Houston Astros vs. San Francisco Giants

Platform comparison

Market context

The Houston Astros face the San Francisco Giants on 12 August at 3:45PM ET in a regular-season MLB fixture. The current 79% implied probability favours the Astros, reflecting their stronger 2026 campaign positioning relative to the Giants' rebuilding trajectory. Resolution depends on official MLB final statistics; postponement extends the settlement window to 19 August, whilst cancellation without a make-up game triggers a 50-50 split.

Historical context matters for calibrating this probability. The Astros have maintained a winning record against the Giants in recent seasons, with Houston's AL West credentials typically outpacing San Francisco's NL West standing. When comparing similar matchups between division-leading teams and mid-tier competitors, markets typically price in a 70–80% range for the stronger franchise, accounting for home-field variance and roster depth. The Giants' recent performance trajectory and any roster adjustments made before this fixture will determine whether the current 79% reflects fair value or contains exploitable edge.

Traders monitoring this market programmatically should track roster announcements through 12 August—specifically pitcher assignments, injury updates, and any last-minute lineup changes. Recent weather forecasts for the game location and any schedule disruptions affecting either team's preparation warrant attention. MLB's official injury reports, typically released 24–48 hours before game time, often shift probabilities materially when key position players or starting pitchers are ruled out. Conditional order logic should account for the postponement clause, as extended settlement windows create liquidity dynamics distinct from same-day resolution markets.

Methodology

We track Houston Astros vs. San Francisco Giants across the five venues with material prediction-market liquidity. The probability shown is the live Polymarket mid; the comparison rows summarise how each venue treats the underlying contract — fees, KYC thresholds, settlement currency, deposit options. The highlighted row marks the cheapest route into Polymarket's order book.

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.

UK Frequently Asked Questions

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'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.

Is Polymarket legal in the UK?

Polymarket is accessible to UK traders but is not UKGC-licensed. It operates under US CFTC jurisdiction. UK residents face no domestic legal prohibition on using it, but UKGC consumer protections do not apply. For UKGC-regulated alternatives, Betfair Exchange and Smarkets offer similar prediction-style markets.

Do I pay tax on prediction market profits in the UK?

UKGC-licensed platform profits (Betfair, Smarkets) are typically tax-free gambling winnings for UK individuals. Polymarket profits involve USDC crypto transactions, which HMRC treats as Capital Gains Tax events. Keep full transaction records and report via Self Assessment if gains exceed £3,000 per tax year.

How do I deposit on Polymarket from the UK?

UK traders typically fund Polymarket via Coinbase UK, Kraken or Revolut — buying USDC with GBP and transferring to a Polygon-compatible wallet (MetaMask, Coinbase Wallet). Polymarket's onboarding walks you through the bridging process. Typical GBP-to-USDC conversion costs 0.5–1%.