Mason Montgomery
- Winter Plan late-inning relief · 60 IP · 1.1 WAR in the role
This winter
What the Winter Plan does with Montgomery: its decisions feed, the dated moves and the briefs
The plan keeps him: late-inning relief · 60 IP · 1.1 WAR in the role.
Options left: 2 (Keystone’s estimate).
- 2027 starter hook and bullpen rolesdue Spring training · medium confidence
Rotation (Winter Plan): Paul Skenes, Jared Jones, Braxton Ashcraft, Bubba Chandler and Mitch Keller. Two times through for Mitch Keller once his medicals clear. Let Braxton Ashcraft face the order a third time (a toss-up). Let Paul Skenes face it too, pending the review of his velocity drop. Jared Jones: a 22-batter leash (about 81 pitches) after his arm injury, not an open third time; past it, decide by matchup (a toss-up). Give Bubba Chandler development innings on a 22-batter leash (about 82 pitches), once through the top of the order a third time, at about 1.0 ± 1.2 runs against a two-times-through hook (a toss-up); the goal is first two passes at .306 xwOBA or better, not a third-time skill, pending the review of his velocity drop. Ladder: Mason Montgomery and Yohan Ramírez in the late innings (within noise of each other); Evan Sisk and Luke Weaver setting up (within noise of each other). Move Evan Sisk into the leverage ladder. Move Isaac Mattson out of it.
Development · trends & plan
Tracked levels only. Monthly values; gaps mark the offseason. The number beside each line is its last month, with that month’s sample (faded under 50 PA or 150 pitches), not the season.
Plan for 2027
- 1 Diagnose low ask Find the cause of the drop in Stuff
Clear declines: Stuff 117 → 110 (2025 → 2026, MLB). Check video, medical and pitch shape before anyone sets a target.
Development Tracker
Each goal is checked when his sample can tell the target from noise: the 2027 All-Star break if it can by then, else season’s end or the sample it needs; if no single season can, it’s a lean. Coach card
Trends · MLB
Clear changes
- ▼ Stuff 117 → 110 −7 (−7 by a model that never saw him) 2025 → 2026 · MLB
Pitching · 2026 percentiles
vs. MLB pitchers with 500+ pitches · 1,169 pitches
Arsenal & Pitch Lab
Movement normalized to arm side · Keystone Stuff by pitch
| Pitch | Use | Velo | IVB | HB | Stuff | Loc | Whiff | xRV/100 |
|---|---|---|---|---|---|---|---|---|
| Four-seam46% use | 46% | 98.5 | 17.9 | +4.4 | 108 | 94 | 31% | +1.68 |
| Sinker24% use | 24% | 98.7 | 14.6 | +11.5 | 96 | 107 | 33% | +1.28 |
| Slider14% use | 14% | 89.7 | 1.5 | −1.6 | 114 | 97 | 39% | +1.48 |
| Curveball13% use | 13% | 86.5 | −6.7 | −2.2 | 117 | 96 | 35% | +0.21 |
No mix change or new pitch clears its bar. The arsenal is efficient for its shapes.
Most similar pitchers
Pitches like Montgomery: same hand, shape, slot and mix
| Similarity | Player | Stuff | ’26 WAR | ’27 proj | 2027 |
|---|---|---|---|---|---|
| 43 | Brock Burke CIN · ’96 | 100 | 0.8 | 0.5 | Free agent |
| 38 | Brent Headrick NYY · ’97 | 101 | 2.1 | 1.2 | Pre-arb |
| 37 | Jacob Latz TEX · ’96 | 113 | 2.2 | 1.1 | Arb |
| 37 | Jack Dreyer LAD · ’99 | 116 | 1.0 | 1.0 | Pre-arb |
| 35 | Erik Sabrowski CLE · ’97 | 111 | 1.2 | 0.8 | Pre-arb |
Same-handed pitchers nearest on fastball velocity and shape, arm angle, extension, pitch mix, secondary shapes, Stuff, whiff rate and workload. 2026 regulars only.
Pitch locations · 2026
Where each pitch finishes, by batter side
Where each pitch finishes, catcher’s view. The bar marks the batter’s side; the box is an average strike zone. Pitches with 40+ thrown to this side.
Contract & projection
Club control (RosterResource) · Keystone projected WAR
* projected arbitration or minimum salary. Contract Studio →
Minor leagues
MLB Stats API · public box-score data
| SeasonLevel | Level | Team | Age | G | PA / IP | PA / IP ·Line |
|---|---|---|---|---|---|---|
| 2025AAA | AAA | Durham Bulls | 25 | 9 | 9 IP | 9 IP · 2.00 ERA · 44.1% K · 2.9% BB |