Seattle Mariners vs. Kansas City Royals

Platform comparison

Active sub-markets

Market context

The Seattle Mariners travel to Kansas City on 24 May for a regular-season matchup against the Royals, with first pitch scheduled for 2:10pm ET. The current 1% implied probability for a Mariners victory reflects substantial confidence in Kansas City, though the settlement window extends to 31 May to accommodate any postponements.

Historical matchups between these franchises offer limited predictive power for single-game outcomes, but the Royals have maintained a stronger record against AL West opponents in recent seasons. The Mariners' inconsistency—particularly in road performances—has been a defining characteristic of their recent campaigns, whilst Kansas City has shown improved stability under their current management structure. Single-game probabilities of 1% typically emerge when one team faces significant structural disadvantages: missing key rotation arms, depleted bullpen depth, or a pronounced home-field advantage for the opponent.

Traders should monitor lineup confirmations released 24 hours before first pitch, particularly any late-notice absences from either side's batting order or pitching staff. The Mariners' injury status heading into late May will prove decisive; any absence of core offensive contributors would reinforce the market's current lean. Weather conditions at Kauffman Stadium merit attention, as wind direction and temperature can meaningfully affect ball carry in Kansas City's elevation. Recent form across the preceding week—win-loss streaks, run differential, and bullpen usage patterns—will provide the most granular signal for recalibration closer to game time.

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

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

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'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.

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.