Swedish Open: Andrey Rublev vs Sebastian Baez

Platform comparison

Market context

Andrey Rublev faces Sebastian Baez in the quarterfinal of the Swedish Open at Båstad, with the match scheduled to begin today. While the prediction market on Polymarket shows a 100% implied probability that Rublev advances, this figure diverges sharply from sportsbook lines and analyst models. Traditional bookmakers list Rublev at -178 moneyline, translating to roughly a 64% win chance, while predictive models from Dimers and Tennis.com assign him a 59–60% probability, leaving Baez with a meaningful 40–41% chance to win [3][6][7].

Historically, markets pricing a tennis match at 100% for a player ranked 16th against a lower-ranked opponent often signal a liquidity error or a misinterpretation of the settlement rules rather than genuine certainty. Comparable cases in ATP quarterfinals show that even clear favourites like Rublev can lose on clay if they struggle with serve consistency or face an opponent in peak form, as Baez has demonstrated in recent Bastad events [5]. The 50-50 resolution clause for cancellations or delays beyond seven days further complicates the 100% pricing, suggesting the market may be conflating “Rublev is the favourite” with “Rublev will win with zero risk.”

Traders should monitor the official start time confirmation and any injury updates from the tournament’s live feed, as clay-court matches are susceptible to weather delays or player fatigue. The Nordea Open’s schedule indicates Rublev is the projected winner, but the absence of a live score update at 14:15 CET suggests the match may not have started yet, creating a window for the 100% price to correct [2]. Any announcement of a delay or Baez’s pre-match fitness status will be the primary catalyst for price movement.

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

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.

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.