Seattle Mariners vs. New York Yankees

Platform comparison

Market context

The Seattle Mariners travel to face the New York Yankees on 11 August at 7:05 PM ET in a regular-season matchup. The 46% implied probability for a Mariners victory sits notably below the typical sportsbook consensus, where the Yankees have been favoured at around −130 to −140 moneyline odds (equivalent to roughly 57% implied probability). This 11-percentage-point divergence between prediction-market pricing and conventional sportsbook lines suggests either undervaluation of Seattle's chances or overconfidence in New York's recent form among traditional bookmakers.

Historical context matters here: the Yankees have maintained a stronger win percentage against AL West opponents over the past three seasons, though the Mariners' pitching depth has proven competitive in head-to-head matchups. The Yankees' record in August games since 2022 shows marginal regression compared to their season averages, a pattern worth monitoring given the late-summer timing. Conversely, Seattle has historically performed better in road games against East Coast teams when their rotation is fully healthy.

Traders should monitor roster announcements through 10 August, particularly regarding starting pitcher assignments and any late injury updates. The Yankees' bullpen usage patterns in their preceding games will signal fatigue levels heading into this fixture. Weather conditions at Yankee Stadium—notably humidity and wind direction affecting fly-ball distance—carry material significance given both teams' recent offensive tendencies. Recent form divergence, with New York's last five games and Seattle's corresponding stretch, will likely compress the current probability gap as game day approaches.

Methodology

We track Seattle Mariners vs. New York Yankees across the five venues with material prediction-market liquidity. The probability shown is the live Polymarket mid; the comparison rows summarise how each venue treats the underlying contract — fees, KYC thresholds, settlement currency, deposit options. The highlighted row marks the cheapest route into Polymarket's order book.

Resolution & payout

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

FAQ

Is this market available outside the US?

Polymarket itself is geo-blocked in the US/UK/EU. Always check the legal status of prediction markets in your jurisdiction before trading.

How does resolution work?

Through the UMA Optimistic Oracle on Polygon: a proposer submits the outcome, a two-hour challenge window opens, and USDC payouts settle automatically once the result is final.

What's the difference between YES and NO shares?

A YES share pays $1.00 if the event happens, $0 otherwise. A NO share pays $1.00 if the event doesn't happen. The market price between 0¢ and 100¢ is the implied probability.

What does Polymarket cost to trade?

Polymarket itself charges 0% — the only cost is the Polygon network fee, typically under $0.01 per transaction. Off-chain venues like Kalshi or Betfair charge 2-7% commission.

How reliable are the quoted odds?

The YES/NO percentages are the live mid-prices of the Polymarket order book. On deep markets they move every few seconds; on thinner ones you'll see short plateaus.