San Francisco Giants vs. Miami Marlins

Platform comparison

Active sub-markets

Market context

Polymarket is pricing the Giants-Marlins contract at **93% YES**, so the market is treating a San Francisco win as the clear base case in USDC terms on Polygon, via the usual conditional-token settlement structure. That level implies very little room for a Miami upset, and on a live prediction market it also means late information can matter more than the headline number: a small move in lineup quality, weather, or bullpen availability can shift the price quickly even when the contract already looks heavily one-sided.

Recent baseball pricing has been less uniform than Polymarket’s implied probability. Sportsbooks in the search results sit much closer to a coin-flip-to-lean-Giants range, with one line showing San Francisco around -138 and another around -132, while FanDuel’s research page cites a model lean towards Miami at 56.1% and an 8-run total. That gap is useful context for traders: a 93% market price is far above the broader betting market’s view, so the contract is already assuming either strong Giants confidence or limited willingness to price in upset risk.

For a Polymarket user, the main catalysts are the confirmed starting line-ups, any pitching changes, and whether the game is completed as scheduled, because postponement keeps the market open until the make-up is played, while a cancellation or tie resolves 50-50. The listed game time is 4:10 p.m. ET, and the settlement window runs to 2026-06-27T20:10:00Z, so any rain delay or rescheduling decision can dominate the contract more than pre-game sentiment. ESPN’s game page and the sportsbook feeds are the practical sources to monitor for final status, with the settlement still determined by the official final result rather than market expectations.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track San Francisco Giants vs. Miami Marlins 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

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.

FAQ

Where can I trade this market with the lowest fees?

On Kalshi 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.

Is this market available outside the US?

Kalshi UK 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 Kalshi UK?

Zero. Kalshi UK 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, Kalshi UK triggers a quick verification flow that finishes in minutes.