Players constantly surprise us with their performance throughout the season. But at this stage, with a little more than one month remaining, we have a much better idea of who meaningfully exceeded expectations.

Expectations are pretty subjective though, so for our purposes, we've compared players against their ZiPS projections, the system created by FanGraphs' Dan Szymborski which draws primarily on recent performance (for most, their last four seasons) and aging curves, and it's generally considered one of the most accurate projection models for Major Leaguers.

Here is a look at eight players who have significantly outplayed their 2023 preseason projections in terms of FanGraphs' wins above replacement (WAR) and what's contributing to their unexpected levels of success.

All stats are through Thursday's games.

Cody Bellinger, 1B/OF, Cubs
Projected: 2.5 fWAR, .714 OPS
Actual: 3.8 fWAR, .916 OPS

Bellinger, of course, has performed at or above this level in the past -- he had a 161 wRC+ and 7.8 fWAR in his NL MVP-winning 2019 season. But the projections couldn’t ignore just how difficult the past few seasons were for the 28-year-old. Now, though, Bellinger's comeback is ongoing and shows no sign of stopping (if anything, it seems to be ramping up.) For most players, a jump in offensive production comes from making better contact. For Bellinger, it hasn't -- his hard-hit rate has fallen, but his whiff rate has, too, with Bellinger improving from the 33rd percentile in 2022 to the 82nd in '23. And, after struggling mightily with breaking or offspeed pitches for several seasons, he's seeing non-fastballs better than he ever has (.321 BA, .584 SLG).

Bryson Stott 2B, Phillies
Projected: 2.0 fWAR, .688 OPS
Actual: 3.6 fWAR, .785 OPS

Stott only debuted last season, so his breakout exceeding his ZiPS projections isn't too unusual, but his rapid development into a viable Major League contact hitter (who also has 12 home runs) is notable. He's made vast improvements against fastballs -- usually a pretty strong benchmark when evaluating young players -- having gained 123 points on his average (to .332) and 155 on his SLG (to .479). He hasn't sacrificed anything in terms of discipline, either, as his whiff rate (15.2%) ranks in the 95th percentile. Stott has tightened up his defense considerably as well -- he has +9 Outs Above Average after being worth -1 in 2022.

Bobby Witt Jr., SS, Royals
Projected: 3.4 fWAR, .775 OPS
Actual: 5.1 fWAR, .826 OPS

Witt's rookie season was hardly a disappointment for the Royals, but he clearly had plenty of room for improvement. And while his actual numbers don't look like a radical improvement on his projections, his underlying skills have come a long way -- his hard-hit, barrel rates and expected wOBA have all spiked alongside a dip in whiff rate in his sophomore season. He, like Stott, has also caught up to big league fastballs; after hitting .239 with a .422 slugging percentage against all fastballs in his rookie campaign, he's hitting .307 and slugging .557  in 2023.

Witt's improvements, 2022-'23
Expected wOBA: .313 -> .375
Hard-hit rate: 38.6% -> 45.2%
Barrel rate: 8.7% -> 11.7%
Whiff rate: 25.2% -> 23.8%

His 2023 fWAR is also getting a major boost from his improved defense as well -- as of Wednesday, he leads the AL with +13 Outs Above Average, having been worth -11 in 2022 (by DRS, Witt cost the Royals 18 runs with his defense at shortstop in 2022 and another four at third base -- this year he's broken even.)

Christian Yelich, OF, Brewers
Projected: 2.4 fWAR, .758 OPS
Actual: 3.9 fWAR, .826 OPS

A player's past three seasons are heavily weighted when it comes to ZiPS projections, which we can see in Yelich's case. From 2020-22, he hit .243/.358/.388, an OPS of .746. But this year, his hard-hit rate has crept back over 50% for the first time since 2020, and his swing rate, which tanked between his second-place NL MVP finish in 2019 and the abbreviated 2020 season (-10.6 points), has finally recovered. On the surface, it doesn't look like much has led to Yelich's comeback, but gradual improvements don't have to be stark to make a difference. And that comeback has been huge for the first-place Brewers.

Lane Thomas, OF, Nationals
Projected: 1.1 fWAR, .730 OPS
Actual: 2.5 fWAR, .806 OPS

Thomas, who came into the season with a career .726 OPS (105 OPS+), got plenty of playing time with the Nationals last season but never quite realized his potential as a former Top 10 prospect in the Cardinals' system. Now he's enjoying a pretty impressive season in relative obscurity, so we ought to give him his due. He was projected for 15 homers in 137 games. Through 127, he already has 20. His hard-hit rate is up by 6 points. And he has -- you might be sensing a theme among breakout seasons -- also improved significantly against fastballs, hitting .308 with a .512 SLG after posting a .247 BA and .410 SLG in 2022. He's done this, interestingly, all while walking less and striking out more than ever -- but whatever works.

Blake Snell, LHP, Padres
Projected: 2.7 fWAR, 3.61 ERA
Actual: 2.7 fWAR, 2.73 ERA

Snell had never managed to recapture the form that won him the 2018 AL Cy Young Award, having posted a 3.85 ERA (104 ERA+) from 2019-22. Seemingly out of the blue, the 30-year-old is working on what has become a campaign for his second Cy Young Award, and an unusual one at that. Despite working on his highest BB/9 rate since his rookie season (5.1) -- which goes far beyond passing as "effectively wild" -- he's improved on his ground-ball rate (+6.6 points), hard-hit rate (-6.4 points) and average exit velocity (-3.2 mph). Meanwhile, his curveball, wild as it may be, is back to being a knockout pitch. This season, opponents are hitting .085 against it with a .161 SLG. Just for good measure, by run value, it's been the second-most valuable curveball in baseball (+16 runs).

Kyle Bradish, RHP, Orioles
Projected: 0.8 fWAR, 4.69 ERA
Actual: 2.4 fWAR, 3.03 ERA

Spare a thought for Bradish, whose breakout season is flying a bit under the radar on the Orioles' powerhouse roster. After a brutal rookie campaign in which he posted a 4.90 ERA, the right-hander has been Baltimore's best starter as the club surges toward a potential AL East title in 2023. Bradish has exceeded his projections for his BB/9 (3.8 projected, 2.5 actual) and HR/9 rates (1.3, 0.9) and has found further success by overhauling his repertoire, dropping his four-seamer usage by just over 20 points, making his slider his primary pitch. Then there's the massive improvement to his curveball, which is the third-most valuable pitch in baseball by run value (+14) and has generated a .161 opponents' SLG.

Yusei Kikuchi, LHP, Blue Jays
Projected: 0.5 fWAR, 4.49 ERA
Actual: 2.0 fWAR, 3.52 ERA

Kikuchi came into 2023 with a 5.02 ERA in four seasons since coming over from Japan, where he starred in Nippon Professional Baseball. After he posted a career-high 5.19 ERA in his first season with the Blue Jays, his ZiPS projections for this year looked almost optimistic. Well, so much for that. His BB/9, projected for 3.9, currently sits at 2.4. His hard-hit rate is down 7.5 points, and his barrel rate another 6.3 -- all three are reflected in his career-low 1.23 WHIP (projected at 1.40). If one pitch has made the difference for Kikuchi, it's been his slider, against which his opponents are hitting .219 with a .399 SLG (.289 BA, .612 SLG in 2022). While Toronto's offense has not lived up to expectations, Kikuchi has been part of a remarkably stable Blue Jays rotation that has excelled despite Alek Manoah's struggles.