San Francisco Giants vs. San Diego Padres

Platform comparison

Market context

The game is a one-off MLB meeting between two NL West rivals, and the current **46% YES** price on San Francisco is close to a coin flip, which fits a matchup where recent results have swung both ways. In the most recent game before this one, San Diego beat San Francisco 6-5 on 1 August, while the head-to-head sample since last season has included both Giants wins and Padres wins rather than a stable edge for either side[2][1][9].

For a trader running this programmatically, the main input is not the market price itself but the live state feed: confirmed starters, late scratches, lineup release, and whether the game is completed as scheduled. Recent series data show San Diego has been the stronger short-run side overall, going 7-3 over its last 10 with a 3.48 ERA, while San Francisco was 5-5 with a 4.29 ERA, but those form lines still leave plenty of single-game variance[5]. The primary catalyst is the official game result; if the game is postponed, the market stays open until completion, and only a cancellation or tie triggers a 50-50 settlement, so any automation should watch for MLB status changes as well as the final box score[11].

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

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

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 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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Polymarket Bot UK trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.

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.