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Back on June 23, I wrote an article called “What’s Going on With Wan Steven Kwan?” A week later, Kwan responded, “Nothing!” Well, he said it with his bat, anyway. On July 1, he went 1-for-2 with a triple, then 1-for-2 with two walks the next day, and then he hit another triple two days after that. Since July 1, Kwan is batting .350 with more walks than strikeouts for a 154 wRC+. My deep dive into Kwan’s troubles was an attempt to answer a question from a reader named Kevin, and now that Kwan is back on top again, Kevin has written back to ask what’s changed. I wanted to write about it, but this graph gave me pause.

Kwan got unbelievably hot at the beginning of July, and then he spent the next two months and change slowly cooling off. Every batter’s rolling wRC+ graph is full of ups and downs, but this one made me a bit wary. Zack Meisel had written a story about the turnaround for The Athletic back on September 1. In it, Kwan described poring over journal entries from previous slumps looking for the right attitude adjustment to get him back on track. And then over the next 12 games, Kwan ran a wRC+ of 80 and struck out twice as often as he walked. That’s the danger of writing about a hot streak. But over Kwan’s most recent 10 games, he’s back on top with a 178 wRC+, and honestly, I’m still curious. Has he fixed whatever was wrong? Is this just about BABIP? I really don’t know, Kevin. I’m writing this introduction before I dig into the numbers so that we can go on a journey of discovery together. Let’s away.

Back in June, what stood out to me was that Kwan had taken his already extreme offensive profile and pushed it to limits we’ve never seen before. As I wrote then:

Among qualified players, his current 97.8% contact rate on pitches in the strike zone is the highest ever recorded in the Statcast era. His squared-up rate is the fourth highest since Statcast started measuring it in 2023. And while his chase rate isn’t the lowest of his career, Statcast doesn’t give us percentiles for swing rates specifically on pitches in the zone. His is the fifth lowest recorded in the Statcast era, and it’s more than four percentage points below his previous low. He’s running the second-lowest bat speed ever recorded. He’s also running the second-lowest hard-hit rate ever recorded, above only 2018 Billy Hamilton.
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Kwan has always built his game on patience and contact ability rather than aggression and power, but this year he’s out-Kwanned himself, and the results have been dreadful. He’s running a 67 wRC+, tied for fourth-worst mark among qualified batters.

I also noted that Kwan was running a .229 BABIP and underperforming his xwOBA by 31 points. He’d gotten pretty extreme, but it also seemed like there might just be some bad batted-ball luck going on. Here’s the same graph I showed you earlier, but it’s got BABIP in there too, and, well, those two lines sure do seem to move in tandem.

I know Kwan’s walk and strikeout rates have fluctuated, but it looks at a glance like batted-ball luck can explain a whole lot of both his struggles and his turnaround. Regardless, let’s start by updating all those numbers I mentioned back in June.

So most of these numbers have gotten a bit less extreme, which is exactly what you’d expect extreme numbers to do. The two changes that stick out the most are in the bat speed and line drive rate columns. We’ll get to line drive rate in a bit, but a change of 0.7 mph in bat speed is a significant shift, especially because it’s not bouncing back, like all the other numbers. Somehow, Kwan has dropped his bat speed even further. He had a fast-swing rate of 0.5% at the time, and he hasn’t been credited with a single one since. For the season, his bat speed is now at 62.4 mph, which is no longer the second-lowest mark ever recorded. It’s the lowest outright. It’s fallen against all three kinds of pitches.

And it’s dropped even further due to the proportions. Kwan started swinging at fewer fastballs and more slow stuff, and fastballs tend to induce slower swing speeds. Moreover, when he does swing at fastballs, his approach is very different. Over at Baseball Prospectus, Matthew Trueblood broke that down further, just a week after Meisel’s article. Matt, I should hasten to add, is one of the game’s great noticers. I don’t know how he does it, but he always seems to find crucial details that I never would’ve thought to look for in the first place, and this is a great example.

Matt noted that before July, Kwan was trying to do damage on fastballs by pulling them in the air, but instead he was rolling over them for groundouts over and over again. Before my article, Kwan had a 28% pull rate against fastballs. Since then, that number is 21%. His pull rate against breaking and offspeed pitches stayed nearly identical. So before, Kwan was trying to get out in front of the fastball; now he’s waiting back on it, and often deciding to let it go entirely. As you might guess knowing that his pull rate is down, Kwan is specifically laying off the inside fastball.

I’m sure you know about the contours of Kwan’s game, but it’s worth restating it at this point. He’s got elite plate discipline and contact skills, which allows him to run great walk and strikeout rates. He waits back and sprays singles from foul pole to foul pole. What slugging he’s able to muster comes in two forms. First, some of the line drives get sprayed right down the left field line for doubles. Second, Kwan will, just often enough, turn on the inside pitch, ripping it into the gap or down the line for a double or a homer. Well, since his turnaround, he’s not turning on those fastballs, so his pull rate has dropped, as has his launch angle. Before my article, he had a launch angle of 15 degrees and his batted balls averaged a distance of 165 feet. After it, those numbers were 9 degrees and 149 feet. That’s a huge difference, and it brings us back to the line drive rate.

Kwan didn’t drop his launch angle by putting the ball on the ground more. His groundball rate is virtually unchanged. He just somehow turned a ton of his fly balls into line drives. Kwan put up a preposterous 45% line drive rate in July. If you set a minimum of just 50 batted balls (and Kwan had 71), that’s the ninth-highest calendar-month line drive rate in the entire Statcast era. No wonder his BABIP shot through the roof!

Kwan’s whole game revolves around line drives, so I don’t think we can pretend that this hot streak is just noise. Line drive rate isn’t the stickiest stat in the world (and as proof, I can tell you that in that single-month leaderboard I mentioned earlier, only one person, Ben Gamel, appears in the top 30 more than once), but that doesn’t mean it carries no signal. This is what Kwan looks like when everything is going right. He’s walking, avoiding strikeouts, and racking up tons of line drives. That said, he’s still seeing his batted-ball luck bounce back in some interesting ways. For example, those two triples I mentioned in the first paragraph, the ones from back in July? Both were misplays that normally would’ve gone down as singles or doubles.

During the rough stretch, Kwan’s batted-ball makeup got weird in a different way. It wasn’t just that he made more contact, but also that more of his contact turned into balls in play. In 2025, he fouled off the ball on 42% of his swings. Since June 23, he’s again at 42%. But while he was struggling so mightily, his foul rate dropped to 36%. That’s not normally how things go; players who make tons of contact tend to foul the ball of a lot, so seeing Kwan’s foul rate drop while his contact rate increased is a little odd. I know that because a couple years ago, I did a whole investigation into foul balls, and I found that it’s best to think about them as almost-whiffs. In the same way that when you chase a terrible pitch, you’d rather miss it entirely, because one strike is not as bad as a weakly hit ball that turns into an out, you’d also rather have your bad contact go foul. It’s so weakly hit that it’d be an automatic out if it were fair.

Maybe I’m off base here – maybe the fouls were just another example of Kwan’s ability to make even more contact – but this seems like the kind of randomness that could contribute to some ugly batted-ball luck. Remember, his contact rate went up at this point, so those former fouls weren’t turning into whiffs; they were turning into balls in play, and that works out to nearly one per game. Adding one weakly hit ball per game is enough to sink anybody’s batting line.

All of this is to say that, as usual, I think there’s a mix of noise and signal in these hot and cold streaks. Kwan has definitely earned a lot of that higher BABIP. He’s changed both his attitude and approach, and he’s hitting line drives like crazy. You can’t do that if you’re not locked in. But he can’t control how many of them fall in for hits. And my diagnosis from June, that Kwan had out-Kwanned himself by slowing his bat speed even further than usual wasn’t quite right, because Kwan discovered another, even lower gear en route to righting himself. The good news is that with the playoffs starting on Tuesday, he’s exactly where he wants to be.