From now on, maybe we should ignore the numbers until Juan Soto is leading the league in walks. Soto has had the highest walk rate in baseball in each of the last four seasons. And he’s close this season! He’s got 21 walks (tied for first) and a 17.4% walk rate (tied for third). But first place belongs to Riley Greene, and that’s a surprise. Greene is not the person you’d expect to top this list. Excepting a two-game stint in Single-A in 2022, he hasn’t run a walk rate above 12% at any stop of his career, but this season, he’s at 19.6%. Since 1903, the largest single-season jump in walk rate by a qualified player in AL/NL history was 10.7 percentage points, by Barry Bonds in 2004. Right now, Greene is sitting on a jump of 11.2 percentage points. He’s also sitting on a 157 wRC+, thanks to a .244 ISO that ranks 22nd in baseball, just behind Soto. Aside from the fact that it’s still April, what exactly is going on?

For the second year in a row, Greene has cut his chase rate, and this year the drop is more than five percentage points. Want to walk more? Not swinging at balls is a great start! But take a look at his swing rate on pitches inside the zone.

It’s down by nearly 10 points! Among all qualified players, Greene has the 12th-lowest overall swing rate, by virtue of being 27th lowest outside the zone and 24th lowest inside it. It’s not just that he’s chasing less, it’s that he’s being much less aggressive overall. With such a big drop on pitches inside the zone, I wondered whether Greene had become too passive. After all, his exit velocity numbers are down a bit, and his 63.2% swing rate on meatballs (pitches right down the middle that you should definitely be swinging at) is 15th lowest among qualified players. However, according to Robert Orr’s SEAGER metric, not only is Greene making better swing decisions than he did in 2023, he ranks 17th in all of baseball (minimum 70 plate appearances). Greene has cut his swing rate in the heart zone by 15 percentage points, but apparently cutting nine percentage points off his swing rate in the chase zone was a worthy tradeoff.

Despite being so much choosier, Greene has improved his contact rate by less than a percentage point, which is somewhat odd. We can see what’s happening when we break things down by pitch type. He has cut his in-zone swing rate by roughly the same amount against all three categories of pitches, but look at the breakdown of his chase rates.

Offspeed pitches are still his biggest problem, but he’s halved his chase rate against fastballs, and cut his chase rate against breaking pitches by a quarter. No one who has seen at least 100 fastballs outside the zone has chased fewer of them than Greene. This helps explain things: He’s making a hair more contact on pitches inside the zone, but his contact rate on pitches outside the zone has fallen by nearly five percentage points. That’s what happens when the pitches you’re chasing are harder to hit. In 2023, fastballs (which run lower whiff rates) made up 37.6% of the pitches Greene chased. So far this year, they’re just 19.2%.

It’s important to keep in mind that a player’s contact rate on pitches outside the zone isn’t necessarily that important. Chasing and whiffing isn’t great, but chasing and making weak contact is usually worse. That’s part of the reason Greene is getting into deeper counts and working so many walks. Even though he’s swinging at way fewer strikes, more of the balls that Greene actually puts into play are coming on pitches in the zone: 83.1%, up from 80.7% in 2023.

Before we end, I would like to take you on a brief detour. I mentioned before that Greene’s in-zone swing rate has dropped more or less indiscriminately. He’s down roughly eight points against offspeed pitches and 10 points against fastballs and breaking balls.

Understandably, opponents have reacted to this by throwing Greene a lot more offspeed pitches. In a somewhat odd side note, Greene is under the impression that he has, in fact, stopped chasing changeups. “Heater in, changeup away,” he told reporters. “It’s almost automatic now. Until I can prove that I can lay off the changeup away, they’re going to keep throwing it. And I feel like I’ve been doing a good job recently of laying off the changeup away.” To be clear, he is swinging at significantly fewer changeups, but only inside the zone (where he’s swinging at less of everything). That is in itself a victory, as offspeed pitches give Greene a ton of trouble, but he’s still chasing them at a nearly identical rate. In 2023, 14.6% of his swings came against offspeed pitches. In 2023, that number is 28.6%. It’s nearly double! His 2023 swing rate is on the left, and 2024 is on the right.

Greene has done a great job of laying off elevated fastballs this season, and he’s also done a better job of laying off low breaking balls. But because so many of his swings are coming against changeups, his swing zone is focused down and away. When he swings at offspeed pitches, he’s worse than ever. He’s running a .158 wOBA and a 50% whiff rate against them, and his 83.5 mph exit velocity against them is dragging his overall EV numbers down. However, because he’s picking better fastballs and breaking balls to swing at, he’s barreling up nearly twice as many balls as he did in 2023.

These are all knock-on effects of the big news. The big news is simple: Riley Greene has slashed his chase rate against breaking pitches and decided to stop chasing fastballs entirely. That’s why he’s walking more, and that’s huge. Even if he never figures out how to stop chasing changeups, this is an improvement. However, we’ve still got a few more days left in April, so I am legally obligated to end by throwing some cold water on everything I just told you. Take a look at the 15-game rolling average of Greene’s walk and chase rates.

In both 2022 and 2023, Greene started out passive, and then got more aggressive over the next couple weeks. Presumably he’ll start swinging more at some point, and presumably Soto will ease back into pole position. But even if Greene’s aggression goes all the way back to his career norms, it’s definitely encouraging that he’s displaying better pitch recognition and a better understanding of the strike zone. It wouldn’t be the worst thing in the world for Greene to get some of his old aggression back, especially if he can keep any of the gains he’s displayed in the past month.