WTA Tour
M. Stoiana
K. Siniakova- Japan Women's Open: Mary Stoiana vs Katerina Siniakova30¢30%
- Game Spread: Katerina Siniakova (-3.5) vs Mary Stoiana (+3.5)57¢57%
- Set Handicap: Katerina Siniakova (-1.5) vs Mary Stoiana (+1.5)49¢49%
- Japan Women's Open: Completed Match: Mary Stoiana vs Katerina Siniakova48¢48%
- Stoiana vs. Siniakova: Match O/U 21.545¢45%
- Stoiana vs. Siniakova: Match O/U 22.541¢41%
- Stoiana vs. Siniakova: Match O/U 23.536¢36%
- Mary Stoiana vs. Katerina Siniakova: Total Sets O/U 2.535¢35%
- Set 1 Winner: Mary Stoiana vs Katerina Siniakova35¢35%
- Set 2 Winner: Mary Stoiana vs Katerina Siniakova34¢34%
- Stoiana vs. Siniakova: Set 1 Games O/U 8.568¢68%
- Stoiana vs. Siniakova: Set 2 Games O/U 8.548¢48%
Katerina Siniakova holds the ranking edge at No. 86 against Mary Stoiana's No. 114 in their Japan Women's Open quarterfinal on outdoor hard courts in Osaka. The 30-year-old Czech brings greater WTA experience and a career-high singles ranking of 27, though her 2026 singles results show inconsistency alongside strong doubles form. Stoiana, a 23-year-old American qualifier, has posted a strong recent run, defeating higher-ranked Oleksandra Oliynykova and local Moyuka Uchijima to reach the quarters after strong qualifying wins. No prior head-to-head exists. Siniakova's veteran court craft and hard-court history typically shape trader consensus around her implied probability, while Stoiana's momentum and aggressive baseline game represent the primary upset pathway in this WTA 250 matchup.
Rules
This market refers to the tennis match between Mary Stoiana and Katerina Siniakova in the Japan Women's Open, originally scheduled for October 23, 2026 at 1:30AM ET. This market will resolve to "Over" if the total number of games completed in the first set equals or exceeds 9. Otherwise, it will resolve to "Under." Any first-set tiebreak counts as one (1) game. If the match is postponed or suspended, this market will remain open until the first set has been completed. A postponement alone will not trigger a 50-50 resolution. If the match is permanently abandoned before the first set is completed, or if the first set has not been completed by November 6, 2026, 11:59 PM ET, this market will resolve 50-50, unless the outcome has already been unconditionally determined based on completed play. An outcome is considered unconditionally determined if it would have been guaranteed under every possible completion of the set played according to the match format published by the tournament organizer for that round, including whether the set is decided by a tiebreak. For example, for a line of 9.5, if play stops with the first set at 5-4, completing the set would have required at least 1 additional game, resulting in at least 10 games played, so "Over" would resolve as the winning outcome. The primary resolution source for this market will be official WTA statistics; however, a consensus of credible reporting may also be used. This market may resolve only when the listed period of play has concluded and the result can be definitively determined by the listed resolution source(s).