Arizona Diamondbacks vs. Boston Red Sox

Platform comparison

Market context

The Arizona Diamondbacks and Boston Red Sox met in a game scheduled for 17 August in Boston, and the market’s 1% YES price implies an extreme view that Arizona is very unlikely to win. That is well below the sportsbook range available around the matchup, where Boston was generally a modest home favourite and Arizona traded in the low-to-mid plus-money range, suggesting the prediction market is pricing a far thinner chance than the betting market consensus.

That kind of gap is unusual but not unprecedented in MLB, where crowd prices can overshoot when one side is seen as a clear underdog on the road. Boston’s lineups and notes showed a competitive middle order, while Arizona’s recent injury list included Lourdes Gurriel Jr., Ryan Thompson, Tommy Troy and Zac Gallen among others, which would normally push a team’s win probability down; Boston also had Curtis Mead on the injured list.[1][2] If the game was still pending around settlement, traders would usually watch for late lineup changes, any pitching confirmation, and postponement risk, because this market stays open until a completed game and would revert to 50-50 only for a cancellation or tie.

Recent preview and odds pieces put Boston around -130 to -157 and Arizona around +120 to +133, which is a far more balanced read than a 1% market price.[1][3] That means the key comparison is not whether Arizona is the favourite — it is not — but whether the contract has become detached from even a routine upset chance.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page is a comparison snapshot: one live quote, four reference venues with their key attributes, and a single execution path — every trade button routes to PolyGram, which mirrors the Polymarket order book directly.

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?

Polymarket is geo-blocked in the US/UK/EU. The easiest 0%-fee broker into the same order book is PolyGram. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

Is this market available outside the US?

Polymarket itself is geo-blocked in the US/UK/EU. Always check the legal status of prediction markets in your jurisdiction before trading.

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.

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.