Warsaw: Gabriela Knutson vs Sofia Costoulas

Platform comparison

Market context

Gabriela Knutson’s match with Sofia Costoulas in Warsaw is being priced very differently across venues: the prediction market is sitting at **100% YES** for Knutson, while one bookmaker-style previewing source has Costoulas around **66%** to win, and match listings show Costoulas ranked higher in the live WTA order, 159 to Knutson’s 219. That gap matters because a market pinned at 100% can reflect stale liquidity, a hung contract, or a strong belief that the outcome is already effectively decided, rather than a balanced assessment of the actual tennis edge.[5][12]

Comparable cases in tennis often show that head-to-head history and current ranking can diverge from market price when a player has a direct prior win or when live form changes late. The available head-to-head record lists Costoulas 1-0 up on Knutson, which is a small sample but still points away from a pure consensus lock on Knutson. For traders, the key signal is not just pre-match opinion but whether the contest is officially completed, because contracts like this can resolve to a split outcome if the match is cancelled, delayed beyond the settlement rules, or started but not finished.[4][6]

The main catalysts are the tournament’s official order of play, any last-minute court or weather changes, and whether either player withdraws before first ball. Live score pages and match trackers currently list the fixture as scheduled, which supports the view that the decisive issue is participation rather than a rerun of the pricing debate. If the match begins, in-play developments will matter less for this contract than the final advancement status; if it does not start or is abandoned under the market’s rules, the 50-50 fallback becomes relevant.[2][7][9]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Warsaw: Gabriela Knutson vs Sofia Costoulas across five venues. The live probability is the Polymarket mid-price, sourced directly from the on-chain Polygon order book; the comparison columns benchmark each venue on fee structure, KYC, settlement currency and payment rails. Every CTA routes to Best Prediction Markets, which mirrors the Polymarket order book at 0% fees.

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

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.