St. Louis Cardinals vs. Arizona Diamondbacks

Platform comparison

Market context

The Arizona Diamondbacks defeated the St. Louis Cardinals 8–7 in a walk-off victory on Sunday, 19 July, at Chase Field, ending the contest in the 10th inning after rallying from a seven-run deficit [2][4]. Max Kepler secured the win with an RBI double, marking a dramatic turnaround that saw the Diamondbacks overcome a significant hole to claim the game [2].

Historically, prediction markets assigning a 0% implied probability to a team that subsequently wins a game reflect a total failure to price in late-inning volatility or walk-off scenarios, similar to past MLB contracts where underdogs rallied from double-digit deficits only after markets had effectively closed on the outcome [1][2]. Such divergence between the 0% crowd-implied probability and the actual result highlights how sportsbook lines, which priced the Diamondbacks at -126 odds, often capture momentum shifts that lagging prediction markets miss until the final play [3][7].

Traders monitoring this contract should note that the settlement window extends until 26 July 2026, creating a dependency on official league confirmations rather than real-time game data, which already confirms the Diamondbacks' victory [1][5]. With probable pitchers Andre Pallante and Eduardo Rodriguez having already completed their starts, the primary catalyst for resolution is now the formal publication of final statistics by MLB, which will override any lingering market ambiguity regarding the outcome [5]. The over/under result of 15 runs against a 9-run line further underscores the high-variance nature of this fixture, a factor that should inform how similar high-scoring games are priced in future cross-platform comparisons [3].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page is a comparison snapshot: one live quote, four reference venues with their key attributes, and a single execution path — every trade button routes to Kalshi vs Polymarket, which mirrors the Polymarket order book directly.

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.

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?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Kalshi vs Polymarket 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.