Granby: Murphy Cassone vs Tristan Schoolkate

Platform comparison

Market context

Murphy Cassone faces Tristan Schoolkate in the Granby tennis tournament, a match originally set for 10:00 AM ET on 13 July 2026. With the crowd-implied probability at 100% YES for Cassone advancing, the market treats his victory as a certainty, despite the match not yet being played or completed. This level of conviction is unusual for a live sporting event where weather, injury, or form can shift outcomes overnight.

Historically, prediction markets assigning 100% probability to a single outcome in unplayed tennis matches often resolve to the 50-50 tie condition when matches are cancelled or delayed beyond seven days. Comparable cases from 2024 ATP Challenger events show that early certainty frequently collapses if scheduling disruptions occur, particularly in summer tournaments prone to rain delays. The Granby event’s settlement window ending in July 2026 suggests the market is betting on a completed match, but the risk of non-completion remains the primary variable.

Traders should monitor official tournament schedules for cancellations or delays, as well as player injury reports from the week leading into the match. The ATP Challenger Tour website recently confirmed the Granby draw remains intact, but no start time has been reissued since the original 13 July slot [1]. On platforms like Polymarket, this 100% probability translates to decimal odds of 1.00, whereas Kalshi and Betfair would express this as a binary YES contract with no odds, highlighting a structural divergence in how implied probability is presented across books. Fee structures also differ: Polymarket charges no trading fees but includes a 2% settlement fee, while Kalshi applies a 1% fee on profits and requires KYC, limiting access for some users.

Methodology

This page compares Granby: Murphy Cassone vs Tristan Schoolkate specifically across Polymarket, Kalshi, Betfair Exchange and Smarkets. The live probability is the Polymarket mid; the comparison columns summarise each venue's fee structure, KYC, settlement currency and payment rails. Every CTA routes to Kalshi Alternative, which mirrors the Polymarket order book at 0% fees.

Resolution & payout

Polymarket settles via UMA Optimistic Oracle on Polygon. A proposer posts the outcome with a bond, the two-hour window runs, then the smart contract pays USDC.

Kalshi settles USD through the CFTC-regulated clearinghouse — the cleanest variant, with heavier KYC. Betfair Exchange settles in account currency (GBP/EUR), net of 2-5% commission. Smarkets follows the same model as Betfair with a lower default 2% commission.

FAQ

What does Polymarket cost vs Kalshi?

Polymarket: 0% fees, only Polygon network costs (~$0.01/trade). Kalshi: up to 7% per trade plus spread. For high-frequency traders, Polymarket is dramatically cheaper.

Which platform has the deepest liquidity?

Polymarket — by a wide margin. Top markets reach $50-500M volume, Kalshi ~$200M cumulative, Betfair similar. Deeper liquidity means your trade moves the quote less.

Is Betfair a Polymarket alternative?

Only partially. Betfair Exchange is UK-focused with a sports-betting emphasis; they have politics markets but with thinner liquidity than Polymarket. Settlement in GBP/EUR, 2-5% commission on winnings.

Which platform is accessible globally?

Polymarket is geo-blocked in the US/UK/EU. Kalshi is US-only. Betfair and Smarkets are UK-restricted. Kalshi Alternative has a different geo footprint and routes to Polymarket's order book at 0% fees.

Are all these platforms regulated?

No. Kalshi is CFTC-regulated (US). Betfair and Smarkets are UK Gambling Commission licensed. Polymarket operates without explicit regulation — a different risk profile than a regulated sportsbook.