Cleveland Guardians vs. Houston Astros

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Active sub-markets

Market context

The Cleveland Guardians face the Houston Astros in a 2:10 PM ET MLB clash on 21 June, where the crowd-implied probability for a Guardians win sits at a mere 6%. On Polymarket, this contract trades at 45¢ for the Guardians and 56¢ for the Astros, reflecting a market that heavily favours the Houston side despite the low settlement window expiry of 28 June 2026. The on-chain mechanics utilise USDC on the Polygon network, where conditional tokens lock liquidity until the official final statistics confirm the result.

Historically, such low probabilities for home teams in this fixture are rare but not unprecedented; the Astros have won roughly 60% of their last 10 encounters against the Guardians, a trend that aligns with numberFire’s prediction of a 54.9% win probability for Houston [2][3]. Comparable cases from the 2024 and 2025 seasons show that when a team holds a 60% historical win rate against an opponent, the market often prices the favourite at 55–58¢, mirroring today’s 56¢ quote for the Astros [5].

Traders should monitor the starting pitchers’ performance, specifically Slade Cecconi’s 4.60 ERA for the Astros and Kai-Wei Teng’s new status for the Guardians, as these figures directly influence the over/under of 8.5 points [2][7]. Recent betting trends indicate the Astros are favoured at -131, while the Guardians sit at +120, suggesting a strong market dependency on the pitching matchup [8]. Any announcement regarding player injuries or weather delays before the 2:10 PM ET start will be the primary catalyst for price shifts in the conditional token market.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Cleveland Guardians vs. Houston Astros 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

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.

FAQ

Where can I trade this market with the lowest fees?

On Polymarket 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.

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 Polymarket UK?

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

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.