Three seasons ago, the Chicago Cubs won 73 games. In 2015, that number jumped up to 97. And last year, well, you know what happened. In consecutive campaigns, Joe Maddon and Co. made the proverbial leap: from a mediocre team with potential to a bona fide mid-tier contender to a flexible juggernaut that looks set to dominate the sport for years to come. So this week, as part of The Ringer’s 2017 MLB Preview, we’ll be taking a look at what other teams and players — good, bad, and otherwise — are poised for some sudden improvement this season. It’s Make the Leap Week!

Here’s a secret about baseball previews: Breakout-player picks are all little lies. If any writer or pundit could reliably identify players who were about to go from obscure to All-Star, that writer or pundit would probably be building an actual baseball team or winning fantasy leagues at a Meat Loaf–like rate. Calling big breakouts before they take place is something we all quickly discover we can’t accomplish with any kind of consistency, BBWAA badge or no. So instead of a crib sheet listing the coming season’s secret superstars, what we tend to get is a mix of players who’ve either already broken out or who’ve been about to break out for so long that no one would be shocked to see it happen.

Byron Buxton probably belongs in both categories, which makes him a breakout king this spring. Click on Jon Heyman’s list of breakout candidates for each team, and there, among little-known names such as José Bautista, Noah Syndergaard, Corey Seager, and Gary Sánchez, you’ll find Buxton next to “Twins.” He’s one of three players with a photo on the page, and his blurb includes the adjectives “off the charts” and “untouchable.”

Buxton has to be there, because he was, until recently, a top prospect — no, not a top prospect, the top prospect. Baseball America, Baseball Prospectus, and MLB.com all ranked him no. 1 in 2014 and kept him in their top two in each of the next two springs. The raves matched the rankings: In 2014, then-Baseball Prospectus prospect writer (and current Cubs special assistant to the president and GM) Jason Parks reported that a non-Twins executive had told him Buxton had a Torii Hunter floor and a Willie Mays ceiling. The tool grades started at 60 (for power) on the 20–80 scouting scale and climbed higher from there. And last September, following his fourth promotion to the majors, Buxton appeared to deliver on the hype, batting .287/.357/.653 with nine home runs to go with his usual top-of-the-scale speed and defense in center, and tying for the major league lead in WAR.

I was tempted to write “deliver at last,” but Buxton’s growing pains only felt long-lasting, thanks to the stark contrast between our early expectations and his initial results. Through August of last year, Buxton was a minor league stud but a lifetime .199/.248/.319 hitter in the big leagues, with 124 strikeouts and 19 walks in 356 plate appearances — the kind of poor plate discipline that kills careers. Only two hitters, Chris Carter and Mark Reynolds, have struck out that frequently while playing enough to qualify for a batting title, and both had power well beyond Buxton’s. No credible sources were seriously using the “bust” word, except to say that Buxton wasn’t one yet, but there was cause for concern; as Eno Sarris noted last June, no prospect other than Javier Báez ranked in the top 10 by Baseball America had ever done so much whiffing with so little walking in his first 200 plate appearances.

If the talk about ceilings subsided for a time, Buxton’s last month brought it back. “His ceiling is as high as it can be,” former major leaguer Chad Allen, who’s been Buxton’s hitting coach in Double-A and Triple-A, says via phone. “He’s got potential to be a top-10 player in Major League Baseball.” The difference now is that Buxton has actually played at that level, albeit briefly.

He’s also lost his rookie eligibility, which means that this is the first spring since he was selected second overall in the 2012 draft in which he hasn’t appeared on prospect rankings. Buxton never minded people pumping him up: “It was definitely a ray of sunshine, you can say, when you see your name in that prospect list,” he says via phone. But he won’t miss the resulting deflation when he fell short of the instant success often forecasted for him. “I’m definitely glad that that has passed over me, and now I can just focus on not having to worry about ‘Oh, he’s this position, so he should do that.’”

In reality, the pressure remains, and not only because “no. 1 prospect” is either a stain or a status symbol that sticks to players forever. Only the rubric has changed: Now he’s just being judged by what he’s producing in the present. Buxton turned 23 in December, but because he debuted in an era of unprecedented plenty for young talent, he’s already behind the precocious curve his contemporaries have set. Many of the players who ranked below him on those 2014 prospect rankings — Xander Bogaerts; Carlos Correa; Kris Bryant; Francisco Lindor; Syndergaard; Seager — are already on the short list of the best players in baseball.

Related Corey Seager Is on Pace to Have a Better Career Than Alex Rodriguez

Buxton, who’s batting .266/.333/.526 with a modest 16.3 percent strikeout rate this spring, says his offseason goal was to “take my September over into spring training and keep things going.” So what can we learn from his one torrid major league month?

Buxton didn’t embrace the uppercut swing style that’s become all the rage recently; in fact, his average big league launch angle fell from 17.1 degrees in April through August (31st among 341 hitters with 100 tracked balls) to 9.0 degrees after August (137th among 181 hitters with at least 50 tracked balls). This is, after all, a hitter who as recently as last June said his goal in the batter’s box was just to “try to hit a hard ground ball to second base.”

“That’s the amazing thing about him,” Allen says. “Bux is not a guy who you look up and he’s 6-foot-[2] and weighs [215] pounds like an Adam Jones. Bux is 6-foot-[2], weighs [190] pounds, but he’s got phenomenal hand speed, which gives him … the ability not to have to try to elevate a baseball to get it out of the yard.”

Late last year, however, Buxton did start pulling the ball at a rate that rivaled league-leading teammate Brian Dozier’s.

“It’s more of me being on attack mode and not being passive,” Buxton says about his rising pull rate. “That mindset that I had in September is the mindset that I have now. You can’t go up there and try to hit all the time on 0–2.”

Attacking translated to harder-hit balls, as Buxton’s average exit speed increased from 89.3 mph at the end of August to 91.9 thereafter, topping out at 111.3 in the “after” period, up from a high of 109.8 in the “before.”

We can come up with caveats, even without invoking the weakened pitching of the post-roster-expansion period. Although Buxton was raking, he was still striking out 33.6 percent of the time, sixth most among qualified hitters over that span. His September/October “Three True Outcomes” rate, 50.4 percent, has been matched by only 12 qualified hitters in history, all of them corner/DH types in the mold of Adam Dunn, Rob Deer, and Jack Cust. It’s an odd offensive profile for someone so fast and athletic.

Buxton says he can succeed without making much more contact. “Strikeouts are in the game, so I’m not going to worry myself about striking out,” he says. “I mean, everybody strikes out in this game.”

As of this spring, Major League Baseball Advanced Media can calculate estimated batting stats derived from Statcast launch-angle and exit-speed data. The table below displays Buxton’s expected weighted on-base average, or wOBA, based on his strikeout and walk rates and the locations and velocities of his batted balls.

The good news is that Statcast supports the idea that Buxton got better, showing an improvement of more than 100 points after his most recent call-up. The bad news is that his estimated wOBA was still more than 100 points lower than the real-life figure, and pedestrian relative to the league. (For reference, the average wOBA for an AL non-pitcher last season was .321.)

The caveat to the caveat is that this method is based on typical batted-ball outcomes, which means it assumes average speed. Buxton’s speed is as far from average as it’s possible to be. Statcast also tells us that he’s the fastest right-handed hitter in baseball, owner of the fastest righty home-to-first time on a non-bunt as well as the four fastest home-to-third times, nine fastest home-to-second times, and a record 14.05-second home-to-home time on an inside-the-park homer.

“Low velocity and low angle will equal a low hit probability, even if his speed allows him to beat some [poorly hit grounders] out,” says MLB.com analyst Mike Petriello. “I also see some singles that he ran into doubles.”

In other words, Buxton’s speed will always allow him to exceed an estimate calibrated to the typical player. A figure that factored in his speed would be closer to his actual mark, although he may still have gotten a little lucky on some of the balls he didn’t obliterate.

Results aside, late-2016 Buxton both felt and looked closer to his instinctive self than he had before in the big leagues. We can’t scout his smiles as accurately as his mom could when she told him shortly before September that he had to have more fun. Nor can we quantify the value of learning to relax and live with failure. But mental maturation matters, and Buxton says his took the form of finding his inner carefree kid. “At 7 and 8, you’re all about fun,” he says. “You want to go out there with your friends, you want to play, you want to make diving catches. I’ve just got to keep that mentality that I’m still 7 and 8, I’m just a professional doing it.”

Buxton also evolved by rewinding in a way we can see more easily through our TVs and web browsers. “I had a leg kick in high school, and as soon as I got drafted they got rid of it,” Buxton says. “In high school I was comfortable, I was happy. I was playing baseball and I was being myself.” Although he’d experimented with bringing it back before, he says he didn’t fully commit until after his second demotion last season, when he talked to Allen and Hunter (his former teammate, mentor, and most common comp), and told himself, “If something don’t feel comfortable, don’t do it. If you want to do it, do it.” Once he did, Buxton says, “things also started clicking for me.”

The difference is obvious if we compare the leg lift in his first major league plate appearance …

… to the much more pronounced one in his most recent trip to the plate.

Because he wasn’t working with Buxton at the time, Allen studiously avoids saying anything negative about the Twins’ decision to take the leg kick away, but his careful silence on the subject suggests that the team may have erred by trying to turn Buxton into a more conventional hitter who sprays the ball to all fields, as they once did to their detriment with David Ortiz. Buxton isn’t complaining about the loss of the leg kick. Nor will he say that the Twins may have rushed him by promoting him to the majors in 2015 when his upper-level experience was limited to 60 Double-A games. He’s just trying to extend last September’s performance.

Part of Buxton’s allure is that he doesn’t have to hit to be valuable; he was worth almost two wins last year despite playing sporadically and posting a below-average slash line. “When I was small, my dad always told me not to ever combine hitting and fielding, so him being very hard on me in that area definitely helped me out,” Buxton says. According to Statcast’s new catch probability data, he’s ranked sixth among outfielders from 2015–16 in extra catches contributed on a per-inning basis. The former high school pitcher also has a strong arm: Of the 42 fielders who primarily played center and made at least 10 max-effort throws last year, Buxton’s 94.8 mph average release ranked fifth.

But if he does hit — well, watch out, AL Central. At FanGraphs, readers are encouraged to enter their own projections for players. Those readers, many of whom have rooting interests at stake, are more optimistic than the algorithms: “FANS” projections have overshot the computer forecasts by an average of 0.6 WAR per 600 plate appearances this spring. But for Buxton, the gap between the crowd and the computers is 1.4 WAR, more than twice as large as the typical one. It’s easy to understand why: ZiPS and Steamer systems haven’t seen him run, rank first among minor leaguers, or bring back his leg kick. And they certainly haven’t seen how much he smiled last September.

If the fans are right, Buxton is about to be a four-win player. Maybe we can call that a breakout.

Thanks to Mike Petriello of MLBAM and Howard Bender of Fantasy Alarm for research assistance.