St. Louis Cardinals vs. Arizona Diamondbacks

Platform comparison

Market context

The underlying event is a Major League Baseball game between the St. Louis Cardinals and the Arizona Diamondbacks, scheduled for 19 July at 4:10PM ET. In this prediction market, a YES share represents a bet that the Cardinals will win, while a NO share bets they will not. The crowd currently implies a 0% chance of a Cardinals victory, suggesting traders overwhelmingly expect Arizona to win or the game to end in a tie or cancellation.

Historically, matchups between these sides have been closely contested, with recent results showing alternating winners. The Cardinals edged the Diamondbacks 5–4 on 17 July after a ninth-inning sacrifice fly, while Arizona won 9–4 on 24 June and 5–3 on 18 July [1][2][5]. Such volatility in recent games makes a 0% implied probability unusual, as it ignores the Cardinals’ demonstrated ability to win tight contests against this opponent.

Traders should monitor the official MLB schedule for any postponement notices, as the market remains open until the game is completed if delayed. Key catalysts include starting pitcher announcements, injury updates, and weather conditions at the venue. With the settlement window ending on 26 July 2026, any cancellation without a make-up game would resolve the market at 50–50, regardless of pre-game expectations.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews St. Louis Cardinals vs. Arizona Diamondbacks across five venues. The live probability is the Polymarket mid-price, sourced directly from the on-chain Polygon order book; the comparison columns benchmark each venue on fee structure, KYC, settlement currency and payment rails. Every CTA routes to Prediction Market UK, which mirrors the Polymarket order book at 0% fees.

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?

Polymarket is geo-blocked in the US/UK/EU. The easiest 0%-fee broker into the same order book is Prediction Market UK. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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.

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 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.

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.