Seattle Mariners vs. Athletics

Platform comparison

Active sub-markets

Market context

The Seattle Mariners face the Oakland Athletics on 25 May at 9:40 PM ET in a regular-season MLB matchup. The 52% crowd-implied probability favouring Seattle reflects the Mariners' stronger 2024 roster composition and recent performance trajectory, though the Athletics remain competitive within their division context. Across platforms, this probability translates differently: Polymarket displays it as a decimal of approximately 1.92 for a Seattle win, whilst Kalshi and Betfair present the same underlying probability through their respective odds formats, with Kalshi's binary structure and Betfair's fractional odds creating distinct visual representations for the same market event.

Historical matchups between these franchises show Seattle has maintained a slight edge in head-to-head records over recent seasons, though Oakland's unpredictability—particularly in May fixtures—has occasionally produced upset results that shift market pricing mid-series. The current 52% reading suggests modest confidence rather than conviction, consistent with how these platforms price games between teams of unequal strength but without dominant form indicators.

Traders should monitor pitching assignments, which typically confirm 24 hours before game time and materially shift probabilities on all platforms. Injury reports for key position players, particularly Seattle's outfield depth, could trigger repricing across Polymarket, Kalshi, and Betfair simultaneously. Weather conditions at the Oakland Coliseum—wind direction and temperature—historically favour certain playing styles and occasionally prompt line movement. Fee structures vary between platforms (Kalshi charges no trading fees, whilst Polymarket and Betfair apply percentage-based commissions), affecting the effective probability thresholds at which arbitrage becomes viable.

Methodology

This page compares Seattle Mariners vs. Athletics specifically across Polymarket, Kalshi, Betfair Exchange and Smarkets. Live odds come from the Polymarket order book; the other venues' contract details are maintained manually because their APIs aren't directly comparable. Every CTA routes to PolyGram, which mirrors the Polymarket order book at 0% fees.

Resolution & payout

Settlement is the biggest difference between the four platforms: Polymarket on-chain in USDC (instant), Kalshi USD via CFTC (T+1), Betfair and Smarkets in local currency via bank withdrawal (T+1 to T+3). PolyGram routes every trade directly into Polymarket's on-chain settlement, which is why payouts land fastest.

FAQ

Is this market available outside the US?

PolyGram 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.

What does it cost to trade on PolyGram?

Zero. PolyGram routes every order to the live Polymarket order book; the only cost is the Polygon network fee, typically under $0.01 per transaction.

Do I need to KYC for this market?

Not under $1,500 of lifetime trading volume. Above that threshold, PolyGram triggers a quick verification flow that finishes in minutes.