Chicago Cubs vs. Pittsburgh Pirates

Platform comparison

Active sub-markets

Market context

The Chicago Cubs face the Pittsburgh Pirates on 25 May at 1:35 PM ET in a regular-season MLB matchup. Current crowd-implied probability of 53% for a Cubs victory reflects modest favouritism, though the settlement window extends to 1 June, allowing for postponement resolution should weather or scheduling issues arise.

Historical matchup data shows the Cubs have held a slight edge over Pittsburgh in recent seasons, though the Pirates remain competitive within the National League Central. The 53% probability sits near the midpoint where different platforms often diverge most noticeably: Polymarket's fractional-odds equivalent would display roughly 1.89, whilst Kalshi's binary structure and Betfair's decimal-odds presentation (around 1.89–1.90) create different visual anchors for the same underlying probability. Fee structures matter here—Polymarket charges 2% on winnings, Kalshi typically 2–3% depending on volume, and Betfair's commission scales with liquidity, potentially favouring larger positions. KYC requirements also vary: Polymarket and Kalshi operate under stricter US-focused verification, whilst Smarkets' UK-EU licensing permits different customer bases.

Traders should monitor starting pitcher announcements, which typically confirm 48–72 hours before game time, as rotation changes materially shift win probability. Recent injury reports from both rosters and weather forecasts for Pittsburgh warrant attention. The Cubs' offensive consistency against left-handed pitching and the Pirates' home-field dynamics at PNC Park represent the substantive variables driving the current 53% assessment.

Methodology

This page compares Chicago Cubs vs. Pittsburgh Pirates 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.

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, PolyGram triggers a quick verification flow that finishes in 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.