KC @ BOS

Saturday · September 12, 2026·full·gamePk 824712free Saturday
refreshed 322h 13m ago both lineups confirmed

weather · Fenway Park

gametime 4:10 PM EDT · open-meteo
temperature
74°F
humidity 47%
wind
9 mph
in from LF
precip
0%
overcast
park
BOS
open · HP→CF 46°
CFHP1B3BIN
wind impact on total
-0.18 R/Gminor in

Minor wind in: -0.18 R/G vs neutral. _Green Monster blocks LF wind — wind-out games still play big to RF only; foul territory tiny_

starters · IP-weighted 2025+2026

metricRandy DobnakRHP · KCRanger SuarezLHP · BOS
xERA 20264.803.71
xwOBA 20260.3350.298
wOBA−xwOBA 2026-0.028-0.007
xERA 20255.733.14
xwOBA 20250.3640.277
Outs/TB 25-262.212.20
FIP 25-264.273.16
kwERA 25-264.623.44
K% 25-2615.2%22.9%
BB% 25-268.7%6.5%
IP 25+26 combined69.0288.0
ERA actual 20262.543.44
ERA (L4)4.094.37
WHIP (L4)1.361.37
K% (L4)19.6%12.2%
BB% (L4)7.6%9.2%
IP/gm (L4)5.505.67
L4 window08/20→09/06 (4 st) · 4/4 dates verified08/18→09/04 (4 st) · 4/4 dates verified
Stuff+ last 3 (Δ szn)84 (+1)92 (−2)
SIERA last 3 (Δ szn)3.98 (−0.70)5.42 (+1.39)
Arsenal RV/1000.420.76

away arsenal — KC

RV/100 0.42
  • Sinker—+1.60xwOBA 0.380
  • Sweeper—-0.80xwOBA 0.355
  • Changeup—-0.20xwOBA 0.263
  • 4-Seam Fastball—+1.20xwOBA 0.260
  • Slider—-1.40xwOBA 0.312

home arsenal — BOS

RV/100 0.76
  • Sinker—+0.30xwOBA 0.347
  • 4-Seam Fastball—+1.80xwOBA 0.309
  • Cutter—+1.00xwOBA 0.304
  • Curveball—+0.70xwOBA 0.214
  • Changeup—-0.30xwOBA 0.282
  • Slider—+0.10xwOBA 0.270

away · KC vs LHP

confirmed
Σ xwOBA
2.664
Σ match
2.709
Σ FRV
+19.1
#posbatterxwOBAmatchFRV
1CCarter Jensen0.3150.311+1.2
2SSBobby Witt Jr.0.3850.376+16.1
3DHSalvador Perez0.3110.322-9.1
41BVinnie Pasquantino0.3280.315+0.3
53BNick Loftin0.2940.281+0.1
62BMichael Massey0.3110.310+5.8
7RFJohn Rave0.3200.301+1.1
8LFMatthew Lugo0.1390.249-0.0
9CFKyle Isbel0.2610.244+3.5

home · BOS vs RHP

confirmed
Σ xwOBA
2.881
Σ match
3.143
Σ FRV
+23.0
#posbatterxwOBAmatchFRV
1LFRoman Anthony0.3530.364-0.2
2DHMickey Gasper0.3730.391-1.9
3CAdley Rutschman0.3370.357+11.1
4RFWilyer Abreu0.3500.392+4.8
5SSTrevor Story0.2490.281-1.4
61BNick Sogard0.3170.339+2.5
7CFJarren Duran0.2990.357+4.2
83BCaleb Durbin0.2880.300+5.0
92BAnthony Seigler0.3150.361-1.0

defense · KC catcher (Savant FRV)

Carter Jensen
  • FRV+1.2
  • framing+2.0
  • blocking-2.8
  • throwing+2.0

defense · BOS catcher (Savant FRV)

Adley Rutschman
  • FRV+11.1
  • framing+6.9
  • blocking+0.6
  • throwing+3.6

KC · Randy Dobnak

Last outing 2026-09-06 vs TOR · 6.0 IP

MetricPrior gamesLatest (Δ)Last 3
Stuff+8283(+1)84
Location+10698(-9)105
Pitching+8978(-11)90
botStf4141(-1)42
botCmd5345(-8)52
botOvr4940(-9)48
SIERA4.674.11(-0.56)3.98

Last 3 starts: 2026-08-26 → 2026-09-06. 3/3 outings have verified ratings.

Latest botERA 6.53

Prior games = unweighted average before 2026-09-06; SIERA here is an average of game ratings, not aggregate season SIERA. Stuff+ family: 100 average. PitchingBot: 50 average. Lower SIERA/botERA is better.

BOS · Ranger Suarez

Last outing 2026-09-04 vs BAL · 7.0 IP

MetricPrior gamesLatest (Δ)Last 3
Stuff+9495(+1)92
Location+106103(-3)98
Pitching+10093(-7)88
botStf4544(-1)44
botCmd5655(-1)52
botOvr5351(-2)49
SIERA4.034.33(+0.30)5.42

Last 3 starts: 2026-08-24 → 2026-09-04. 3/3 outings have verified ratings.

Latest botERA 4.49

Prior games = unweighted average before 2026-09-04; SIERA here is an average of game ratings, not aggregate season SIERA. Stuff+ family: 100 average. PitchingBot: 50 average. Lower SIERA/botERA is better.

Bullpen depth chart · per side

Derived = season-usage role from pitcher-profiles.json. Card tag = what tonight's card thinks. When they disagree, the sim picker may target wrong arms in save windows. Mean IP/app distinguishes 1-IP relievers from bulk arms.

KC · bridge (non-closer, 6-8)8 arms · kwera
0.48R / inningband [0.42–0.54]
0.113 R/PA · 0.160 R/out · worst: Anthony Gose (5.84)
BOS · bridge (non-closer, 6-8)7 arms · kwera
0.36R / inningband [0.29–0.42]
0.084 R/PA · 0.119 R/out · worst: Alec Gamboa (4.08)

KC

PitcherDerivedCardFIPK%BB%Mean IPSV/HD/GFTrend
Alex LangeCLOSERMR5.0222.511.61.0310/3/20stable
Connor ThomasBULKMR6.5113.48.53.670/3/0insufficient data
Steven CruzOPENERCL5.0225.48.61.067/5/7stable
Jose CuasMRMR2.8222.412.91.270/4/4ramping down
Nolan HoffmanMRMR3.3914.39.51.560/1/2insufficient data
Craig KimbrelMRSU4.0121.210.61.031/3/15stable
Easton McGeeMRLR6.5819.110.61.000/0/2insufficient data
Nate PearsonunknownMR3.3421.711.4—4/6/0—
Anthony GoseunknownMR3.500.03.7—0/1/0—

BOS

PitcherDerivedCardFIPK%BB%Mean IPSV/HD/GFTrend
Aroldis ChapmanCLOSERCL2.5232.310.00.9633/0/27stable
Garrett WhitlockSETUPSU2.0930.03.90.973/24/7stable
Erik MillerSETUPSU2.9234.813.90.864/13/7stable
Greg WeissertSETUPMR4.0424.07.70.961/6/4stable
Jovani MoránOPENERMR4.4326.412.41.530/5/6ramping down
Alec GamboaMRMR3.0918.37.31.601/1/5ramping up
Wyatt OldsunknownMR3.8631.59.3—0/0/0—
Raymond BurgosunknownMR4.2019.01.6—1/0/0—

glossary

Pitcher metrics

  • xERA (Savant): Statcast's expected ERA, derived from xwOBA. Strips defense/luck — what the pitcher's contact quality says he should have given up.
  • xwOBA (Savant): Expected wOBA. Treats each batted ball by exit velo + launch angle (independent of where defenders stood). Lower = better for pitcher.
  • wOBA-xwOBA (Savant): Actual minus expected. Negative = the pitcher has been UNLUCKY (better than results show). Positive = LUCKY (worse than results show).
  • Outs/TB: Outs recorded ÷ total bases allowed. Custom efficiency metric. Higher = more efficient. Starter range typically 1.5–3.0.
  • FIP: Defense-independent ERA estimator using only K/BB/HBP/HR. Removes BABIP luck. Same scale as ERA.
  • kwERA: Strikeout-and-walk-only ERA estimator. 5.40 − 12·(K−BB)/PA. Strips contact entirely. K-BB% is the most stable pitcher skill.
  • K% / BB%: Strikeouts / walks as a share of total batters faced.
  • IP (25+26 combined): Total innings across the prior + current season — defines the IP-weight on combined stats.
  • Arsenal RV/100 (Savant): Run Value per 100 pitches, weighted across the pitcher's mix. POSITIVE = stuff playing well for the pitcher. Substitute for FanGraphs Stuff+.

Batter metrics

  • AVG/OBP/SLG: Standard slash line, current season.
  • vs L/RHP AVG/OBP/SLG (PA): Same line, but only against pitchers of the hand the batter is facing tonight. PA = sample size — small samples (<50 PA) are noisy.
  • xwOBA / xBA / xSLG (Savant): Statcast expected stats for the batter, based on contact quality.
  • xwOBA(25) (Savant): Last year's xwOBA. Useful when current-year sample is thin.
  • FRV (Savant): Fielding Run Value. Range + arm + framing + blocking + DP turns. Cumulative — early-season values are small.
  • Match xwOBA: Projected weighted xwOBA against this specific pitcher's pitch mix. Per pitch (with usage %), look up batter's xwOBA vs that pitch type, weighted average.
  • Cov%: Share of opposing pitcher's pitch usage where we have direct batter-vs-pitch data. Lower coverage = less reliable matchup score.

Lineup status

  • 🟢 CONFIRMED: Posted by the team via MLB Stats API. This is the actual lineup playing.
  • 🟡 EXPECTED: Projected from the team's last 21 days of starts vs the same handedness, with current IL filtered out. Refreshes ~T-90 min before first pitch.

Data sources

  • MLB Stats API (statsapi.mlb.com): schedule, lineups, raw counting stats (K/BB/HR/IP/AVG/etc.), L/R splits.
  • Baseball Savant (Statcast): xERA/xwOBA, pitch arsenal, Fielding Run Value, expected stats. Descriptive only — no projection system.
  • Baseball Prospectus: DRC+ + PECOTA when authed.
  • Open-Meteo: Weather forecast rotated to the park.

Post-game

actual vs projected
Final total
6
1 KC · 5 BOS
Projected total
—
Delta
—
actual − projected
Band cover
—

KC

1 R

5H · 1HR · 1BB · 11K · 9LOB

OBPe 0.182 · SLGe 0.281 · K% 33.3

Their pitching

8.0 IP · 5 ER · 5 K · relief 2.3 IP · 4 arms

BOS

5 R

10H · 0HR · 1BB · 5K · 10LOB

OBPe 0.353 · SLGe 0.438 · K% 14.7

Their pitching

9.0 IP · 1 ER · 11 K · relief 2.0 IP · 3 arms

KC · standout lines

big nights
  • Carter Jensen (C) · 1-4 | HR, 2 K, RBIHR
tough nights
  • Nick Loftin (RF) · 0-4 | 3 K0-for-4 · 3 K
  • Matthew Lugo (LF) · 0-3 | 2 K0-for-3 · 2 K

BOS · standout lines

big nights
  • Nick Sogard (1B) · 2-3 | 2 2B, HBP, RBI4 TB
tough nights
  • Jarren Duran (CF) · 0-4 | K0-for-4
sources · MLB Stats API · Baseball Savant · Baseball Prospectus · Open-Meteo · reference, not picks