National Bank Open: Jacob Fearnley vs Jakub Mensik

Platform comparison

Market context

Jacob Fearnley’s meeting with Jakub Mensik at the National Bank Open is priced as a clear Mensik lean in the wider tennis market, but not an overwhelming one. Tennis Temple’s bookmaker panel shows Mensik around 1.33–1.36 and Fearnley around 3.00–3.40, which implies roughly 73% to 75% for Mensik before margin; by contrast, the prediction market’s 43% YES on Fearnley implies only a 43% chance for Fearnley and 57% for Mensik, a notably tighter gap than most sportsbook and model estimates.[1][10][11]

That divergence matters because the comparison set is fairly consistent in pointing to Mensik, yet not unanimous on how strong that edge is. Tennis Tonic, The Stats Zone, Dimers and BetClan all favour Mensik, commonly in straight sets, with modelled win probabilities ranging from about 67% to 75% for Mensik and about 25% to 33% for Fearnley.[2][6][10][12][15][18] The head-to-head record is empty, so there is no prior matchup data to anchor a market move, and current ATP rankings also favour Mensik by a wide margin in the live listings.[1][13]

For traders, the main catalysts are simple: final confirmation that the match is played on schedule, any late withdrawal or walkover news, and the live order of play from the tournament. The scheduled start has been listed for 5 August at 21:00 on several score and odds feeds, but this contract resolves on advancement rather than points won, so a retirement after the match starts would still matter if one player progresses.[1][4][5][7][16] Any disruption beyond the seven-day window would push the market to 50-50, so schedule slippage is the key non-performance risk rather than a form swing.[11]

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 Best Prediction Markets UK, which mirrors the Polymarket order book directly.

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.

UK Frequently Asked Questions

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.

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 Best Prediction Markets UK trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.

What are the best prediction markets for UK traders in 2026?

For UKGC-regulated markets: Betfair Exchange (sports, politics) and Smarkets (sports, politics, lower commission than Betfair). For broader global event prediction: Polymarket (deepest liquidity, 0% fee, USDC settlement). For US-regulated option: Kalshi (USD, limited UK payment options). Most serious UK traders use a combination of Betfair for regulated sports and Polymarket for broader markets.