National Bank Open: Sara Bejlek vs Iga Swiatek

Platform comparison

Market context

Iga Świątek’s second-round meeting with Sara Bejlek in Toronto is a conventional heavy-favourite spot, which helps explain why the market is sitting at **0% YES** for Bejlek. The WTA match notes say Świątek leads the head-to-head 1-0 after a straight-sets win over Bejlek at Roland Garros this year, while Bejlek is listed around No. 38 and Świątek around No. 7 in the draw notes, a gap that typically maps to a one-way price unless there is clear injury or scheduling noise.[18][2][3]

For a bot or conditional-order workflow, the key read is that this is less about true winner probability and more about *execution risk*: if the match is officially confirmed, the market should mostly track whether the favourite starts cleanly and whether any pre-match withdrawal appears on the order of play. Comparable clay-court and hard-court meetings between top-10 players and lower-ranked opponents usually resolve in straight sets, and the prior Roland Garros meeting gives a concrete baseline for modelling game-total and 2-0 scenarios rather than upset paths.[13][17][18]

The catalysts to watch are the published start time, any change to the Toronto order of play, and late injury or retirement updates from the tournament feed. Tennis.com and WTA notes both list the match as an upcoming second-round fixture, with the WTA match notes dated for Tuesday 4 August and the tournament window running to 13 August, so a cancellation or delay beyond seven days would matter for settlement more than in-play score swings.[3][18] For programmatic monitoring, the cleanest trigger set is: event status changes, player withdrawal indicators, and whether the match begins before the settlement deadline; once play starts, a retirement that awards advancement still resolves to the advancing player under the market rules.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track National Bank Open: Sara Bejlek vs Iga Swiatek across the five venues with material prediction-market liquidity. The probability shown is the live Polymarket mid; the comparison rows summarise how each venue treats the underlying contract — fees, KYC thresholds, settlement currency, deposit options. The highlighted row marks the cheapest route into Polymarket's order book.

Resolution & payout

Settlement runs on-chain. Polymarket's contract logic separates YES and NO shares as conditional tokens; at resolution the winning share lifts to $1.00 and the losing one to $0. The outcome input comes from the UMA Optimistic Oracle, which secures against bad resolution with a bond + dispute window.

Once finalised, the smart contract pays USDC to the holders' wallets within minutes — no withdrawal fees beyond Polygon network gas. Kalshi settles in USD via CFTC clearance, Betfair in account currency net of commission, Manifold in play-money mana with no cash-out.

FAQ

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.

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.

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.