Seattle Mariners vs. Washington Nationals

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Active sub-markets

Market context

On 13 June 2026, the Seattle Mariners will travel to Washington to face the Nationals in a regular-season MLB fixture. In prediction markets, a YES share represents a bet on the Mariners winning; a NO share bets on the Nationals. The current 0% probability assigned to YES indicates traders are pricing the Nationals as near-certain favourites, though this extreme reading warrants scrutiny given the inherent uncertainty in single-game outcomes.

The Mariners and Nationals occupy different competitive positions in their respective divisions. Seattle typically contends in the AL West, whilst Washington operates in the NL East. Historical matchups between these teams show competitive balance, with neither club holding a decisive edge in head-to-head records. A 0% probability for either team in an MLB game is unusual and often reflects thin liquidity or early-market positioning rather than genuine certainty. Even heavily favoured teams in baseball lose roughly 35–45% of their games, making extreme probabilities rare in well-informed markets.

Traders should monitor pitching assignments, injury reports, and recent form in the days preceding the match. The Nationals' roster composition and bullpen depth relative to Seattle's will influence fair odds. Weather conditions at the venue—temperature and wind patterns—can materially affect play, particularly for teams with distinct offensive profiles. Official MLB injury updates and any roster moves announced before 13 June will provide concrete data for reassessing the current pricing. The settlement window extends to 20 June, allowing time for postponements or make-up games if weather intervenes.

Methodology

We track Seattle Mariners vs. Washington Nationals on the five venues with material liquidity for prediction markets. Live odds come from the Polymarket Polygon order book — the only source that ships real-time data under an open licence. For Kalshi, Betfair and Manifold we list platform attributes (fee, KYC, settlement, payment) instead of fabricated odds, because their APIs use non-comparable contract definitions.

Resolution & payout

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.

FAQ

Where can I trade this market with the lowest fees?

On Prediction Market UK, which mirrors the Polymarket order book at 0% fees. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

Is this market available outside the US?

Prediction Market UK is available in most jurisdictions where Polymarket isn't directly accessible. Polymarket itself is geo-blocked in the US/UK/EU. Always check local regulations.

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.

How fast are USDC deposits?

Polygon credits deposits after 12 confirmations — usually under 30 seconds. Withdrawals follow the same path and land back in your wallet within minutes.