Sion: Tommaso Compagnucci vs Max Dahlin

Platform comparison

Market context

Tommaso Compagnucci and Max Dahlin are scheduled to meet in a tennis match at Sion on 17 August 2026, with the market settlement window closing on 24 August. The current crowd-implied probability sits at 100% for Compagnucci, suggesting near-certainty among traders that he will advance. This extreme skew warrants scrutiny, particularly given the settlement mechanism's sensitivity to scheduling disruptions—any delay exceeding seven days without a completed match triggers a 50-50 resolution.

Historical precedent in lower-tier ATP and Challenger events shows that matches at Swiss venues rarely cancel outright, though weather delays are not uncommon in August. However, the 100% probability appears disconnected from baseline tournament completion rates; even established Challenger circuits see roughly 2–3% of scheduled matches fail to produce a winner within the settlement window. Compagnucci's ranking and recent form relative to Dahlin would normally justify favouring the Italian, but the absolute certainty priced in leaves no room for injury withdrawals, administrative postponements, or the technical tie-break scenarios outlined in the resolution criteria.

Traders should monitor official Sion tournament communications and ATP Challenger updates in early August for any scheduling changes or player withdrawals. The lack of divergence between sportsbook lines and the prediction-market probability suggests limited liquidity or information asymmetry rather than genuine consensus. Any announcement of weather concerns or venue issues in the week preceding the match could materially shift the probability, as the seven-day grace period creates meaningful tail risk for positions anchored at 100%.

Methodology

We track Sion: Tommaso Compagnucci vs Max Dahlin 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

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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like PolyGram trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.