Players / Player profile
BOS · DH

Jahmai Jones

Age 29 B/T R/R 5′10″, 210 lb USA MLB debut 2020
40-man
  • Boston’s roster as it stands on the 40-man, off the 26-man (call-up depth)
  • Trade read Available at a price: BOS 76% playoff odds; control through 2030.
xwOBA .328 wOBA .309
2026 fWAR −0.5
Projected 2027 WAR 0.3 Keystone Marcel+ at 306 PA

Hitting · 2026

181 PA: percentiles need 300+, so values only

xwOBA .328 xwOBA: .328
Swing decisions +0.59 Swing decisions: +0.59
Contact value −0.25 Contact value: −0.25
Bat speed 73.3 Bat speed: 73.3
Squared-up / swing 17% Squared-up / swing: 17%
Blasts / swing 10% Blasts / swing: 10%
EV90 106.3 EV90: 106.3
Barrel % 10.9% Barrel %: 10.9%
Chase % 29.7% Chase %: 29.7%
Zone contact 76.8% Zone contact: 76.8%
Strikeout % 32.0% Strikeout %: 32.0%
Walk % 9.4% Walk %: 9.4%

Platoon splits · swing path

By pitcher handedness

vsPAwOBAxwOBAK%BB%ChaseDecisionsContact
LHP156.339.35331%11%28%+0.82+0.64
RHP25.113.16040%0%42%−0.87−4.30
Attack angle
14.9° (57% in 5–20°)
Attack direction
−10.5°
Swing length
7.7 ft
Fast-swing rate
32%
Pull-air %
29.4%
Hard-hit %
43.6%
Slash · wRC+
.206/.298/.369 · 88

Zone map · 2026

Where he does damage, and where to pitch him

+2.4−0.2−0.9+0.4+1.0+0.3−2.0+0.7−3.1+0.3+0.7−1.0+1.4−1.9−0.7+0.7−2.8+3.0+0.7+1.5+0.1+1.0−2.5−2.3+0.8RHB

Does the most damage down over the middle (+3.0 vs. league per 100; 1.3 standard errors on 50 pitches, inside the noise for the best of nine cells).

Weakest up and away (−3.1), but only 1.3 standard errors from average on 33 pitches: no in-zone spot to attack yet.

Runs per 100 pitches vs. an average RHB: better · worse. Catcher’s view · 633 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).

Most similar hitters

Swings like Jones: bat path, contact quality and approach

SimilarityPlayerxwOBA’26 WAR’27 proj2027
72Dalton Rushing LAD · ’01.3361.11.0Pre-arb
67Kazuma Okamoto TOR · ’96.3283.01.7Signed $17.3M
64Nolan Gorman STL · ’00.278−0.5−0.1Arb
63Jorge Soler LAA · ’92.294−0.6−0.5Free agent
57Brandon Lowe PIT · ’94.3314.92.5Free agent

Brandon Lowe (similarity 57, 2.5 WAR projected for 2027) is a free agent this winter: a similar swing available without trading talent, at a free agent’s price. Opportunity Finder →

Nearest neighbours on bat speed, swing length, attack angle, squared-up and blast rates, EV90, barrels, pull-air, chase, zone contact, K% and BB%. 2026 regulars only.

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
LF −3.5 −11.0
RF −6.5 −14.0
Outs Above Average by position
SeasonPosOAARangeArm, DPRunsBatters
2026RF000.00.044
2026LF−3−20.0−2.0124
2025LF−1−1−0.4−1.4158
2025RF−1−1−0.4−1.4212
20243B000.00.026
20242B+10+0.1+0.186
2024RF00+0.1+0.188
2024LF00+0.1+0.1116
20232B000.00.049

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 at LF)
2026 · LF In (charging) −1Back 0Toward 3B line −1Toward 1B line −1vs. RHH −1vs. LHH −2
Tools (percentile among MLB fielders)
Arm strength —
Sprint speed 28.5 ft/s · 81st
Reaction +1.0 ft · 86th
Burst +0.6 ft · 71st
Route −0.4 ft · 26th
Catch difficulty (latest season)
PlayMadeChancesRate
★★★★★00—
★★★★00—
★★★00—
★★020%
★010%
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 0.3 WAR Arbitration $1.1M*
2028 0.1 WAR Arbitration $1.2M*
2029 −0.2 WAR Arbitration $1.4M*
2030 −0.5 WAR Arbitration $1.4M*

* projected arbitration or minimum salary. Contract Studio →

Minor leagues

MLB Stats API · public box-score data

SeasonLevelLevelTeamAgeGPA / IPPA / IP ·Line
2025AAAAAAToledo Mud Hens2752205 PA 205 PA · .276/.392/.482 · 6 HR · 22.4% K · 11.7% BB

ABS challenges · 2026

Baseball Savant

As batter 50% 4/8 won · +0.1 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.