Detroit Tigers vs. Houston Astros

Platform comparison

Active sub-markets

Market context

The Detroit Tigers face the Houston Astros on 15 June at 8:10PM ET in a regular-season MLB matchup. The current 74% implied probability favours Detroit, reflecting the Tigers' stronger recent form and home-field advantage at Comerica Park. Across major prediction platforms, this market shows notable structural differences: Polymarket displays the probability directly at 74%, whilst Kalshi and Betfair would express equivalent positions as decimal odds (approximately 3.85 and 3.8 respectively), creating friction for traders comparing across venues. Fee structures diverge significantly—Kalshi charges 2% on both sides of resolved contracts, Betfair takes commission only on net winnings, and Polymarket applies a 2% fee on withdrawals, meaningfully affecting expected returns on a market this tight.

Historical context matters here: the Tigers have won 11 of their last 16 games as of early June, whilst Houston's record sits at 32–31, suggesting the probability gap reflects genuine form differential rather than noise. The Astros' pitching depth remains a wildcard—if they deploy a top-tier starter, the odds could compress considerably. Traders should monitor roster announcements 24–48 hours before first pitch, particularly injury updates to either team's rotation or key position players. Weather conditions at Detroit could also shift the line; cool temperatures typically favour pitchers and could reinforce the Tigers' advantage. Settlement occurs on 23 June, allowing time for postponement resolution if weather forces a reschedule, though this contingency is priced in across all platforms.

Methodology

We read Detroit Tigers vs. Houston Astros from four platform perspectives: Polymarket (on-chain CLOB), Kalshi (CFTC-regulated exchange), Betfair Exchange (sports book exchange), Smarkets (peer-to-peer betting exchange). Polymarket's live quote comes directly from the Polygon order book; the other three are listed with their platform attributes — fees, KYC, settlement currency, payment options — because a 1:1 contract comparison without API access would be guesswork.

Resolution & payout

Polymarket settles via UMA Optimistic Oracle on Polygon. A proposer posts the outcome with a bond, the two-hour window runs, then the smart contract pays USDC.

Kalshi settles USD through the CFTC-regulated clearinghouse — the cleanest variant, with heavier KYC. Betfair Exchange settles in account currency (GBP/EUR), net of 2-5% commission. Smarkets follows the same model as Betfair with a lower default 2% commission.

FAQ

Where can I trade this market with the lowest fees?

On Polymarket Alternative, 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?

Polymarket Alternative 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 Polymarket Alternative?

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