Detroit Tigers vs. Seattle Mariners

Platform comparison

Market context

The Detroit Tigers’ trip to Seattle is priced as a near coin-flip, with the crowd at 47% for **YES**, which is broadly consistent with a market that is treating home advantage and current form as close to balanced. The latest live game page shows Seattle with a far better run prevention profile than Detroit, including a team ERA of 2.62 and WHIP of 0.95 versus Detroit’s 4.32 ERA and 1.44 WHIP, while Detroit has been the more volatile offence by raw scoring output[1].

For historical framing, these teams split recent meetings in a way that supports a market hovering around the middle: Detroit beat Seattle 5-4 on 7 June after also taking a 7-3 game on 5 June, while Seattle had won earlier encounters in that stretch[4][5][6]. That pattern matters for programmable trading because head-to-head edges have been unstable, so a bot or conditional-order workflow should weight starting pitcher confirmation, line movement, and late scratch risk more heavily than the series record itself.

The main catalysts are the pre-game line-up cards, the announced starter pairing, and any weather or schedule delay that could push the contest outside the original settlement window; the listed first pitch is 9:40 p.m. ET, and if the game is postponed it stays open until completion[13]. Recent coverage around the matchup also points to the Mariners’ stronger season-long pitching base and the Tigers’ more compressed recent form, so a trader monitoring API feeds would typically watch for moves tied to the starting rotation, bullpen availability, and any late team news before the market closes[6][14].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). That keeps the comparison honest — a single canonical probability across the row, with the venue-by-venue trade-offs spelt out in the columns next to it.

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?

Polymarket is geo-blocked in the US/UK/EU. The easiest 0%-fee broker into the same order book is Kalshi Fees. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

Is this market available outside the US?

Polymarket itself is geo-blocked in the US/UK/EU. Always check the legal status of prediction markets in your jurisdiction before trading.

What does Polymarket cost to trade?

Polymarket itself charges 0% — the only cost is the Polygon network fee, typically under $0.01 per transaction. Off-chain venues like Kalshi or Betfair charge 2-7% commission.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Kalshi Fees trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.

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.