Players / Player profile
ATH · C

Brian Serven

Age 31 B/T R/R 6′0″, 207 lb USA MLB debut 2022
40-man
  • The Athletics’ roster as it stands bench · 220 PA · 0.5 WAR in the role
xwOBA .278 wOBA .258
2026 fWAR 0.0
Projected 2027 WAR 0.0 at 243 PA · 0.5 in his 2027 role

Hitting · 2026

86 PA: percentiles need 300+, so values only

xwOBA .278 xwOBA: .278
Swing decisions −0.41 Swing decisions: −0.41
Contact value −0.69 Contact value: −0.69
Bat speed 70.7 Bat speed: 70.7
Squared-up / swing 24% Squared-up / swing: 24%
Blasts / swing 9% Blasts / swing: 9%
EV90 103.6 EV90: 103.6
Barrel % 8.5% Barrel %: 8.5%
Chase % 31.6% Chase %: 31.6%
Zone contact 75.9% Zone contact: 75.9%
Strikeout % 24.4% Strikeout %: 24.4%
Walk % 4.7% Walk %: 4.7%

Platoon splits · swing path

By pitcher handedness

vsPAwOBAxwOBAK%BB%ChaseDecisionsContact
LHP35.273.27220%3%31%−0.95−0.41
RHP51.248.28227%6%32%−0.05−0.83
Attack angle
11.9° (57% in 5–20°)
Attack direction
+1.3°
Swing length
7.4 ft
Fast-swing rate
6%
Pull-air %
18.6%
Hard-hit %
30.5%
Slash · wRC+
.175/.224/.375 · 55

Zone map · 2026

Where he does damage, and where to pitch him

0.0−0.9+2.0−0.2−0.2−0.5−2.6−1.4+3.9+0.7+0.6−2.4+2.6−2.9−1.1+0.2+2.3−3.5−2.0+1.1−0.2−0.5−1.8−1.0−0.2RHB

Does the most damage up and away (+3.9 vs. league per 100; 1.9 standard errors on 14 pitches, inside the noise for the best of nine cells).

Weakest down over the middle (−3.5), but only 1.6 standard errors from average on 23 pitches: no in-zone spot to attack yet.

Runs per 100 pitches vs. an average RHB: better · worse. Catcher’s view · 302 pitches · faded cells are within one standard error of average. A spot is called only when it is farther from average than the best or worst of nine average cells gets 95% of the time (set from the league’s own pitches: about 3 standard errors above, 2 below).

Fielding

2027 rating at every position he can play · OAA by position · range by direction · tools. Same engine as the Fielding Lab and the Winter Plan.

2027 rating by position · best fit first, on the total with the position’s worth
C +0.5 +13.0
Outs Above Average by position
SeasonPosOAARangeArm, DPRunsBatters
No MLB fielding yet.

Runs = range plus his arm and double-play runs spread over his positions by outs (Fielding Run Value, from 2023): what the rating counts.

Range by direction (OAA)

No directional data (needs a qualified season at one position).

Tools (percentile among MLB fielders)
Arm strength —
Sprint speed 26.0 ft/s · 17th
Zone rating (Keystone expected outs)
SeasonZoneBallsOuts vs. exp.
Too few balls in his zone.

The zone rating counts every ball hit to his part of the field while he played there, his club’s positioning included; Savant OAA uses his actual starting spot and is the better individual grade. They agree best in the outfield. See the model card.

Compare in the Fielding Lab →

Contract & projection

Club control (RosterResource) · Keystone projected WAR

2027 0.0 WAR —
2028 −0.3 WAR —
2029 −0.6 WAR —
2030 −0.8 WAR —

Contract Studio →

Minor leagues

MLB Stats API · public box-score data

SeasonLevelLevelTeamAgeGPA / IPPA / IP ·Line
2026AAAAAALas Vegas Aviators3161262 PA 262 PA · .308/.401/.538 · 9 HR · 26.0% K · 11.8% BB
2025AALakeland Flying Tigers30727 PA 27 PA · .217/.333/.348 · 0 HR · 40.7% K · 11.1% BB
2025AAAAAAToledo Mud Hens3062233 PA 233 PA · .232/.335/.313 · 3 HR · 25.3% K · 12.0% BB

ABS challenges · 2026

Baseball Savant

As batter 0% 0/1 won · −0.2 runs
As catcher 67% 12/18 won · −0.4 runs
Keystone is an independent portfolio project. It is not affiliated with Major League Baseball or any club. Data: MLB Stats API, Baseball Savant, FanGraphs. Used under their terms for individual, non-commercial use.