Seattle Mariners vs. Kansas City Royals

Platform comparison

Active sub-markets

Market context

Seattle and Kansas City meet tonight in an MLB game that will settle on the official final result, with no special adjustment for market moves or opinion if the game is completed as scheduled. The crowd price of 52% for Seattle sits close to a coin flip, which fits a series that has already been tight: Kansas City won 3-2 in extra innings on 2 May after Seattle’s Emerson Hancock struck out 14, and the clubs’ recent meetings have tended to stay within one or two runs rather than produce clear separation.

For market reading, the key is that the current price is modest rather than extreme, so late information can matter more than broad season form. Watch for the announced starters, any lineup rest, and weather or delay risk, because postponement keeps the market open until the make-up game is played, while a cancellation would force a 50-50 settlement. ESPN’s recap of the earlier Royals win is the most recent game-level reference point in the search results, and it underlines how closely matched these sides have been in recent head-to-heads.

From a regulatory and access angle, German GlüStV rules can restrict availability for users in Germany, while US CFTC oversight is relevant where event contracts fall within US jurisdictional debate. “No-KYC up to $1,500” generally means small balances or activity can be accessed without full identity verification, but that threshold does not remove local gambling, securities, tax, or platform eligibility rules; it mainly affects onboarding friction for this specific market.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Seattle Mariners vs. Kansas City Royals on the five venues with material liquidity for prediction markets. Live odds come from the Polymarket Polygon order book — the only source that ships real-time data under an open licence. For Kalshi, Betfair and Manifold we list platform attributes (fee, KYC, settlement, payment) instead of fabricated odds, because their APIs use non-comparable contract definitions.

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.

How does resolution work?

Through the UMA Optimistic Oracle on Polygon: a proposer submits the outcome, a two-hour challenge window opens, and USDC payouts settle automatically once the result is final.

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 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.