Arizona Diamondbacks vs. Boston Red Sox

Platform comparison

Market context

Boston’s home game with Arizona is trading at just 1% YES, which implies the market is treating a Red Sox win as overwhelmingly the base case. On Polymarket, that contract settles through USDC on Polygon via conditional tokens, so the price reflects the crowd’s view of who will be credited with the official result rather than the scoreline in isolation.

That is a very compressed number for two teams that entered the matchup with similar records: Boston at 66-58 and Arizona at 66-59, with Fenway Park listed as the venue and the scheduled first pitch at 7:10 pm ET.[1][2] Comparable low-single-digit prices in MLB usually appear when one side has a marked pitching, home-field or lineup edge, rather than a broad gap in season standings. In this case, market participants are likely anchoring on Boston’s home setting and the pre-game matchup assumptions, while keeping in mind that a late swing in a one-run game can still flip the token outcome.

Traders should watch for three practical catalysts: confirmed line-ups, any pitching change, and any delay or postponement notice, because the market remains open if the game is merely moved and only resolves 50-50 if it is cancelled outright or ends tied.[2] The game was still listed in live coverage on ESPN on 18 August, and ESPN’s game page showed it as being played at Fenway Park with weather and live status updates attached, which is the sort of source that can quickly alter how a conditional-token market is priced intraday.[1]

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

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

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.

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.

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.