The NBA hands out the Most Improved Player award at the end of each season to the player who, well, improves the most. There is no concrete criteria for the award, thus leading to myriad interpretations and calculations, but it's generally given to a player who exceeds expectations and past production in a substantial, sometimes completely unforeseen way.
Most often, it's a younger star finding his sea legs, but sometimes a proven vet sneaks into the conversation with an unexpected late-career surge. This is an award that can (and should) be mapped onto MLB: There are so many breakout stars worthy of acclaim, and yet the league will do very little to hand them their flowers. All-Star berths and MVP votes are nice, but wouldn't a piece of hardware be even better? We all love a trophy.
As for how to determine this award, well, it's really in the eye of the beholder. Some will value the sheer gap between one's 2024 impact and 2025 impact, whether it's measured in fWAR or a more basic statistical cocktail. Others will take a more holistic approach, charting the arc of an entire career rather than two individual seasons. Some will argue that second-year players shouldn't win the award, as growth is expected after your rookie campaign. It's a case many an NBA writer has made.
For our purposes, let's just detail five players who made a big leap — expected or unexpected — with favor to the absolute most valuable. Going from star to MVP candidate is a more consequential leap than going from average Joe to All-Star, in my book. Anyhow ... let's dive in.
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Honorable mentions: SS Geraldo Perdomo (Arizona Diamondbacks), LHP Cristopher Sánchez (Philadelphia Phillies), 3B Maikel Garcia (Kansas City Royals)
5. OF Kyle Stowers, Miami Marlins
After struggling to break through at the MLB level for a couple years in Baltimore, Kyle Stowers was dealt to the Miami Marlins midway through last season. The results didn't come immediately in 2024, but he has broken out in a big way in 2025. Stowers was Miami's lone All-Star this year, and he has been the foundational star of a much-improved lineup, helping to keep the Marlins competitive in a loaded division.
Stowers went from a .601 OPS in 209 plate appearances last season to a .912 OPS with 25 home runs and 73 RBI through 457 plate appearances in 2025. Suddenly the 27-year-old, who was dealt to Miami in exchange for reliever Trevor Rogers, is a genuine face of the franchise. It can be easy to overlook the Marlins, but if there is a case for optimism regarding their future, it starts with Stowers. He is a genuine anchor point in the middle of the lineup.
We will see how sustainable Stowers' production is, but all the metrics point to genuine stardom. He's in the 93rd percentile for hard-hit rate and the 98th percentile for barrel rate. He still strikes out a ton, but there's even more room to grow, and he's making the most of his contact (.288 average). While not an elite glove in the outfield, Stowers has a strong arm. He's generally a positive presence across the board.
Stowers captures the essence of any Most Improved Player award. He went from an afterthought to Miami's centerpiece. Hopefully the Marlins can do his improvement justice by building up the roster next season rather than falling back into the cycle of mediocrity.
4. RHP Hunter Brown, Houston Astros
After stumbling through his rookie season, Hunter Brown's sophomore campaign in 2024 was a tale of two halves. He came out of the gate extremely shaky, but settled in after the All-Star break and delivered ace-level value down the stretch. He has blossomed fully in 2025, emerging as the Houston Astros' most dependable and dominant starting arm at 27 years old.
Brown checks just about every box for an ace. He won't compete with Tarik Skubal or Garrett Crochet for the AL Cy Young award, but he's right on the outskirts of that conversation. Through 26 starts, he has a 2.37 ERA and 1.01 WHIP with 177 strikeouts in 155.2 innings.
He leans heavily on his high-90s fastball, but Brown also generates a ton of ground-ball contact with a deceptive sinker. He can pepper in a curveball, changeup and even the occasional slider, giving him plenty of options for every at-bat. It's rare to find a strikeout pitcher like Brown who keeps hard contract to such a minimum. He can win in a variety of ways, whether it's blowing through the opposition with raw power or playing the finesse game and letting his defense carry the day.
Brown went from something of a mystery box to Houston's No. 1 ace for the foreseeable future. If that isn't worth consideration for an award like this, I'm not sure what is.
3. DH Kyle Schwarber, Philadelphia Phillies
Kyle Schwarber is a highly decorated 32-year-old — a three-time All-Star, a former Silver Slugger and a World Series champ. And yet, somehow, he has figured out how to take it to the next level in his 11th MLB season. He deserves major credit, too, as the Philadelphia Phillies wouldn't be half as compelling as a National League contender without Schwarber rocketing into the MVP debate.
He probably won't topple Shohei Ohtani when the final MVP votes are cast, but there'd be an equally strong case for Schwarber in this category. He has always hit for power, but he just set his career-high with 49 home runs in the final week of August. His four-homer performance on Thursday was an exclamation mark, but it's hardly an aberration. Schwarber has been on a bee line toward MLB history all season.
In addition to his incredible slugging, Schwarber's current mark is tied with last season for the highest batting average of his career (.248). It's a bit too far to say he's hitting for contact, but Schwarber is cutting down on strikeouts and still commanding an absurd volume of walks. He's seeing all areas of the plate better and operating with dramatically improved discipline.
Schwarbs was maybe the fourth- or fifth-most valuable player on the Phillies last season. Now he might be the second-most valuable player in the entire National League, even without setting a foot in outfield (save for a couple spot starts when Philly's primary outfielders are resting). His ability to both command the strike zone and hit with unmatched power is special. We are witnessing one of the great offensive seasons in recent history.
2. OF Pete Crow-Armstrong, Chicago Cubs
Pete Crow-Armstrong was perfectly fine as a rookie. He showed a little bit of pop and was utterly stupefying in the outfield, where he quickly climbed the ranks of MLB's best defenders. Factor in his speed on the base paths, and PCA was undeniably a valuable player, even with a .670 OPS that kept him pigeonholed in the No. 9 spot in the lineup.
It took a while for Craig Counsell to accept Crow-Armstrong as a genuine bopper in the middle of the order, but the 23-year-old has forced a change with his incredible output this season. He has skyrocketed into the MVP conversation with an .800 OPS and 28 home runs to go along with 31 stolen bases and a league-leading 20 outs above average in the outfield.
The bat has cooled off a bit since the All-Star break. PCA still chases way too many pitches out of the zone and his strikeout rate has spiked as a result. That will probably prevent him from winning this imaginary award, but the speedy center fielder still deserves his flowers. PCA has been more or less the driving force behind the Chicago Cubs' ascent in the NL Central. Chicago is going to (finally) crack the postseason, with a chance to go deep into October. That all starts with PCA's absurd five-tool skill set.
Many will argue that a sophomore can't or shouldn't win this award, but if we are going by what it says on the tin — the "most improved" player — PCA absolutely deserves a shout. It does not say the "most improved player with three-plus years of MLB experience," does it?
1. C Cal Raleigh, Seattle Mariners
Aaron Judge still holds a slight edge in fWAR (7.5) compared to Cal Raleigh (7.3). Since one plays for the New York Yankees and the other plays for the Seattle Mariners, we can probably guess which will end up winning AL MVP honors. (Judge is very deserving, but come on! Have some fun!) That said, Raleigh has made quite the case for himself, leading MLB with 50 homers and leading the American League with 107 RBI.
That is the third-most home runs in a single season for a switch hitter in MLB history, and he still has another month to catch Mickey Mantle at 54. It's the most all time for a catcher, again with another month left to cushion his lead. This has been a historic offensive campaign for Raleigh. More than a dominant slugger, he's also an excellent defensive catcher, in the 89th percentile for pitch framing.
While Judge has the more valuable offensive profile, he's a resounding negative in the field (and has spent the past few weeks as a DH as he recovers from an elbow injury). When looking holistically at each individual's contributions to their team — not to mention the talent around them and their team's ability to win independent of their contributions — it's not hard to build a case for Raleigh.
He still strikes out a lot, and a recent cold spell generated ample concern about how Raleigh's slugging might translate in October, but this has been a singularly impressive season at a position where even league-average bats are hard to come by. Raleigh has been a great catcher for years now, but this season launched him to a whole new level of stardom. If he's not going to win MVP, he should at least be taking home a MIP trophy.