bayesRatings

Mariners at Royals

MLB · Saturday, May 23 · 3:10 PM CT · Kauffman Stadium · Final SEA 0 – KC 5
← MLB / May 23

Final Box Score

from the game summary
Team123456789THE
SEA000000000041
KC30100100590
Team box
SEA·KC
4
hits
9
0
home runs
0
1
walks
2
2
strikeouts
4
126
pitches thrown
108
1
errors
0
Top hitters
PlayerTeamH-ABRHRRBI
Carter JensenKC1-2102
Luke RaleySEA3-3000
Bobby Witt Jr.KC2-4200
Isaac CollinsKC1-3001
Vinnie PasquantinoKC1-4101
Michael MasseyKC2-4000
Pitchers
PitcherTeamIPHERBBK
George Kirby (L)SEA6.09303
Stephen Kolek (W)KC9.04012

For context, not in our forecast.

Game Flow

score margin
KC +5
SEA +5
123456789
largest lead: KC 5 · SEA 0lead changes: 0

For context, not in our forecast.

Final · our forecast was SEA 51%, KC 49% · Updated May 23

Expected margin
Even
Expected score
SEA 4.0 – 3.8 KC
Expected total
7.8
MarinersThe matchupRoyals
−106Our fair odds+106
4.0Expected runs3.8
+0.06Power rating−0.07
4.1Runs / game3.8
3.8Allowed / game4.4
7.4Hits / game7.8
1.13Home runs / game0.94
3.8Walks drawn / game3.4
25−27Season record20−31
5−5Last 101−9

Prediction markets

Kalshi · Polymarket US · ProphetX · Novig
SEA chance · KC chance
Our model fair51.4%48.5%
Kalshi55.7%49.7%
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
SEASeattle Mariners−10651%−12655.7%———
KCKansas City Royals+10649%+10149.7%———
Spreadabout even
SEASeattle Mariners−0.3our margin————
KCKansas City Royals+0.3our margin————
Totalwe expect 7.8
Over7.8our total————
Under7.8our 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

Even game expected
Seattle Mariners by 12 runs: <1%Seattle Mariners by 11 runs: <1%Seattle Mariners by 10 runs: 1%Seattle Mariners by 9 runs: 1%Seattle Mariners by 8 runs: 1%Seattle Mariners by 7 runs: 2%Seattle Mariners by 6 runs: 3%Seattle Mariners by 5 runs: 4%Seattle Mariners by 4 runs: 6%Seattle Mariners by 3 runs: 8%Seattle Mariners by 2 runs: 11%Seattle Mariners by 1 run: 14%Kansas City Royals by 1 run: 17%Kansas City Royals by 2 runs: 10%Kansas City Royals by 3 runs: 7%Kansas City Royals by 4 runs: 5%Kansas City Royals by 5 runs: 3%Kansas City Royals by 6 runs: 2%Kansas City Royals by 7 runs: 2%Kansas City Royals by 8 runs: 1%Kansas City Royals by 9 runs: 1%Kansas City Royals by 10 runs: <1%Kansas City Royals by 11 runs: <1%Kansas City Royals by 12 runs: <1%
← SEA wins byKC wins by →
Seattle Mariners wins by 2 or more38%
Seattle Mariners wins by 3 or more27%
Kansas City Royals wins by 2 or more32%
Decided by one run31%

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

7.8 expected
1 runs: 3%2 runs: 2%3 runs: 9%4 runs: 6%5 runs: 13%6 runs: 8%7 runs: 13%8 runs: 8%9 runs: 10%10 runs: 6%11 runs: 7%12 runs: 4%13 runs: 4%14 runs: 2%15 runs: 2%16 runs: 1%17 runs: 1%18 runs: 1%19 runs: <1%20 runs: <1%21 runs: <1%
Total runs, both teams
Total over 5.568%
Total over 7.547%
Total over 9.529%
Total from 6 to 939%

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
SEAGeorge Kirby SP · last 3 starts: 17.2 IP, 4.58 ERA, 18 Kstarted
KCStephen Kolek SP · last 3 starts: 17.0 IP, 4.24 ERA, 12 Kstarted

Starting pitchers are part of our forecast.

Rest and Schedule

before this game
SEA·KC
May 22 at KC
last game
May 22 vs SEA
0 days
days of rest
0 days
6
games in last 7 days
6
2nd straight road game
home / road
5th straight home game

For context, not in our forecast.

Team Comparison

2026 season · box-score averages from 51+ games
SEA·KC
+0.06
rating (0 = average)
−0.07
4.1
runs / game
3.8
3.8
runs allowed / game
4.4
25−27
season record
20−31
14−15
home record
13−14
11−12
away record
7−17
W2
streak
L4
5−5
last 10
1−9
7.4
hits / game
7.8
1.13
home runs / game
0.94
3.8
walks drawn / game
3.4
9.0
batter strikeouts / game
8.2
8.7
pitcher strikeouts / game
8.4
0.37
errors / game
0.37

Rating Trend

SEA · KC · 59 days
Seattle MarinersKansas City Royals
Rating (0 = average team)

Head to Head

last 10 meetings · KC 6−4
May 22at KCSEA 2 − 0
May 3at SEAKC 4 − 1
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

SEA · Last 10

5−5 · streak W2
May 22at KC2 − 0W
May 20vs CHW5 − 4W
May 19vs CHW1 − 2L
May 18vs CHW6 − 1W
May 17vs SD3 − 8L
May 16vs SD4 − 7L
May 15vs SD0 − 2L
May 14at HOU8 − 3W
May 13at HOU3 − 4L
May 12at HOU10 − 2W

KC · Last 10

1−9 · streak L4
May 22vs SEA0 − 2L
May 20vs BOS3 − 4L
May 19vs BOS1 − 7L
May 18vs BOS1 − 3L
May 17at STL2 − 0W
May 16at STL2 − 4L
May 15at STL4 − 5L
May 14at CHW2 − 6L
May 13at CHW5 − 6L
May 12at CHW5 − 6L