Granby: Sasha Rozin vs Keegan Rice

Platform comparison

Market context

The Granby tennis tournament features a singles match between Sasha Rozin and Keegan Rice, originally set for 14 July 2026 at 2:30PM ET, where the winner advances to the next round. While sportsbooks on platforms like Robinhood assign Keegan Rice a clear edge at 59¢ against Rozin’s 42¢, the parallel prediction market for this contract shows a stark divergence, with the crowd-implied probability for Rozin advancing sitting at 0% YES. This near-total dismissal of Rozin contrasts with head-to-head data indicating both players hold equal career wins, suggesting the market may be overreacting to recent form or unverified injury reports rather than historical parity [1][2].

Historical precedents in lower-tier tennis events show that 0% implied probabilities often precede unexpected outcomes when one player is a late replacement or when surface conditions favour an underdog’s style, yet such cases usually retain at least a 5–10% floor to account for retirement risk. The current pricing implies a near-certainty of Rice winning or Rozin retiring before the match begins, a stance that ignores the equal career win record and the tournament’s standard tie-break resolution rules for cancellations [1]. Traders should monitor official ATP or tournament entry lists for any late withdrawals, as a retirement before the first ball would trigger the 50-50 settlement clause, while a match start followed by a retirement would still award the advance to the non-retiring player [2].

Sources: 1 · 2

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

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 Best Prediction Markets 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.

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 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.