Houston Astros vs. Chicago Cubs

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Active sub-markets

Market context

The Houston Astros travel to Chicago to face the Cubs on 23 May at 2:20pm ET in a regular-season matchup. The crowd-implied probability of 44% for an Astros victory suggests the market views this as a Cubs-favoured fixture, though the gap between the teams' recent form and historical records warrants closer examination.

Over the past five seasons, the Astros have won the season series against the Cubs more often than not, and Houston's roster depth in both starting rotation and bullpen typically edges Chicago's in May matchups. The Cubs, however, have shown improved consistency this year and play at Wrigley Field, where they hold a meaningful home-field advantage. Historical data from similar mid-May contests between these franchises shows the favourite rarely commands more than 55% implied probability, suggesting the current 44% for Houston may undervalue their recent track record and pitching advantage.

Key variables for traders include the confirmed starting pitchers—Houston's rotation has been more reliable than Chicago's through April and early May—and any late roster moves or injury updates released before first pitch. Recent weather forecasts for Chicago should be monitored, as cool temperatures in late May can suppress offensive output. The settlement window extends to 30 May, allowing for postponements, though May weather delays in Chicago are less common than in earlier months. Monitor team news from both clubs' official sources and MLB injury reports through 22 May for any last-minute changes that could shift the probability meaningfully.

Methodology

We track Houston Astros vs. Chicago Cubs on the five venues with material liquidity for prediction markets. Live odds come from the Polymarket Polygon order book — the only source that ships real-time data under an open licence. For Kalshi, Betfair and Manifold we list platform attributes (fee, KYC, settlement, payment) instead of fabricated odds, because their APIs use non-comparable contract definitions.

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

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 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.