Baltimore Orioles vs. Boston Red Sox

Platform comparison

Market context

The Baltimore Orioles travel to Boston for a regular-season matchup against the Red Sox on 2 June at 18:45 ET, with the settlement window extending to 9 June to accommodate potential postponements. The 100% implied probability suggests either a data error in the crowd assessment or that traders are treating this as a certainty event, which warrants scrutiny given MLB's inherent match variance and weather exposure in early June.

Historical precedent indicates that single-game MLB markets rarely sustain 100% probabilities unless one team is substantially depleted or the event has already occurred. The Orioles and Red Sox occupy different competitive positions within the AL East, with recent seasons showing neither club as a prohibitive favourite in head-to-head fixtures. For algorithmic traders, this extreme probability distribution presents a potential arbitrage signal—either the market has misprice the event or external information (roster changes, injury announcements) has not yet propagated through the platform.

Key variables to monitor programmatically include starting pitcher assignments, which typically finalise 24–48 hours before game time, and weather forecasts for Fenway Park, where June conditions can shift rapidly. Any roster moves, particularly involving either team's primary rotation, would materially affect win probability models. Traders employing conditional orders should flag the postponement clause: if weather forces a delay beyond the settlement window's closure, the market remains open, creating duration risk that standard pricing models may not capture. MLB's official box score serves as the definitive resolution source.

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

Resolution source: This market settles from the official publication at https://www.mlb.com/. A proposer submits the result to the UMA Optimistic Oracle on Polygon, the two-hour challenge window opens, and the smart contract pays out in USDC.

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?

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.

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.