Arizona Diamondbacks vs. St. Louis Cardinals

Platform comparison

Active sub-markets

Market context

The underlying event is an MLB matchup between the Arizona Diamondbacks and the St. Louis Cardinals, played at Busch Stadium on 22 June at 7:45 PM ET, where the winner is the sole resolution condition for the prediction market. Historical precedents show that when a market implies a 0% chance for one side, it often reflects a severe consensus mispricing rather than an actual impossibility, especially in mid-season games where pitching rotations and recent form shift rapidly. Comparable cases from the 2024 and 2025 seasons reveal that such extreme probabilities frequently correct within days once injury reports or lineup confirmations are released, suggesting the current 0% figure may be a contrarian value spot rather than a settled fact.

Traders should monitor starting pitcher confirmations, particularly Merrill Kelly’s recent ERA of 2.25 against the Cardinals and Andre Pallante’s 3.20 ERA over his last seven starts, as these metrics directly influence win probability. Recent coverage from MLB.com notes that Kelly holds a 2-1 record in four career games versus the Cardinals, while Pallante has struck out 33 batters across his past seven outings, making these stats critical catalysts for reassessing the market. Additionally, any late announcements regarding bullpen usage or defensive lineups could shift the implied probability, as the consensus currently overlooks the potential for a Diamondbacks upset despite the 0% YES figure.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Arizona Diamondbacks 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 Who Will Win, 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?

Who Will Win 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.

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.

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.

Do I need to KYC for this market?

Not under $1,500 of lifetime trading volume. Above that threshold, Who Will Win triggers a quick verification flow that finishes in minutes.