Mariners vs Yankees Prediction Market Odds, August 12, 2026
| Spread | Total | ML | Best ML | |
|---|---|---|---|---|
▶Mariners | +1.5 63%63% | O 8.5 51%52% | 25%25% | 25% Kalshi |
▶Yankees | -1.5 37%37% | U 8.5 49%48% | 31%33% | 33% Polymarket |
| Spread | Total | Moneyline | Best ML | |
|---|---|---|---|---|
▶Seattle Mariners | +1.5 | O 8.5 | 25% Kalshi | |
▶New York Yankees | -1.5 | U 8.5 | 33% Polymarket |
New York is the 55c favorite for game two at Yankee Stadium and both books agree to the cent, with Kalshi and Polymarket each posting the Yankees at 55c and Seattle at 46c. That is the same price the board carried on August 11, when the Yankees took the opener 4-1, and it is holding despite an injury list that has Aaron Judge, Cody Bellinger and Giancarlo Stanton unavailable. The Yankees are 67-52 and second in the AL East, the Mariners are 56-64 overall and 23-35 on the road, and the moneyline has drawn roughly $21.5K of the board’s $85.2K in cumulative volume.
New York enters Wednesday's second game of the series as the 55c favorite with both books in exact agreement, Kalshi at 55c and Polymarket at 55c, against Seattle at 46c on each platform. That is the same number the board carried on August 11, and the overnight tape barely tested it: the Yankees moneyline opened this window at 53c late Tuesday, sat at 54c for most of the night, and printed 55c by mid-morning. The moneyline has taken roughly $21.5K of the board's $85.2K in cumulative cross-platform volume, with Kalshi carrying about $19.8K of that.
Mariners vs Yankees Market Context
The Yankees are 67-52 and second in the AL East, and the price is holding at 55c despite an injury list that reads like a lineup card. Aaron Judge is on the 60-day injured list with a rib injury and was cleared only for light activity as of August 5. Cody Bellinger is on the 10-day list with a hamstring issue, Giancarlo Stanton on the 10-day list with a calf problem. On the pitching side, Carlos Rodon is on the 15-day list working through rehab starts and Clarke Schmidt is on the 60-day list with an elbow injury. Ben Rice has absorbed the load, leading the team in batting average (.255), home runs (32) and RBIs (75).
Seattle arrives at 56-64 with the sharper split problem. The Mariners are 33-29 at T-Mobile Park and 23-35 on the road, and that road number is the single cleanest explanation for why a 46c price survives a starting-pitcher edge. Their own availability list is long: J.P. Crawford is on the 10-day injured list with left wrist inflammation and is expected to miss roughly two weeks, Luke Raley is out for the season with a left forearm strain, and Josh Naylor was held out of Tuesday's lineup as a day-to-day call. Randy Arozarena leads the club at .276, Julio Rodriguez leads with 18 home runs, and Cole Young leads with 52 RBIs.
The series opener on August 11 went to the Yankees 4-1, and the market did not move off that result. A one-run offensive night from Seattle against a 55c favorite is the outcome the board was already pricing, so there was nothing for the line to correct.
Mariners vs Yankees Pitching Matchup
The starters invert the moneyline. Bryce Miller takes the ball for Seattle at 4-6 with a 3.08 ERA. Will Warren starts for New York at 8-6 with a 4.18 ERA. The market is pricing the team with the worse starter ERA as the favorite by 9c, which is a straightforward read on lineup depth, home field and the Mariners' road form outweighing a 1.10 gap in earned run average.
Miller's strikeout ladder is the most liquid single-player market on the board. His 3-plus strikeout line sits at 84c, 4-plus at 75c, 6-plus at 53c, 7-plus at 36c and 10-plus at 12c. That shape implies a market expectation right around six strikeouts, which is consistent with a starter carrying a sub-3.10 ERA but working for a team that has been pulling arms early.
The run environment is priced modestly for Yankee Stadium. Over 8.5 total runs trades at 51c across both books, Over 9.5 at 40c and Over 7.5 at 59.5c, which centers the implied total near 8.6 runs. The first five innings market has Over 4.5 at 52c, so the books expect a roughly even split of scoring between the opening half and the back half. The run line has New York at minus 1.5 for 37c and Seattle at minus 1.5 for 35c, and a run scored in the first inning trades at 49c.
Cross-platform pricing on this board is unusually tight. The moneyline, the run line, the main total and the first-five total all sit within a cent across Kalshi and Polymarket, with the largest gap on any core line being 2c on the Yankees first-five minus 1.5. Note that the two moneyline sides sum to 101c, which is the standard book margin and not a pricing error. Home run props show slightly more daylight: Cal Raleigh to go deep is 22c on Kalshi and 20c on Polymarket, Julio Rodriguez is 15c and 12c, and Randy Arozarena is 14c and 11c.
When the Mariners vs Yankees Market Resolves
The moneyline resolves to the team that wins the game at Yankee Stadium on August 12, 2026. Run line and total markets settle against the official final score, and first-five-inning markets settle on the score after five completed innings. All of it settles once the game is declared official on both platforms, typically within minutes of the final out.
Key Mariners vs Yankees Catalysts
Warren's command: New York's starter carries a 4.18 ERA and is the reason the favorite price is 55c rather than 60c.
Miller's strikeout total: the 6-plus line at 53c is the cleanest coin-flip market on the board and is the prop most tied to how long Seattle stays in the game.
Yankees lineup availability: Judge, Bellinger and Stanton are all on the injured list, which puts the offense on Ben Rice (32 home runs, 75 RBIs) and the supporting bats.
Seattle road form: 23-35 away from home is the number holding the Mariners under 50c despite the starting-pitcher edge.
Josh Naylor's status: listed day-to-day and out of Tuesday's lineup, and his availability moves Seattle's team total, currently 43c to score more than 4.5 runs.
Book agreement: Kalshi and Polymarket are within a cent on every core line, so there is no cross-platform read here beyond confirmation that both venues see the same game.
Related Mariners vs Yankees Markets
Team-level context lives on the New York Yankees hub and the Seattle Mariners hub, where season-long markets and the rest of each club's schedule are grouped. The full slate of games and futures trades on the MLB prediction markets hub, and every league we cover sits under sports prediction markets.
Resolution Criteria
The moneyline resolves to the team that wins the game between the Seattle Mariners and New York Yankees at Yankee Stadium on August 12, 2026. Each winning team contract pays $1 per share and the losing side resolves to $0. Run line contracts settle against the official final margin, total-runs contracts settle against the official combined final score, and first-five-inning contracts settle on the score after five completed innings. Settlement follows the official MLB box score once the game is declared official, and both Kalshi and Polymarket settle within minutes of that declaration. If the game is postponed, suspended or shortened, each platform applies its own official-game and postponement rules, which generally void or roll the contract to the rescheduled date rather than settling on a partial score.
Key Factors
- Will Warren start for New York (8-6, 4.18 ERA) against a Seattle lineup that scored once in the opener
- Bryce Miller strikeout ladder, with the 6-plus line at 53c and the 4-plus line at 75c
- Yankees injury list: Judge (60-day, rib), Bellinger (10-day, hamstring), Stanton (10-day, calf)
- Seattle road record of 23-35 versus a 33-29 mark at home
- Josh Naylor listed day-to-day and out of Tuesday’s lineup, with Seattle over 4.5 runs at 43c
- Total runs priced near 8.6, with Over 8.5 at 51c on both Kalshi and Polymarket
What are the current Mariners vs Yankees odds?
As of the morning of August 12, 2026, the New York Yankees are the 55c moneyline favorite (55c on Kalshi, 55c on Polymarket) and the Seattle Mariners trade at 46c on both books. That is an implied win probability of about 55% for New York.
Who is favored in Mariners vs Yankees on August 12, 2026?
The Yankees are favored. New York is 67-52 and second in the AL East, Seattle is 56-64 and 23-35 on the road, and the market has held the Yankees at 55c since August 11 with only a 2c dip overnight.
Who are the probable starting pitchers?
Bryce Miller starts for Seattle at 4-6 with a 3.08 ERA and Will Warren starts for New York at 8-6 with a 4.18 ERA. The market favors the team with the higher starter ERA, which reflects lineup depth, home field and Seattle road form.
Where can I trade the Mariners vs Yankees market?
The game trades on both Kalshi and Polymarket. The moneyline alone carries roughly $21.5K of cumulative volume across the two venues, most of it on Kalshi, out of about $85.2K on the full board including run line, totals and player props.
What is the total for Mariners vs Yankees?
Over 8.5 runs trades at 51c on both books as of August 12, 2026, with Over 9.5 at 40c and Over 7.5 at 59.5c, which centers the implied total near 8.6 runs. The first five innings Over 4.5 sits at 52c.
What should I watch before this market resolves?
Watch the Yankees lineup card given that Judge, Bellinger and Stanton are all on the injured list, and watch whether Josh Naylor is active for Seattle after sitting Tuesday. Both are the most likely inputs to move the 55c line before first pitch on August 12, 2026.