Houston Astros vs. Chicago Cubs

Platform comparison

Active sub-markets

Market context

The Houston Astros travel to face the Chicago Cubs on 23 May at 2:20 PM ET in a regular-season matchup. The current crowd-implied probability of 44% for an Astros victory reflects moderate confidence in Chicago at home, though the settlement window extends to 30 May to accommodate any postponements. Across major platforms, this market reveals structural differences: Polymarket displays the probability directly at 44%, whilst Kalshi and Betfair would express equivalent odds in decimal format (approximately 1.79 for Cubs, 2.27 for Astros), and Smarkets similarly uses decimal odds with its commission-based fee structure. KYC requirements vary significantly—Polymarket operates with lighter verification for US traders, Kalshi enforces stricter regulatory compliance, and Betfair's UK-focused infrastructure differs substantially from US-based alternatives.

The Astros enter May as a competitive AL West contender, whilst the Cubs have historically struggled against Houston in recent seasons. The Cubs' home-field advantage is material but modest in MLB contexts; teams playing at Wrigley Field win approximately 52–54% of games across full seasons, yet this particular matchup depends heavily on starting pitcher assignments and recent form. Traders should monitor roster updates through 23 May, particularly injury reports affecting either rotation or key position players, as these typically move markets 2–4 percentage points on platforms with tighter spreads like Smarkets.

Methodology

This page compares Houston Astros vs. Chicago Cubs specifically across Polymarket, Kalshi, Betfair Exchange and Smarkets. Live odds come from the Polymarket order book; the other venues' contract details are maintained manually because their APIs aren't directly comparable. Every CTA routes to PolyGram, which mirrors the Polymarket order book at 0% fees.

Resolution & payout

Settlement is the biggest difference between the four platforms: Polymarket on-chain in USDC (instant), Kalshi USD via CFTC (T+1), Betfair and Smarkets in local currency via bank withdrawal (T+1 to T+3). PolyGram routes every trade directly into Polymarket's on-chain settlement, which is why payouts land fastest.

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.

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 fast are USDC deposits?

Polygon credits deposits after 12 confirmations — usually under 30 seconds. Withdrawals follow the same path and land back in your wallet within minutes.

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.