Seattle Mariners vs. Baltimore Orioles

Platform comparison

Active sub-markets

Market context

The Seattle Mariners travel to Baltimore for a regular-season matchup against the Orioles on 11 June at 7:05 PM ET. The settlement window extends to 18 June, allowing for postponements or rescheduled games within that seven-day buffer. Resolution hinges on official MLB final statistics; cancellations without make-up games or ties trigger a 50-50 split.

A 100% crowd-implied probability on either side of an MLB game is uncommon and warrants scrutiny. Historical precedent suggests such extremes typically reflect either missing information at the time of probability assessment, or a significant disparity in team strength that markets have already priced in. The Orioles finished 2024 as AL East contenders, whilst the Mariners have cycled through competitive and rebuilding phases. Comparing this fixture to similarly lopsided probabilities in prior seasons reveals that crowd confidence often compresses as game day approaches, particularly when injury reports or weather systems emerge within 48 hours of first pitch.

Traders monitoring this market programmatically should flag roster updates, particularly starting pitcher announcements, which typically arrive 24–48 hours before game time. Weather conditions in Baltimore during mid-June rarely force postponements, but humidity and wind patterns can influence scoring. Recent injury bulletins from either organisation—especially to position players or relief arms—should trigger conditional order adjustments. The settlement window's extension to 18 June accommodates makeup games if weather or other factors delay play, a detail relevant for automated monitoring systems that track game status feeds from MLB's official data sources.

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). The odds column is filled only where we have clean data — that avoids the made-up numbers that get a network demoted when search engines cross-check against the source venue.

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 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.

What does it cost to trade on Polymarket App UK?

Zero. Polymarket App 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, 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.