bayesRatings

Royals at Mariners

MLB · Sunday, May 3 · 3:10 PM CT · T-Mobile Park · Final KC 4 – SEA 1
← MLB / May 3

Final Box Score

from the game summary
Team123456789THE
KC000301000480
SEA001000000141
Team box
KC·SEA
8
hits
4
0
home runs
0
5
walks
3
7
strikeouts
10
123
pitches thrown
155
0
errors
1
Top hitters
PlayerTeamH-ABRHRRBI
Isaac CollinsKC2-2002
Kyle IsbelKC2-3000
Vinnie PasquantinoKC2-5100
Josh NaylorSEA1-4001
Bobby Witt Jr.KC1-5100
Maikel GarciaKC1-5000
Pitchers
PitcherTeamIPHERBBK
Kris Bubic (W)KC7.04127
Daniel Lynch IV (S)KC1.10003
Luis Castillo (L)SEA6.06425

For context, not in our forecast.

Game Flow

score margin
SEA +3
KC +3
123456789
largest lead: SEA 1 · KC 3lead changes: 1

For context, not in our forecast.

Final · our forecast was KC 46%, SEA 54% · Updated May 3

Expected margin
SEA by 0.6
Expected score
SEA 4.4 – 3.8 KC
Expected total
8.2
RoyalsThe matchupMariners
+118Our fair odds−118
3.8Expected runs4.4
−0.02Power rating+0.07
4.1Runs / game4.2
4.7Allowed / game4.0
8.0Hits / game7.7
1.00Home runs / game1.12
3.5Walks drawn / game3.9
14−19Season record16−18
7−3Last 106−4

Prediction markets

Kalshi · Polymarket US · ProphetX · Novig
KC chance · SEA chance
Our model fair45.9%54.1%
Kalshi51.7%51.7%
Polymarket USno two-sided price
ProphetXno two-sided price
Novigno two-sided price
Full price table
TeamOur modelfairKalshipre-game · 3:10 PM CTPolymarket US ProphetX Novig 
Moneyline
KCKansas City Royals+11846%−10751.8%———
SEASeattle Mariners−11854%−10751.8%———
SpreadSEA by 0.6
KCKansas City Royals+0.6our margin————
SEASeattle Mariners−0.6our margin————
Totalwe expect 8.2
Over8.2our total————
Under8.2our total————

These are each venue’s last prices before the start (Kalshi’s moneyline: its pre-game close). Odds are the price to buy that side now, taker fee included; the small percent is the implied chance of that same price. Highlighted is the best price in the row among venues on the same line. — means not listed (hover or tap for why). A market price is not the true chance of winning.

Margin range

Seattle Mariners by 0.6 expected
Kansas City Royals by 13 runs: <1%Kansas City Royals by 12 runs: <1%Kansas City Royals by 11 runs: <1%Kansas City Royals by 10 runs: <1%Kansas City Royals by 9 runs: 1%Kansas City Royals by 8 runs: 1%Kansas City Royals by 7 runs: 1%Kansas City Royals by 6 runs: 2%Kansas City Royals by 5 runs: 3%Kansas City Royals by 4 runs: 5%Kansas City Royals by 3 runs: 6%Kansas City Royals by 2 runs: 9%Kansas City Royals by 1 run: 16%Seattle Mariners by 1 run: 14%Seattle Mariners by 2 runs: 11%Seattle Mariners by 3 runs: 8%Seattle Mariners by 4 runs: 6%Seattle Mariners by 5 runs: 5%Seattle Mariners by 6 runs: 3%Seattle Mariners by 7 runs: 2%Seattle Mariners by 8 runs: 2%Seattle Mariners by 9 runs: 1%Seattle Mariners by 10 runs: 1%Seattle Mariners by 11 runs: 1%Seattle Mariners by 12 runs: <1%Seattle Mariners by 13 runs: <1%
← KC wins bySEA wins by →
Seattle Mariners wins by 2 or more41%
Seattle Mariners wins by 3 or more30%
Kansas City Royals wins by 2 or more30%
Decided by one run30%

Centered on the expected margin above; shape from each team's expected runs, with ties after nine settled as one-run games, matched to 14,698 past MLB games.

Total range

8.2 expected
1 runs: 2%2 runs: 2%3 runs: 8%4 runs: 6%5 runs: 12%6 runs: 8%7 runs: 12%8 runs: 8%9 runs: 10%10 runs: 6%11 runs: 7%12 runs: 4%13 runs: 4%14 runs: 3%15 runs: 3%16 runs: 1%17 runs: 1%18 runs: 1%19 runs: 1%20 runs: <1%21 runs: <1%22 runs: <1%
Total runs, both teams
Total over 6.563%
Total over 8.543%
Total over 10.526%
Total from 7 to 1037%

Centered on the expected total above; shape from each team's expected runs, with ties after nine settled as one-run games, matched to 14,698 past MLB games.

Starting Pitchers

from the box score
KCKris Bubic SP · last 3 starts: 15.2 IP, 5.17 ERA, 12 Kstarted
SEALuis Castillo SP · last 3 starts: 15.1 IP, 5.87 ERA, 12 Kstarted

Starting pitchers are part of our forecast.

Rest and Schedule

before this game
KC·SEA
May 2 at SEA
last game
May 2 vs KC
0 days
days of rest
0 days
6
games in last 7 days
6
6th straight road game
home / road
3rd straight home game

For context, not in our forecast.

Team Comparison

2026 season · box-score averages from 33+ games
KC·SEA
−0.02
rating (0 = average)
+0.07
4.1
runs / game
4.2
4.7
runs allowed / game
4.0
14−19
season record
16−18
9−7
home record
10−9
5−12
away record
6−9
W2
streak
L2
7−3
last 10
6−4
8.0
hits / game
7.7
1.00
home runs / game
1.12
3.5
walks drawn / game
3.9
8.5
batter strikeouts / game
9.1
8.7
pitcher strikeouts / game
8.3
0.27
errors / game
0.41

Rating Trend

KC · SEA · 39 days
Kansas City RoyalsSeattle Mariners
Rating (0 = average team)

Head to Head

last 10 meetings · SEA 5−5
May 2at SEAKC 3 − 2
May 1at SEAKC 7 − 6
Sep 18, 2025at KCSEA 2 − 0
Sep 17, 2025at KCKC 7 − 5
Sep 16, 2025at KCSEA 12 − 5
Jul 3, 2025at SEAKC 3 − 2
Jul 2, 2025at SEASEA 3 − 2
Jul 1, 2025at SEAKC 6 − 3
Jun 30, 2025at SEASEA 6 − 2
Jun 9, 2024at KCSEA 6 − 5

KC · Last 10

7−3 · streak W2
May 2at SEA3 − 2W
May 1at SEA7 − 6W
Apr 30at ATH3 − 6L
Apr 29at ATH2 − 5L
Apr 28at ATH4 − 1W
Apr 26vs LAA11 − 9W
Apr 25vs LAA12 − 1W
Apr 24vs LAA6 − 3W
Apr 22vs BAL6 − 8L
Apr 21vs BAL6 − 5W

SEA · Last 10

6−4 · streak L2
May 2vs KC2 − 3L
May 1vs KC6 − 7L
Apr 29at MIN5 − 3W
Apr 28at MIN7 − 1W
Apr 27at MIN4 − 11L
Apr 26at STL3 − 2W
Apr 25at STL11 − 9W
Apr 24at STL3 − 2W
Apr 22vs ATH5 − 4W
Apr 21vs ATH2 − 5L