San Francisco Giants vs. Miami Marlins

Platform comparison

Active sub-markets

Market context

The San Francisco Giants are at Miami in the second game of the series, and the market’s **71%** crowd-implied chance on San Francisco still leaves a meaningful upset path if the home side’s pitching edge holds. The game is scheduled to start at 4:10pm ET, and this contract settles directly on the official final result, with a postponed game staying open until completion and a cancelled game or tie resolving 50-50.

The probability sits closer to a strong favourite than a coin-flip, which is consistent with pre-game pricing that has already leaned towards Miami at home in some betting markets, while projection models have remained fairly tight. One listed preview had Miami around -140 on the moneyline, but another match-up forecast still produced only a narrow edge either way, which is the sort of split that can make a 71% crowd price look aggressive if late line movement turns against the Giants.[1][3] For prediction markets, that kind of gap often reflects not just baseball form but the mechanics of on-chain settlement: a USDC-denominated position can reprice quickly if the public money follows the sportsbook move rather than the model consensus.

Traders should watch for any late lineup, pitching, or weather updates, because MLB games can move sharply when a starter is scratched or a delay changes bullpen usage. MLB’s game preview highlighted Trevor McDonald’s recent run of limiting damage and Max Meyer’s unbeaten stretch, so any change to those pitching assumptions would matter more than the calendar date alone.[5] If the game is completed on schedule, the market should resolve cleanly off the final box score; if not, the settlement window extends until the make-up is played.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

Methodologically this overview focuses on on-chain pricing: Polymarket's live mid comes from the Polygon conditional-token order book and settles automatically in USDC. The other three venues — Kalshi, Betfair, Manifold — are listed with their platform attributes, because they operate off-chain and a 1:1 comparison of contract mechanics isn't possible.

Resolution & payout

Settlement is on-chain via UMA Optimistic Oracle. A proposer posts the outcome with a bond, a two-hour dispute window opens, then the smart contract lifts winning conditional tokens to 1 USDC and sends payments to holders' wallets automatically. No withdrawal fees beyond Polygon gas.

Off-chain venues (Kalshi, Betfair, Smarkets) settle in local fiat through bank-side clearing — faster than SWIFT, slower than on-chain. Manifold pays no real cash.

FAQ

Where can I trade this market with the lowest fees?

On BTC Prediction, 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?

BTC Prediction 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'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 BTC Prediction?

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