Seattle Mariners vs. Washington Nationals

Platform comparison

Active sub-markets

Market context

The Seattle Mariners travel to Washington for a day game against the Nationals on 13 June at 4:05 PM ET. Polymarket currently prices a Mariners victory at 22 per cent, implying roughly 78 per cent probability for a Washington win. This pricing reflects the Nationals' home-field advantage and recent form, though the settlement window extends to 20 June to accommodate any postponements.

Historical matchups between these franchises show competitive balance over recent seasons, with neither team establishing decisive dominance in head-to-head records. The Mariners have periodically fielded competitive rosters but have struggled with consistency, whilst the Nationals, despite their 2019 World Series championship pedigree, have cycled through rebuilding phases. When evaluating the 22 per cent odds, traders should consider that day games favour teams with stronger bullpen depth and fewer travel fatigue factors—the Nationals' home status partially offsets any scheduling disadvantage the Mariners might face.

Key variables for traders include starting pitcher matchups, which typically drive significant probability shifts in baseball markets, and any roster updates announced in the days before 13 June. Recent injury reports or roster moves could shift the implied probability materially. The Nationals' recent performance trajectory and the Mariners' offensive output against left-handed pitching merit close monitoring. Settlement hinges on official MLB final statistics; any postponement triggers market extension rather than early resolution, so traders should track weather forecasts for the Washington DC area during the scheduled window.

Methodology

This page reviews Seattle Mariners vs. Washington Nationals across five venues. We show live odds for Polymarket-based markets (sourced from the Polygon order book); for other venues we list platform attributes, since the comparable contracts are not exposed via a public API on every venue. Every CTA points at Polymarket UK — the application we operate, where you trade directly against the Polymarket order book at 0% fees.

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?

Polymarket 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 Polymarket UK?

Zero. Polymarket 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 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.