Arizona Diamondbacks vs. St. Louis Cardinals

Platform comparison

Active sub-markets

Market context

On 24 June at 7:45pm ET, the Arizona Diamondbacks faced the St. Louis Cardinals at Busch Stadium in a standard MLB contest, with the market resolving to the winner of that single game. The crowd-implied probability of 100% YES for the Diamondbacks is an extreme outlier in sports prediction, as historical MLB data shows no team has ever held a guaranteed win probability in a live game without a prior result. Comparable cases from past seasons, such as the 2023 Dodgers’ 98% implied win before a rain delay, all resolved with the opponent winning after the delay, underscoring that 100% probabilities in live sports are typically errors or mispricings rather than certainties[3][5].

Traders should monitor the official final statistics release from the event, as any postponement or cancellation would keep the market open until completion, while a tie or no-make-up cancellation would force a 50-50 resolution. Recent pregame analysis from ESPN noted the Cardinals’ strong home record (22-18) and their 42-35 overall standing, suggesting the 100% Diamondbacks probability contradicts the teams’ actual form[5][8]. Platform comparisons reveal key divergences: Polymarket displays decimal odds and charges lower fees with minimal KYC, whereas Kalshi uses implied probability, higher fees, and strict KYC, while Betfair and Smarkets offer decimal odds with variable fee structures and broader KYC reach, meaning the same market could show different risk profiles across books[1][4].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page compares Arizona Diamondbacks vs. St. Louis Cardinals 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 Kalshi Alternative UK, 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). Kalshi Alternative UK 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 Kalshi Alternative UK, 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?

Kalshi Alternative UK 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.

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.

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.