Gary Sánchez 23.5 147 Jorge Polanco 24.3 152 Daniel Vogelbach 25.5 150 Cody Bellinger 27.7 193 Matt Carpenter 28 97 Joey Gallo 28.4 169 Rhys Hoskins 28.7 134 Byron Buxton 29.1 120 Anthony Rendon 29.3 170 Mike Trout 29.6 187 Brandon Belt 29.9 127

Sánchez’s offensive advantage is especially potent at his position, whose defensive demands typically give it the worst offensive output of any spot on the field. The catcher record for most home runs in a season is 45, set by Johnny Bench in 1970. Sánchez has 19 homers in 64 team games, putting him on pace for 48 this year—and even that number might undersell his potential, because he missed two weeks in April to a calf strain. Accounting for his time on the injured list, Sánchez is on pace for 54 homers. Even in a season of home-run-record chases, that’s an outrageous gap between first and second place.

His defense, however, has been far more underwhelming. Before this season, Sánchez as a defender was best known for his struggles with pitch blocking. In 2017, he ranked 71st out of 73 catchers (minimum 1,000 pitches received) in Baseball Prospectus’s “blocking runs” metric; in 2018, he ranked 81st out of 82.

Although poor blocking can grate on viewers and generate grisly lowlights, it isn’t nearly as harmful as its overt visibility might suggest. Even in those seasons, Sánchez’s blocking cost the Yankees just three or four runs over the whole year. With a rocket arm—he ranks second among catchers in average pop time this season—and solid pitch framing, Sánchez more than compensated for his occasional lapse on a pitch in the dirt. His overall defensive performance still rated near average, or better.

But 2019 has told a different story. Here’s the frightful tale in graphical form. (To better illustrate change, we’ve adjusted all seasons to a rate basis of runs saved or allowed per 1,000 innings caught.)

Sánchez has improved his blocking this year, almost to league average. But his ability to properly frame pitches—or present edge-of-the-zone pitches as strikes—has seemingly collapsed, dragging his overall defensive value down with it. Where a catcher with blocking issues sees that difficulty manifest just a few times in a game, at worst, a catcher with framing issues must contend with that trouble on dozens of pitches per game. And those small problems compound; through less than half the season, Sánchez has already cost New York 6.7 runs with his framing—making his past blocking troubles look insignificant by comparison.

The numbers show that Sánchez is struggling in all aspects of pitch framing this season. StatCorner ranks him third-worst (among catchers who have received at least 2,500 pitches) in both percentage of pitches outside the zone that he steals for strikes and percentage of pitches inside the zone that he turns into balls with poor presentation.

BP rates Sánchez 48th out of 50 qualifying catchers in framing runs this year. Behind him is the Cubs’ Willson Contreras—a notoriously awful framer who, like Sánchez, is trading elite offense for subpar defense—and the Rangers’ Isiah Kiner-Falefa, who deserves some kind of asterisk because he is in the process of converting from a utility infielder to a catcher after scarcely playing the position earlier in his career.

Here’s one way to demonstrate just how much Sánchez’s defensive numbers are pulling down his offensive advantage. A comparison between Sánchez and Reds catcher Tucker Barnhart seems, at first, extraordinarily lopsided. The Yankees catcher is hitting hordes of home runs; Barnhart is batting .197/.294/.331. But Barnhart has jumped from a below-average framer in the past to a positive one this season, so their overall values converge: BP lists both Sánchez and Barnhart with the same wins above replacement player total this season, tied for 10th among all catchers.

This kind of analysis might be an overreaction to a relatively small sample. It’s possible that as teams have become better at teaching their catchers how to frame, the league as a whole is improving, and thus increasing the amount of random volatility in the numbers. Consider the rise of the Twins’ catchers, for instance, or that of new Phillies catcher J.T. Realmuto, who had been worth negative-14.2 framing runs in his career before this season but has rated among the best in baseball thus far in 2019. That improvement has led BP to rate him as the most valuable catcher in the league this year, even though his batting production has slowed. And if his defensive value is increasing relative to the league average, then someone’s has to drop on balance.

After the 2017 season, then–FanGraphs writer Jeff Sullivan observed that framing’s predictability had shrunk compared with earlier in the decade. “The year-to-year relationships are disintegrating,” he wrote about pitch framing values. “A good framer in [Year 1] was still likely to look like a good framer in [Year 2], but that couldn’t be said with very much confidence. The data is getting increasingly random.”

Perhaps, then, Sánchez is merely going through a cold spell; perhaps he’ll rebound in the second half and boost his numbers back toward the league’s midpoint. He has, to his credit, made significant strides with his blocking—no small feat when receiving pitches from the likes of Adam Ottavino, Zack Britton, and Aroldis Chapman on a regular basis. On a per-inning basis, Sánchez has halved the number of pitches he’s allowed to bounce away compared with last season.

Gary Sánchez Blocking Numbers (Per 1,000 Innings) Season Passed Balls Wild Pitches Combined Season Passed Balls Wild Pitches Combined 2016 19 47 66 2017 18 60 78 2018 28 69 96 2019 13 34 47

Yet he still embodies a strange statistical profile overall. Last year, Sánchez couldn’t block and he couldn’t hit, but he could at least frame; this year, he’s seemingly flipped all three. And while his framing regression is reason for concern this season, his ability to, at various points, succeed in all prominent phases of a catcher’s job gestures at the tantalizing potential he still possesses—after all, he’s still a pre-arbitration player who just recently passed 300 career games. A Sánchez who can homer and block and frame would be the best backstop in baseball. He’s two-thirds of the way there now, but that last bit matters on every pitch he receives.

Stats through Sunday’s games.