Boston Red Sox vs. Cleveland Guardians

Platform comparison

Active sub-markets

Market context

The Boston Red Sox face the Cleveland Guardians on 31 May at 1:40 PM ET in an AL East matchup. Polymarket currently prices the Red Sox win at 47%, implying roughly even odds between the two clubs. This contract settles on official MLB final statistics; if postponement occurs, the market remains open until completion. Cancellation without a make-up game or a tie would trigger a 50-50 split resolution.

Historical context suggests the 47% probability reflects genuine competitive balance. Since 2020, the Red Sox hold a slight edge in head-to-head records against Cleveland, though both franchises have experienced significant roster turnover. The Guardians' 2023 AL Central dominance and subsequent seasons demonstrate they remain capable opponents, whilst Boston's recent performance has been inconsistent enough to prevent the market from pricing them as clear favourites despite playing at home.

Traders should monitor starting pitcher assignments and injury reports through the settlement window closing 7 June. Bullpen availability—particularly for Cleveland, which has relied heavily on relief depth—can shift late-market sentiment. Weather conditions at Fenway Park on game day may favour either team's style; the Red Sox typically benefit from wind patterns that reduce fly-ball distance. Any roster moves or roster-related announcements from either club in the days preceding the match could trigger repricing, as could updated Vegas lines from major sportsbooks, which often precede Polymarket adjustments by several hours.

Methodology

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

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

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.

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 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.