Spencer Johnson vs Stian Klaassen

This market covers the ITF Men Rancho Santa Fe first-round tennis match between Spencer Johnson and Stian Klaassen, originally scheduled for July 11, 2026. The head-to-head resolves to whichever player advances, per official ITF information; walkovers and unresolved delays beyond seven days settle 50-50, while in-match retirements or defaults pay out to the advancing player. Spencer Johnson is the clear favourite on Polymarket, priced at 99.5% to advance, with Klaassen at just 0.5%. That is about as lopsided as a tennis head-to-head gets on a prediction market, implying the market treats Johnson as an all-but-certain winner. Total traded volume is modest at roughly $425, so the pricing reflects a thin book rather than heavy conviction from many participants. The notable cross-platform gap sits with Azuro, which prices Spencer Johnson at 78.1% and Klaassen at 29.3% in its main match line — materially tighter than Polymarket's near-certainty. Azuro also lists a wide range of handicap and totals markets that Polymarket does not carry in resolved form. Overall, both venues agree Johnson is favoured, but Polymarket prices him as a near-lock while Azuro leaves considerably more room for an upset.