Boston Red Sox vs. Seattle Mariners

Platform comparison

Active sub-markets

Market context

On 20 June 2026, the Boston Red Sox faced the Seattle Mariners in a Major League Baseball game at T-Mobile Park, with the Red Sox winning 5–1. This outcome settled a prediction market where a "YES" share on "Boston Red Sox" represented a bet that the Red Sox would win the game, while a "NO" share indicated the opposite. The market currently shows a 100% implied probability for "YES", reflecting the game’s completed status and the confirmed result.

Historically, markets with 100% implied probability after a game’s conclusion are common, as the outcome is no longer uncertain. Comparable cases include any MLB game where the final score is officially recorded, such as the Red Sox’s 5–1 victory over the Mariners, which left no room for doubt. Traders should note that such probabilities typically emerge post-settlement, not before, and serve as a confirmation rather than a forecast.

Key catalysts for traders include official MLB announcements on game postponements or cancellations, though this game has already been completed. Recent news from the Mariners confirmed a schedule change for a doubleheader, moving Game 1 to 19 June, but this did not affect the 20 June matchup[5]. With the settlement window ending on 28 June 2026, no further action is required, as the result is final and the market will resolve to "Boston Red Sox".

Sources: 1 · 2 · 3 · 4 · 5

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 Prediction Market UK, 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

Is this market available outside the US?

Prediction Market UK is available in most jurisdictions where Polymarket isn't directly accessible. Polymarket itself is geo-blocked in the US/UK/EU. Always check local regulations.

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 it cost to trade on Prediction Market UK?

Zero. Prediction Market UK routes every order to the live Polymarket order book; the only cost is the Polygon network fee, typically under $0.01 per transaction.

Do I need to KYC for this market?

Not under $1,500 of lifetime trading volume. Above that threshold, Prediction Market 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.