When I click over to the leaderboards, I see that, right now, Jose Altuve is the major-league leader in wOBA. Which means that, by that measure, Altuve has been baseball’s best hitter, which is absolutely nuts. Not that we didn’t know Altuve was good, but he’s having a Mike Troutian season. Altuve is simultaneously breaking down pitchers and breaking down barriers, and it’s just so much more fun to have him leading the stat than some ordinary muscle-bound giant. It makes us second-guess what’s possible. Lots of things are possible.

Like this. When I click over to the leaderboards, and then significantly drop the minimum number of plate appearances, I see that, right now, the major-league leader in wOBA is Sandy Leon. Unlike Altuve, Leon’s offensive season isn’t “qualified.” So we can’t take it close to so seriously. But you might not understand how ridiculous this is, and you might not understand how critical it’s been for a Red Sox club trying to hang in the race.

Before the season started, I wrote the Positional Power Rankings entry for catchers. The Red Sox slotted in at 19th, neither particularly good nor particularly bad. I thought the bulk of the playing time would go to Blake Swihart. The rest of the time would be more or less split between Ryan Hanigan and Christian Vazquez. Swihart was the up-and-comer with the bat. Vazquez was the defensive specialist. Hanigan was the reliable vet. Those were the three names; Leon’s name was nowhere to be found.

Swihart is done for the season, and before he was done for the season, he was playing left field. The Red Sox weren’t jazzed about his defensive work behind the plate. Vazquez is always defensively steady, but he’s run a 51 wRC+. Hanigan, meanwhile, has run a seemingly impossible 11 wRC+. Hanigan has been horrible. Swihart has been unavailable. Vazquez has been unimpressive. Enter Leon, who’s turned into the regular. The regular with the highest wOBA out of anybody with at least 100 trips to the plate. Leon himself wouldn’t have dreamed this could happen.

I came across a funny quote. From early July:

“Everybody knew he could swing the bat, but what he’s doing…” reliever Matt Barnes said, trailing off and throwing up his arms with a grin. “I don’t think anybody could have predicted this — even him.”

Relative to the world’s population, of course, Leon is a fantastic hitter. Relative to the major-league population, not so much. I’m not actually convinced that everybody knew he could swing the bat. In the majors between 2012 – 2015, Leon managed a 32 wRC+, with one homer. Last year alone, in the majors, only Pete Kozma swung a less-productive bat. In the minors, Leon has posted a career .654 OPS. In the minors just this season, Leon posted a .655 OPS. There’s just hardly any track record.

We can’t even try to point to something mechanical that Leon has tweaked:

“Probably confidence,” said Farrell of the difference in Leon this season. “I can’t say that the swing has changed all that much. He’s not missed pitches when they’ve been on the plate.”

I’m writing this in the middle of a Red Sox/Yankees game Thursday evening, and apparently Leon is already 2-for-2 with a bloop double. Not counting the game in action, Leon has 128 plate appearances this year, exactly equal with his total from last year. Last year, he was bad. This year, he’s been amazing. Of course, there’s dramatic BABIP inflation, but the huge difference is power. Last year, Leon hit two doubles. This year, he has 10 doubles, two triples, and four homers. All in the same number of chances. I don’t have a prayer of understanding, but, here we are. Last summer I wrote about how a Ryan Goins hot streak confused the hell out of me. This might’ve been even more unexpected. Leon was mediocre in the minors earlier this very year.

I want to show you a table that really gets to the heart of this. I looked at everyone with at least 100 plate appearances, then I compared actual wOBA to preseason projected wOBA, according to ZiPS. The top 10 overachievers:

Leon has since increased his wOBA another 10 points. Very, very clearly, this is partially driven by the small sample size of his season, but if you look at the other end of this same list, the very top underachiever is Hanigan, off his projected wOBA by 95 points. There’s maybe some luck balancing out. Leon’s surge has come at a crucial juncture.

Even when he was bad, Leon could make contact. He’s a switch-hitter with a pretty compact swing. That contact ability hasn’t gone away, but there’s more here of actual intrigue. Statcast knows of 341 hitters with at least 50 recorded batted balls in each of the last two seasons. Leon’s average exit velocity shows the fifth-biggest improvement in the sample. His average launch angle shows the 11th-biggest increase in the sample. There’s almost enough there for you to buy that Leon has figured something out, but then you stumble over his numbers in Triple-A. I can’t provide for you the big answer. I can just say, hey, what a great time for Leon to look like he can actually do something. The Red Sox have needed it. Leon’s career probably needed it.

He’s also pretty good at defense, by the way. So pitchers and coaches trust him. It’s how Leon racked up big-league experience even when he wasn’t hitting. He’s an acceptable receiver, and he’s got a strong and accurate arm. He seems to be able to manage a staff. If it weren’t for the whole history, you’d look at Leon today and think, that guy, that guy right there, he’s a keeper. He’s only 27 years old.

And I have no idea how much he’s actually figured out. It stands to reason he’s figured out something, but he’s not as good a hitter as David Ortiz. As for how much worse he really is, I can’t yet say. What can’t be denied is that one of the least productive hitters in major-league baseball has become one of the most productive hitters in major-league baseball. The stats are all facts. Leon will slow down and he’ll resemble something easier for us to understand, but now he’s on the map, having saved the Red Sox catchers’ season. Sometimes things don’t at all go according to plan. Sometimes you can be happy throwing the plans away.