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 1:40PM ET in a regular-season MLB matchup. The current crowd-implied probability of 46% for a Red Sox victory reflects moderate confidence in Cleveland, though the market remains competitive. Settlement occurs on 7 June, providing a six-day window after the scheduled game date to account for potential postponements.

Historical context matters here: the Red Sox and Guardians have traded division dominance over the past decade, with Cleveland's recent competitive strength (2022–2023 AL Central titles) offsetting Boston's longer track record of postseason appearances. When examining comparable single-game markets between these franchises, the probability typically clusters between 45–55% depending on pitching matchups and injury status. A 46% YES reading suggests the market is pricing in slight Guardians favouritism, likely driven by roster composition or recent form rather than a decisive edge.

Traders should monitor starting pitcher announcements—typically confirmed 24–48 hours before game time—as this remains the single largest catalyst for repricing in baseball markets. Recent injury reports from both organisations' official channels will affect bullpen depth assumptions. Weather conditions at the venue and any last-minute roster moves (call-ups, trades, or IL placements) can shift probabilities materially. For programmatic approaches, integrating MLB's official schedule API alongside real-time injury databases allows conditional order placement around these catalysts. The six-day settlement window provides adequate time for data reconciliation, though traders should note that postponements trigger market extension rather than early resolution.

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 App UK, which mirrors the Polymarket order book directly.

Resolution & payout

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

FAQ

Where can I trade this market with the lowest fees?

On Polymarket App UK, 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.

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.

Do I need to KYC for this market?

Not under $1,500 of lifetime trading volume. Above that threshold, Polymarket App UK triggers a quick verification flow that finishes in 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.