Every baseball season stretches the limits of one’s attention. There’s too much happening, in too many places, all at once. Especially once the outliers of April’s starting stretch fade into a pack of competing performers, it can be tough to keep track of all of MLB’s revelatory individual seasons.
So before August turns to September and the tight playoff races drown out everything else, let’s take a careful look at the leaderboards and highlight nine stars of 2023 whose big numbers might sneak up on you.
(All stats are current through Thursday, Aug. 17. WAR and value metrics from FanGraphs.)
Bobby Witt Jr., Kansas City Royals shortstop
2023 stats of note: 23 homers, 34 steals, 120 OPS+, +10 Fielding Run Value (top-10 in MLB), 4.7 WAR
The No. 2 overall pick in the 2019 draft, Witt’s rookie season in 2022 had a little bit of shine (20 homers, 30 steals) that failed to cover for a slew of worrisome dents. A sub-.300 on-base percentage and extreme defensive struggles while he split time between third base and shortstop were enough to raise eyebrows about Witt’s future potential as that year’s No. 1 pick, the Baltimore Orioles’ Adley Rutschman, hit the ground running.
Well, consider those concerns at least mostly dispelled. Witt’s full-season offensive numbers still won’t have anyone drooling, but since July 1 — even with the Royals’ season long in the tank — he has been one of the game’s best position players, slashing .342/.376/.658 with 11 homers and 11 steals.
Perhaps more importantly, his defense has not just improved but flipped to full-on spectacular. Allowed to play shortstop full-time, Witt rates among the top-10 defenders in the game by Statcast and has his share of spectacular plays to back it up.
— Yahoo Sports MLB (@MLByahoosports) August 11, 2023
Ha-Seong Kim, San Diego Padres second baseman
2023 stats of note: .281/.373/.440, 15 homers, 27 steals, 12.3% walk rate
There were no questions about Kim’s defense — other than perhaps where he’d play it. The third-most famous shortstop on the San Diego Padres, Kim has thrived as the team’s full-time second baseman. By WAR, he is not only the most valuable of the trio (which includes veteran shortstop Xander Bogaerts and right-field convert Fernando Tatis Jr.) but also the most valuable player on the Padres overall.
You might think that’s more a knock on the disappointing Padres than a win for Kim, but he has continued to adjust and climb the rungs of productivity in his third season since coming to MLB from the KBO. He’s probably managing a bit more power than underlying metrics would predict, but there’s no arguing against his overall improvement. In 2021, Kim batted just .157 against breaking pitches. In 2022, that rose to .216, and this season, he has mashed them to the tune of a .317 batting average and an even lower whiff rate than he has against heaters. Among a lot of splashy moves with less certain outlooks, signing Kim looks like a win for the Padres.
Jarren Duran, Boston Red Sox outfielder
2023 stats of note: .299/.350/.492, 8 homers, 23 steals
Triston Casas, Boston Red Sox first baseman
2023 stats of note: .256/.357/.488, 20 homers, 124 OPS+, 91st percentile expected slugging percentage
The Red Sox are still grasping at the fringes of the playoff picture, but Duran and Casas (along with some upward-facing arrows on the pitching staff) are the best evidence yet for Chaim Bloom’s slow, often-frustrating build toward sustainable relevance. These players are also classic examples of the breakout stories that sometimes go unnoticed when they don’t take off in April.
Duran and Cases both took some lumps in their first tastes of the majors (especially Duran), but high expectations are now starting to meet reality. Duran, a fleet-footed outfielder, rates as one of MLB’s 12 most valuable base runners this season, despite playing in only 99 games. Casas, a huge, left-handed slugger, has begun displaying any-part-of-any-park power. Since June 1, he has ripped off a .302/.393/.583 line that stacks up with some of the game’s best hitters.
J.P. Crawford, Seattle Mariners shortstop
2023 stats of note: 125 OPS+, 10 homers, 89 mph average exit velocity
The 28-year-old shortstop has provided the Mariners a much-needed offensive boost this season by adding pop to a profile long centered on patience and defense. Pre-2023 Crawford deserves a pat on the back for consistently running above-average on-base percentages without ever popping 10 homers in a season, but this season’s version is better.
Seeking improvement, Crawford worked out at Driveline this past offseason, tweaking his setup at the plate to tremendous effect. His average exit velocity has spiked from a bottom-of-the-barrel 85.1 mph in 2022 to 89 mph in 2023, which explains how he has already beaten his previous career high in home runs.
Tanner Bibee, Cleveland Guardians starter
2023 stats of note: 108 2/3 innings, 2.90 ERA, 141 ERA+, 0.83 HR/9 (top-10 in MLB)
A fifth-round pick in 2021, Bibee torched the minor leagues on the way to a late April callup this year. Coming over the top in a flash, Bibee runs his fastball up there at 95 mph, but the slider is the star here. An 85 mph mirage that he throws all over the zone, the pitch flies in the fastball tunnel just about as well as any breaking ball in baseball, making for peak deception.
Accordingly, it has the lowest hard-hit rate of any starting pitcher’s slider (min. 100 PA). This season’s Guardians might fail to capitalize on a weak AL Central, but Bibee is proof they have the pitching mojo to be a threat in the coming seasons.
Pablo López, Minnesota Twins starter
2023 stats of note: 147 2/3 innings, 118 ERA+, career-best 30.0 K%
The 27-year-old lefty hasn’t been overlooked so much as overshadowed. López joined the Twins in a fascinating offseason trade that sent Luis Arráez to the Miami Marlins. Arráez has amazed by chasing a .400 batting average far longer than anyone else had in recent seasons and helping the Marlins make a surprise bid for a wild-card spot.
López can’t claim anything quite that historic, but his first season in Minnesota has been wildly encouraging. With a slider added into the mix alongside his curveball and trademark changeup, he is running strikeout and walk rates that rank among MLB’s elite and portend even better top-line results ahead.
Braxton Garrett, Miami Marlins starter
2023 stats of note: 122 innings, 3.91 ERA, 111 ERA+, 20.7 K-BB% (top-12 in MLB)
One of the pitchers who made López expendable for the Marlins, Garrett has a terrific, Frisbee-like slider that hitters miss on more than 43% of their swings. He has maintained strong, surprising results from a partial season in the rotation in 2022 — but not by standing still.
Garrett’s 2023 success owes plenty to that slider but perhaps just as much to experimentation. He has deemphasized his four-seam fastball in favor of a sinker and a cutter that allow him to more confidently attack right-handed hitters.
The next step for Garrett is gaining the consistency to avoid the occasional implosion. He’s running that 111 ERA+ despite a May start in which he allowed 11 earned runs and a three-inning, six-run affair last month.
Gregory Santos, Chicago White Sox reliever
2023 stats of note: 57 innings, 3.00 ERA, 2.61 FIP, 53.3% ground-ball rate
There are, uh, not a lot of positive things to say about this Chicago White Sox season, but Santos counts as a bright spot. Just 23 years old, the high-octane righty has tamed control issues and won high-leverage work with a tough sinker-slider combo. Firing the pitches in roughly equal measure, Santos makes hitters contend with a 99 mph sinker bent on burning worms and a darting slider that averages 92 mph itself.
It’s still only 57 innings of pitching, so there’s a chance that Santos’ command problems pop up again, but he has a strong formula for success between top-level velocity and the assurance of ground-ball tendencies.