If the Cubs are going to make some moves towards their first full-season division title since 2017, it’s not just going to be about new additions like Kyle Tucker, Ryan Pressly, Justin Turner and Matthew Boyd.

It’s going to be about improvements from returning players, too. It’s going to be about whether rookie infielder Matt Shaw can contribute, and whether catcher Miguel Amaya’s late-season hitting adjustments were for real, and perhaps most of all: Which version of center fielder Pete Crow-Armstrong will we see in 2025?

Crow-Armstrong isn't the flashiest name on this roster -- yet there might not be a more important player for the success of this year’s team.

If it’s the version that hit only .186/.246/.302 in his first 73 career games – through the 2024 All-Star break – then no amount of speed and defense is going to save you, even if we’re talking about the player who was, in fact, the best speed-and-defense player in the game last season. (Not just good: The Best, combining largest-in-baseball leads with elite speed and fantastic fielding.)

Yet if it’s the version that hit .262/.310/.425 in 63 games after that (a boost of 188 points of OPS), then maybe the Cubs really have something here. When you can run and field like that, you don’t have to hit all that much to succeed. When you can do both, you have something like one of the top 40 or so players in the game, which he was by Wins Above Replacement (WAR) in the second half.

But you do have to hit a little, and never more urgently than this year, when the Cubs have fully entrusted Crow-Armstrong with the center field job without much of a safety net behind him. Last season, he was one of three Cubs to make a start in center field. The other two – Cody Bellinger (47 starts), and Mike Tauchman (six) – are no longer on the roster. If Crow-Armstrong can’t make the job his own, then the Cubs will have to turn either to utility players or as-yet-unproven 22-year-old prospect Kevin Alcántara, who has all of one career Major League hit.

It is, of course, quite nice that Crow-Armstrong is having a massive spring, hitting .519/.500/1.000 in Cactus League play before the Cubs headed to Japan to open the season against the Dodgers in the Tokyo Series next Tuesday and Wednesday.

It also doesn’t matter that much, really. “Spring is meaningless,” Cubs president of baseball operations Jed Hoyer told the Athletic last week. “I assume whoever looks good will have a .520 OPS in April.” He wasn’t speaking specifically about Crow-Armstrong – or, for that matter, Tucker, who's having a miserable time in Arizona – but you get the idea. It’s nice to see. It’s not terribly predictive.

What, then, changed last summer? Simply a young player getting comfortable? Hard to quantify, but easily believable. The leg kick he added? Perhaps. A minor change in bat size? He believes so. A change in swing plane? No, says the data. But there’s more to it, too. Thanks to new Statcast data coming soon to Baseball Savant, we can see that he moved way back in the box as the season went on – a full foot back, actually.

You can see the move here, comparing June vs. August. Crow-Armstrong is 13 inches farther back, and 4 inches closer to the plate. Look at how much farther back his feet are. In June, he was deeper than just 6% of other hitters. By September, he was deeper than 95% of hitters.

That clearly couldn’t have happened by accident – and it didn’t. When asked about it this spring, he noted it was a deliberate decision.

"I'm definitely trying to give myself a chance to be able to see the baseball for as long as possible,” Crow-Armstrong said. He later added that, “I don't really know if I've found my most comfy spot in the box yet, but I think there's definitely something to being able to see the ball for as long as you possibly can, giving yourself time."

That’s a reasonable, analytical way to think about it. But there’s more to it, too. It’s about what feels right, a good reminder that we’re watching people, not robots.

“If I'm being honest, the dumbest way to explain it is, in the seventh inning of the game there's a [expletive] massive hole in the back of the box. That's where most guys stand. So it was either, like, I can scoot way too far up in the box and not worry about the hole, or I can just step where everybody else is stepping."

It’s very noticeable. But: Does it matter? It’s not as clear as “move back and succeed,” or else everyone would be doing that, and the batter who is the farthest up in the box, Jose Altuve, is on a Hall of Fame path. These things are rarely one-size-fits-all.

In Crow-Armstrong’s case, he already told us what he thinks it did – “give myself a chance to be able to see the baseball for as long as possible” – and one way that manifests itself is to see if he chased breaking stuff less. We can easily see when he first took that step back, because the first day he was at least 30 inches deep in the box was on July 29, a line he stayed beyond essentially for the rest of the year. That’s a convenient date for us, narratively, since Cubs hitting coach Dustin Kelly said last summer that a turning point in Crow-Armstrong’s season was a drill they did while on the road in Kansas City, and wouldn’t you know it: the Cubs were there from July 26-28.

If you were going to put some stock into "being able to see the ball longer," you might expect to see an improved chase rate on breaking balls, an issue that has long vexed Crow-Armstrong. For the sake of ease, we’ll just split it into “first four months” vs. “last two months,” and, well, wouldn’t you know it: yes.

Crow-Armstrong's chase rate on breaking balls

• April-July: 57%
• Aug.-Sept.: 45%

To be clear, 45% isn’t exactly good; the Major League average is 31%. But we’re not trying to turn PCA into Juan Soto, either. We’re trying to see if the bat can be competent enough to allow the speed and defense to shine. Any improvement is welcome.

It is, however, not just about the chase. It’s about where his contact is being made. For most players, hitting the ball in the air is a good thing, and pulling that ball when it’s in the air is an even better thing. “Most players,” however, is not “all players,” because surely you’d never expect – or desire – Giancarlo Stanton and Luis Arraez to have the same hitting approach.

In Crow-Armstrong’s case, we have the type of chart that is almost never this clear. When he tried to pull the ball, he was bad. When he stopped trying to pull the ball, he was far more productive.

Go back to the first image we showed, but worry less about the feet, and more about the dots in the middle – the intercept point, where the bat is meeting the ball. It was, for a while, 13 inches in front of the plate. By August, it was two inches behind the front of the plate, a massive change. The angle of his bat didn’t really change. His stance didn’t get more open, or closed. But because he wasn’t so far up in the box, he wasn’t trying to get that contact out in front, either. "Seeing the ball longer" might also just be about "where you impact the ball," beyond swing decisions.

The move back, as he said, was both strategic (see the ball longer) and practical (that’s where everyone had left the hole in the dirt).

"Yeah," Crow-Armstrong laughed when asked. "[It’s] what you're left with as the seven-hitter in the lineup."

The bottom third is, once again, where Crow-Armstrong is likely to start the season, with either Ian Happ or (when healthy) Nico Hoerner likely to lead off. But if last season’s changes stick, it might be too difficult for manager Craig Counsell to resist the urge to put this kind of speed atop the lineup eventually. If he does, Crow-Armstrong might find himself in a particularly unusual situation, especially in road games: Standing in a pristine batter’s box, with no [expletive] massive hole to worry about.

If those changes stick, the Cubs, too, might find themselves in a recently unusual situation as well: the playoffs.

MLB.com’s Jordan Bastian contributed to the reporting of this article.