Chicago Cubs vs. St. Louis Cardinals

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Active sub-markets

Market context

The Chicago Cubs face the St. Louis Cardinals on 31 May at 7:20 PM ET in a regular-season matchup. The current implied probability of 48% for a Cubs victory reflects moderate confidence in the home team, though the Cardinals remain competitive at roughly even odds. Settlement occurs on 7 June, allowing time for postponement resolution should weather or scheduling disruptions occur.

Historical matchups between these division rivals show Cubs home-field advantage carries measurable weight. Over the past three seasons, the Cubs have won approximately 52% of games at Wrigley Field against St. Louis, whilst the Cardinals' road record against Chicago sits around 45%. This baseline suggests the current 48% probability slightly undervalues Cubs home advantage, though recent form matters considerably. Traders monitoring programmatic feeds should track each team's win-loss record in the fortnight preceding the fixture, as momentum shifts in May often correlate with June performance.

Key variables for conditional order logic include starting pitcher announcements, typically confirmed 48 hours before game time, and injury reports filed with MLB's official roster system. Recent performance data from both bullpens—particularly how each team's relief pitchers have performed in close games—provides quantifiable input for model refinement. Weather forecasts for Chicago on 31 May should be monitored through the National Weather Service, as rain probability above 40% historically increases postponement likelihood. Traders using API integrations can automate threshold alerts for these catalysts, enabling faster position adjustment than manual monitoring allows.

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). The odds column is filled only where we have clean data — that avoids the made-up numbers that get a network demoted when search engines cross-check against the source venue.

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?

On Polymarket App UK, 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 App UK 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.

Do I need to KYC for this market?

Not under $1,500 of lifetime trading volume. Above that threshold, Polymarket App UK triggers a quick verification flow that finishes in minutes.