Seattle Mariners vs. Cleveland Guardians

Platform comparison

Active sub-markets

Market context

The Seattle Mariners defeated the Cleveland Guardians 3-1 in their MLB game on Friday, 26 June 2026 at Progressive Field, with Colt Emerson’s seventh-inning homer and J.P. Crawford’s go-ahead single sealing the win[1][2]. This result directly validates the market’s current 100% YES probability for the Mariners, as the game has already concluded and the outcome is official.

Historically, markets showing 100% implied probability for a team that has already won are rare but unambiguous; similar cases in 2024–2025 saw no settlement disputes once final MLB statistics were published[1]. Platforms diverge here: Polymarket uses decimal odds and no KYC, while Kalshi and Betfair require identity verification and quote implied probabilities, often leading to slower price adjustments post-result. Fee structures also vary—Polymarket charges 0% on wins, whereas Kalshi applies up to 5% on settled trades.

Traders should monitor any official MLB announcements regarding game postponements or cancellations, though none apply here since the match is complete[3]. Recent coverage from ESPN confirms the final score and player stats, eliminating ambiguity[1]. For comparison, Smarkets and Betfair may delay resolution if secondary sources conflict, but Polymarket resolves instantly on primary MLB data. Always verify the settlement window end time (2026-07-03T23:10:00Z) to ensure no late appeals alter the outcome.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page compares Seattle Mariners vs. Cleveland Guardians 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

Where can I trade this market with the lowest fees?

On PolyGram, 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?

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 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.