It’s not a news flash that Juan Soto was great in 2018. The simplest of statistics could tell that story. His OBP started with a 4. His slugging percentage started with a 5. He had 22 homers in a mere 116 games. However, the real hype starts when you dig into the numbers a little more. Juan Soto was 19, and he walked 16% of the time in the big leagues while putting up a 146 wRC+. People are making historical comparisons because that’s the only way to appreciate such a tremendous feat. No one in history has put up a better batting line before their 20th birthday, and the only people to come close are Mel Ott, Tony Conigliaro, and Ty Cobb. When you put it that way, maybe we’re underselling how great Soto’s 2018 was.

I’m not writing today to remind you of how good Soto’s 2018 was (like, really good though! Really good!). Instead, let’s talk about the approach he used to generate those numbers. Here’s a leaderboard of the 10 best hitters in baseball by wOBA last year, minimum of 450 PA. I’m using wOBA instead of wRC+ for compatibility with data further along in the article:

Well, that’s about what you’d expect. Ten great hitters, or potentially nine great hitters and Max Muncy, depending on how you feel about him. Paul Goldschmidt was eleventh if you want to leave Muncy out of this. That alone is already amazing. What makes it really impressive, however, is that Soto did it all against fastballs. I’m going to throw another leaderboard at you.

Here are the top 10 hitters in baseball in 2018 on plate appearances that ended in fastballs (200 PA minimum):

There you go. Soto was the best hitter against fastballs in the majors last year, slugging an outrageous .696 against them. Just to make it super clear that I’m not cherry-picking some tiny split here, Soto had 282 plate appearances end in a fastball. His xwOBA against them was a robust .462. Era comparisons are always tricky, but just as an approximation in your head, if you threw a fastball to Juan Soto in 2018, he hit like Ted Williams’ career line. Again, as a nineteen-year-old!

I’ve left something out in these numbers: performance against, you know, the rest of the pitches in baseball. You can probably surmise from how good Soto was against fastballs that he didn’t dominate to the same extent against off-speed and breaking pitches. If he had, he’d be the best hitter in baseball rather than the seventh-best. It’s reasonable to expect a drop-off between the two categories anyway. The league as a whole recorded a .344 wOBA on plate appearances ending with fastballs and a .271 wOBA against everything else. Hitting stuff that moves is hard! The best thing you can do is often just not swing at it. Here’s one last leaderboard — the top 10 hitters against non-fastballs, minimum of 150 PA:

That’s an impressive list of hitters again, but this time no Soto. What, is he 12th or something? Twentieth? He’s (pause for counting)… 163rd. He’s 163rd out of 227 hitters, no less, with a wOBA of .259. Among the 10 best overall hitters in baseball last year, the second-worst against off-speed pitches was Jose Ramirez, and he recorded a .311 wOBA there. Soto is an outlier both ways — preternaturally good against fastballs, but undeniably mediocre in 2018 in plate appearances that ended any other way.

It’s really impressive to think that Soto is already such a great hitter while still having room for improvement. To me, at least, that’s what his performance against breaking balls suggests. There simply aren’t baseball players capable of hitting as well as he does against fastballs who can’t figure out a little bit of a wiggle on the ball’s flight path. Even in 2018, however, Soto had an adjustment ready. See, when you think of Juan Soto, you think of plate discipline and patience, and you’re not wrong. Of hitters to record at least 450 PA last year, he had the 11th-lowest swing rate. The man (recent boy? It’s still wild that he just turned 20) simply doesn’t swing much.

Swing rate, however, masks something about Soto’s profile. When he sees breaking balls, the bat just stays on his shoulder. He has the third-lowest swing rate against non-fastballs, behind only Ramirez and Alex Bregman. His selectivity isn’t leading to better contact when he swings, or anything like that — he still whiffs on about a third of those swings, and it’s not like he’s doing a lot of damage when he connects. It seems, rather, like he has just done the math in his head. Why swing at these pitches when pitchers will eventually throw fastballs? When they do throw fastballs, he ups his swing rate considerably, going from 34.5% (junk) to 42.5% (heat).

“Just swing less at hard-to-hit pitches” is obviously easier advice to give than to put into action. It’s not as easy as just saying you’re not going to swing at splitters and sliders — the whole point of those pitches is that they’re hard to distinguish from fastballs coming out of the pitcher’s hand. In fact, league-wide swing rates for the two types of pitches are about the same, just below 47%. Some of that is due to breaking balls being thrown more often in counts where hitters need to swing — two-strike counts, or more generally whenever the pitcher is ahead. Still, that bias is present in Soto’s swings as well. He’s just a savant when it comes to recognizing pitches out of the hand (this word choice brought to you by Baseball Savant, whose search function I used to generate basically all of this data).

If you’re a pitcher, this doesn’t leave you with a lot of great plans against Soto. You can’t throw him fastballs, that much is clear. You want to pitch to Ted Williams? I thought not. Okay then, try to get him out with soft stuff. The problem is, he’s probably not going to swing at it. On soft pitches outside of the strike zone last year, Soto swung 18% of the time. That’s… not very many swings. League average is about 31.5%. For a little further orientation, Mike Trout swings at about 25% of these pitches, and inhuman all-seeing strike-zone god Joey Votto swings at 12%. Throw Soto a ball and you’re probably wasting a pitch.

Okay, fine, no fastballs and no secondary pitches outside the strike zone. I can do the math — let’s just throw him junk in the strike zone. What could go wrong? Well, first of all, that’s not a pitch that every pitcher has. Sonny Gray eloquently said as much this offseason in an interview with Eno Sarris: “When I try to throw sliders for a strike, I get around it and it’s just a s—-y spinning pitch. I don’t know how people throw sliders for strikes that are still tight, good pitches. I’m at 2–0 and I’m throwing a slider, and either I’m throwing a s—-y slider in the zone, or I’m yanking it into the dirt and it’s 3-0 and I’m screwed either way.”

That’s one reason you don’t see pitchers throwing Soto a steady diet of sliders in the zone. Another reason is that it’s not always a great idea to throw slow pitches in the strike zone. Batters might swing at them! That’s an obvious disadvantage of throwing in the strike zone, but it bears mentioning. Batters swung at 67% of breaking and off-speed pitches thrown in the strike zone last year, and that’s a lot of swings at pitches that don’t move particularly quickly. To be a bit more descriptive, at-bats that ended with the combination of a non-fastball in the zone and the hitter swinging produced a league-wide wOBA of .328. That’s not devastating or anything, but it’s about league-average for all plate appearances, and that’s generally not what pitchers are looking for from their secondary pitches.

In Soto’s case, however, there really might be something to the plan of throwing secondary pitches in the strike zone. As we discussed above, he’s not going to swing at a ball. If you throw him a fastball, he’s the best hitter in baseball. Off-speed pitches in the strike zone, however, gave him fits. First of all, he only swung at 54% of them. That’s quite low — tied for the lowest in baseball, in fact, which means that you’re getting a free strike about half the time. When he does swing, he doesn’t do much damage — Soto compiled a .226 wOBA, worse than Chris Davis’s season-long line last year, on at-bats ending in those swings. Well, looks like we solved it! Want to get Juan Soto out? Throw your secondary (or tertiary) pitch for a strike, and don’t over-spin it. It’s your only shot — otherwise he’s taking a walk or taking some cuts at your fastball, and you don’t want that.

Oh yeah, one more thing. I’ve used the present tense in this article, but these are 2018 stats, and again, Juan Soto was a teenager. He’s still learning, and he’s had a whole offseason to do it. Rest assured that Soto knows this is something he needs to work on. The Nationals’ hitting coach, Kevin Long, said as much when he described a phone call with Soto during the MLB Japan All-Star series this offseason: “So I’m watching, and I see a game in Japan, ‘Oh, Juan Soto, there’s a breaking ball, BANG!’ And then first thing he says, he goes, ‘Did you see that curveball I hit?’” Safe to say, Soto knows he needs to work on hitting breaking balls, and that’s a scary thought. Juan Soto, holes in his game and all, was a top 10 hitter in all of baseball last year as a 19-year-old. If he fixes his issues with breaking balls, the sky is the limit.