St. Louis Cardinals vs. Cincinnati Reds

Platform comparison

Active sub-markets

Market context

The Cardinals and Reds meet again tonight in Cincinnati, with the market sitting close to even at 48% YES on St. Louis. The last 24-48 hours have not brought a major injury shock in the data provided, so the move is largely a read on matchup and venue rather than a fresh roster change. Cincinnati’s home edge matters here: the ESPN matchup page shows the Reds at 5-2 at home and the Cardinals at 5-2 away, with the market still effectively pricing a coin flip.

For comparison, these teams have already shown how volatile this pairing can be. In a division game between evenly matched clubs, run environment and bullpen usage often decide the result more than season records, and that tends to keep probabilities compressed unless one side has a clear pitching or lineup advantage. A 48% Cardinals price implies the market sees St. Louis as marginally shorter than a true toss-up, but not enough to reflect a strong road favourite.

Traders should watch the confirmed starters, any late batting-order changes, and whether either bullpen was heavily used in the previous game. Line movement late on game day in MLB often follows pitching confirmation, especially if a starter is scratched or limited. MLB’s official game story and score page, along with ESPN’s live game listing, are the key sources to track once line-ups are posted and first pitch approaches.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track St. Louis Cardinals vs. Cincinnati Reds 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

Settlement runs on-chain. Polymarket's contract logic separates YES and NO shares as conditional tokens; at resolution the winning share lifts to $1.00 and the losing one to $0. The outcome input comes from the UMA Optimistic Oracle, which secures against bad resolution with a bond + dispute window.

Once finalised, the smart contract pays USDC to the holders' wallets within minutes — no withdrawal fees beyond Polygon network gas. Kalshi settles in USD via CFTC clearance, Betfair in account currency net of commission, Manifold in play-money mana with no cash-out.

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 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.