Miami Marlins vs. Houston Astros

Platform comparison

Market context

The Houston Astros defeated the Miami Marlins 8–5 in their July 20 MLB clash at Daikin Park, snapping a four-game losing streak with Jeremy Peña hitting a grand slam and Yordan Álvarez scoring twice [1][3]. Since the game has already concluded, the prediction market titled “Miami Marlins vs. Houston Astros” will resolve definitively to “Houston Astros,” rendering the current 0% YES crowd-implied probability for the Marlins accurate and final [1].

Historically, Polymarket contracts on completed MLB games settle within minutes of the official final statistics being published by MLB, with USDC payouts executed automatically on Polygon via conditional tokens once the resolution source confirms the winner [1]. In comparable cases where a game ends before the settlement window closes, traders observe no volatility post-result; the price locks at 100% for the winning side, and open positions close immediately without further on-chain activity.

Traders should monitor the official MLB final stats page for any late adjustments, though no such changes are expected given the AP and ESPN recaps both confirm the 8–5 outcome [1][3]. With the settlement window ending on 2026-07-28, the contract will resolve shortly after verification, and no further catalysts—such as pitcher announcements or schedule shifts—apply, as the event is complete [2][4].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). That keeps the comparison honest — a single canonical probability across the row, with the venue-by-venue trade-offs spelt out in the columns next to it.

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

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.

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 Polymarket cost to trade?

Polymarket itself charges 0% — the only cost is the Polygon network fee, typically under $0.01 per transaction. Off-chain venues like Kalshi or Betfair charge 2-7% commission.

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 PolyGram trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.