Seattle Mariners vs. New York Yankees

Platform comparison

Market context

On 13 August 2026, the Seattle Mariners will travel to face the New York Yankees in a regular-season MLB matchup scheduled for 1:35 PM Eastern Time. A YES share in this market represents a bet on a Mariners victory, whilst a NO share represents a Yankees win. The current crowd-implied probability of 41% for a Mariners win reflects moderate confidence in New York, though the market remains competitive rather than heavily skewed. Settlement occurs on 20 August, allowing several days after the game for official statistics to be confirmed by MLB's governing body.

Historical matchups between these franchises provide context for interpreting the 41% probability. The Yankees hold a significant all-time advantage in head-to-head records, and their recent regular-season performance typically positions them as favourites in most fixtures. However, the Mariners have demonstrated capacity to compete effectively in August, and home-field advantage (if applicable) or recent form shifts can narrow gaps considerably. The current probability suggests traders view the Yankees as slight favourites without dismissing Seattle's chances entirely.

Traders should monitor roster updates through early August, particularly injury reports affecting either team's pitching rotation or key position players. Starting pitcher assignments, typically announced 24–48 hours before game time, often move probabilities noticeably. Weather conditions at the scheduled venue and any last-minute lineup changes could also influence trading activity closer to the 1:35 PM ET start. The market remains open until completion, so postponements would extend the settlement window accordingly.

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.

UK Frequently Asked Questions

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.

Is Polymarket legal in the UK?

Polymarket is accessible to UK traders but is not UKGC-licensed. It operates under US CFTC jurisdiction. UK residents face no domestic legal prohibition on using it, but UKGC consumer protections do not apply. For UKGC-regulated alternatives, Betfair Exchange and Smarkets offer similar prediction-style markets.

Do I pay tax on prediction market profits in the UK?

UKGC-licensed platform profits (Betfair, Smarkets) are typically tax-free gambling winnings for UK individuals. Polymarket profits involve USDC crypto transactions, which HMRC treats as Capital Gains Tax events. Keep full transaction records and report via Self Assessment if gains exceed £3,000 per tax year.

How do I deposit on Polymarket from the UK?

UK traders typically fund Polymarket via Coinbase UK, Kraken or Revolut — buying USDC with GBP and transferring to a Polygon-compatible wallet (MetaMask, Coinbase Wallet). Polymarket's onboarding walks you through the bridging process. Typical GBP-to-USDC conversion costs 0.5–1%.