St. Louis Cardinals vs. Arizona Diamondbacks

Platform comparison

Market context

The Arizona Diamondbacks defeated the St. Louis Cardinals 8–7 on Sunday, 19 July 2026, after rallying from a seven-run deficit with a walk-off RBI double by Max Kepler in the 10th inning [1]. The game, played at Chase Field, concluded the three-game regular-season series between the two clubs, with Arizona winning the final contest after also taking the previous matchup 4–3 on 23 June [1][3].

On Polymarket, this contract now trades at 0% YES for a Cardinals win, reflecting the on-chain reality that the event has already settled. Conditional tokens on Polygon are effectively worthless for the “Cardinals” side, as the official final statistics confirm Arizona’s victory [1]. USDC liquidity has likely migrated to resolved positions, and the market’s settlement window extending to 2026-07-26 is moot given the game’s completion.

Historically, MLB markets that remain open post-game resolution are rare anomalies; once the official result is logged, conditional tokens settle within hours, not days. Comparable cases show that delayed settlement windows do not alter outcomes when the primary source—official MLB statistics—is unambiguous [1]. Traders should watch for any rare administrative delays in final stat uploads, though no such issues are reported for this fixture. With the result confirmed, the only relevant catalyst is the formal closure of the market on the platform, not further on-field developments.

Sources: 1 · 2 · 3

Methodology

We track St. Louis Cardinals vs. Arizona Diamondbacks across the five venues with material prediction-market liquidity. The probability shown is the live Polymarket mid; the comparison rows summarise how each venue treats the underlying contract — fees, KYC thresholds, settlement currency, deposit options. The highlighted row marks the cheapest route into Polymarket's order book.

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

Is this market available outside the US?

Polymarket itself is geo-blocked in the US/UK/EU. Always check the legal status of prediction markets in your jurisdiction before trading.

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 does Polymarket cost to trade?

Polymarket itself charges 0% — the only cost is the Polygon network fee, typically under $0.01 per transaction. Off-chain venues like Kalshi or Betfair charge 2-7% commission.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Polymarket Scam? trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.

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.