Seattle Mariners vs. Cleveland Guardians

Platform comparison

Market context

The real-world event is an MLB game between the Seattle Mariners and Cleveland Guardians at Progressive Field in Cleveland, scheduled for 1:40pm ET on 28 June 2026. The Guardians won the previous two matchups in this series, including a 6-5 victory on 28 June and a 4-3 win on 27 June, with Rhys Hoskins delivering a key two-run double in the eighth inning of the latest contest[1][3]. This pattern of consecutive Guardians wins frames the current 0% crowd-implied probability for a Mariners victory as a reflection of recent form rather than an arbitrary outlier, mirroring how conditional order bots historically adjust positions after two straight losses by the same team.

A power-user approaching this programmatically would monitor starting pitcher Emerson Hancock, who holds a 1.47 ERA in three career starts against the Guardians, and Gavin Williams, who maintains a 2.64 ERA and .210 opponents’ average in seven home starts this year[5]. Traders should also watch for any late-injury announcements or weather dependencies, as Progressive Field has hosted several rain-delayed games in June 2026, and the game is part of a “Kids Fun Day” event that may influence attendance and pitch usage[2]. Recent box score data confirms the Guardians’ offensive consistency, with their eighth-inning rallies proving decisive in both recent games[1].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Seattle Mariners vs. Cleveland Guardians 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

Settlement runs on-chain. Polymarket's contract logic separates YES and NO shares as conditional tokens; at resolution the winning share lifts to $1.00 and the losing one to $0. The outcome input comes from the UMA Optimistic Oracle, which secures against bad resolution with a bond + dispute window.

Once finalised, the smart contract pays USDC to the holders' wallets within minutes — no withdrawal fees beyond Polygon network gas. Kalshi settles in USD via CFTC clearance, Betfair in account currency net of commission, Manifold in play-money mana with no cash-out.

FAQ

Where can I trade this market with the lowest fees?

Polymarket is geo-blocked in the US/UK/EU. The easiest 0%-fee broker into the same order book is Polymarket App UK. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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 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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Polymarket App UK trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.

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.