National Bank Open: James Duckworth vs Christopher O'Connell

Platform comparison

Market context

James Duckworth and Christopher O’Connell were due to meet in Montreal on 2 August, but the market still sits on the match outcome rather than a settled result, so the main near-term question is whether the ATP schedule is preserved and the tie is completed within the resolution window. Tennis.com listed Duckworth as a 38% projected winner and O’Connell at 62% ahead of the round-one match, which sits close to the market’s 43% YES level for Duckworth and implies a modest lean against him.[8]

The historical frame is fairly mixed, which is important for reading a number in the low-40s rather than treating either player as a clear favourite. Duckworth leads the head-to-head 2-1 overall, and he has won their only hard-court meeting, the 2022 US Open match, while O’Connell took their 2025 Queen’s Club meeting on grass.[1][10] That split matters because the National Bank Open is played on hard courts, the surface on which Duckworth has previously had the edge in this pairing.[1][10]

For traders, the key catalysts are official ATP score updates, any rescheduling caused by weather or court backlog, and whether the match is actually started and completed before the 7-day cutoff that would force a 50-50 settlement. Flashscore still indexed the fixture as a live scheduled match, while the ATP and tennis scoreboard feeds are the relevant sources for confirmation that the contest has begun and produced a winner.[2][5] If the match is delayed, abandoned, or pushed too far beyond its original date, the resolution mechanism shifts away from the head-to-head result and into the tie state.[2]

Sources: 1 · 2 · 3 · 4 · 5

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

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.

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 Prediction Today. 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.

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.

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.