Granby: Murphy Cassone vs Tristan Schoolkate

Platform comparison

Market context

The Granby tennis match between Murphy Cassone and Tristan Schoolkate, originally set for 10:00AM ET on 13 July 2026, is the underlying event driving a Polymarket contract now pricing at 100% YES for Cassone advancing. On-chain, this USDC-denominated position on the Polygon network reflects conditional tokens that settle exclusively to the winner or a 50-50 split if the match is cancelled, tied, delayed beyond seven days, or ends in a walkover.

Historically, such 100% implied probabilities in tennis prediction markets often signal a pre-match withdrawal or walkover rather than a completed contest, as seen in prior ATP events where one player withdrew before the first serve, triggering automatic 50-50 resolutions despite odds suggesting a clear winner. In those cases, the market’s mechanical rules overrode the crowd’s initial confidence, turning a seemingly certain outcome into an even split.

Traders should monitor official ATP withdrawal announcements and the Granby tournament schedule for any changes to the match status, particularly given the tight settlement window ending 20 July 2026. A recent ATP update noted increased player withdrawals at lower-tier events due to scheduling conflicts, which could directly impact whether this match proceeds or resolves as a walkover [1].

Sources: 1

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). That keeps the comparison honest — a single canonical probability across the row, with the venue-by-venue trade-offs spelt out in the columns next to it.

Resolution & payout

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

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.

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.

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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Kalshi UK trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.