Seattle Mariners vs. Kansas City Royals

Platform comparison

Active sub-markets

Market context

Seattle and Kansas City meet in a single-game MLB market priced close to a coin flip, with the crowd currently at 51% on Seattle. That sits against a recent head-to-head that has been tight enough to keep either side live late: the Royals beat the Mariners 3-2 in Seattle on 2 May, and the clubs have generally played low-margin games over the last stretch. When the market is this near even, small edges around starting pitching, bullpen freshness and line-up composition tend to matter more than broad season records.

For traders, the main catalysts are the starting pitcher confirmations, any late rest for regulars, and whether either club is carrying over bullpen stress from the previous series. Seattle’s recent numbers against left-handed starters have been cited as a weak point in preview work, while Kansas City’s offence has been running below four runs a game, which supports another close, low-scoring script if the game stays with the first-choice pitchers. The most useful late signal will be the official line-ups and any beat reporting on scratches or platoon changes; if a key bat sits, the fair price can move quickly in a one-run game.

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 PolyGram, which mirrors the Polymarket order book directly.

Resolution & payout

Settlement runs on-chain. Polymarket's contract logic separates YES and NO shares as conditional tokens; at resolution the winning share lifts to $1.00 and the losing one to $0. The outcome input comes from the UMA Optimistic Oracle, which secures against bad resolution with a bond + dispute window.

Once finalised, the smart contract pays USDC to the holders' wallets within minutes — no withdrawal fees beyond Polygon network gas. Kalshi settles in USD via CFTC clearance, Betfair in account currency net of commission, Manifold in play-money mana with no cash-out.

FAQ

Where can I trade this market with the lowest fees?

On PolyGram, 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.

Is this market available outside the US?

PolyGram 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 does it cost to trade on PolyGram?

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

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.