Pittsburgh Pirates vs. St. Louis Cardinals

Platform comparison

Active sub-markets

Market context

The Pirates and Cardinals meet again in a series shaped by a lopsided recent head-to-head, but not by a long-term mismatch. St Louis have won five straight against Pittsburgh in the most recent sample cited by StatMuse, and the Cardinals also swept the Pirates in Pittsburgh on 30 April, taking a 10-5 win behind early damage off Paul Skenes. Over the longer run, though, the matchup has been more competitive than the latest run suggests: AI Score’s historical database has the Cardinals leading the all-time series since 2000, but not by an overwhelming margin. That makes a 0% YES price look more like an artefact of market setup than a true read on win probability, because one result in a single-game MLB market can swing the outcome completely.

For traders, the key variables are the starting pitchers, line-up availability and any late bullpen use from the previous night. The Cardinals’ recent box-score edge in this fixture has often come from getting to Pittsburgh’s starter early, as they did against Skenes in late April, while the Pirates’ path is usually tighter if their front-end pitching can keep the game in the middle innings. The official Cardinals scoreboard and ESPN’s game pages are the clearest live sources for confirmed line-ups, pitching changes and injury-related absences; any last-minute scratch or pitcher swap will matter more than the season-to-date records. If the game is rescheduled, the market stays open until completion, so the decisive information is the actual nine-inning line-up that takes the field.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Pittsburgh Pirates vs. St. Louis Cardinals 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

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.

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.

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.