San Francisco Giants vs. Miami Marlins

Platform comparison

Active sub-markets

Market context

Polymarket is pricing the Giants–Marlins moneyline at about **97% YES** for the Giants contract, even though the broader sportsbook market around the same matchup has leaned the other way, with Miami carrying the favourite tag in several pre-game previews. On Polymarket, the position is settled in USDC on Polygon through conditional tokens, so the key question is simply which club is awarded the official win; postponement keeps the market open, while a cancellation or tie would force a 50-50 outcome under the rules.

That 97% level is very high for a single MLB game and usually reflects either a late information edge, a stale opposing side, or thin liquidity rather than certainty about the result itself. Comparable late-stage baseball markets often move sharply once line-ups are confirmed, because one pitcher change, rest day, or weather delay can materially shift the expected win rate. The recent external pricing is less supportive of such an extreme Giants probability: one preview had Miami at 56.1% to win, while another listed the Marlins around -149 on the moneyline, which still implies a much closer game than Polymarket’s current view.[1][4]

For traders, the main catalysts are the official line-ups, any late pitching confirmation, and whether the game starts on time or is pushed by weather, because postponement changes the contract timing but not the underlying matchup. The game is listed for 4:10 p.m. ET, and Polymarket’s market page shows substantial turnover already, suggesting participants are reacting to live information rather than just season records.[2][6] With the settlement window running to 2026-06-27T20:10:00Z, any delay or make-up scheduling will matter more to timing than to direction, unless the game is voided under the market rules.

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

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?

On Polymarket Legit?, 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?

Polymarket Legit? 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.

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.