Katie Boulter vs. Katerina Siniakova prediction, odds, picks for WTA Japan Open 2026

Using trusted machine learning and data, we have re-simulated the result of Saturday's Boulter-Siniakova women's singles match, forming part of our tennis predictions coverage.

Our leading predictive model currently gives Siniakova a 58% chance of beating Boulter at the WTA Japan Open tournament. Additionally, Siniakova has a 57% chance of winning the first set. The simulations also show Boulter (+2.5) has a 53% chance of covering the games spread, while the under 22.5 games has a 55% chance of hitting, according to our model.

Latest betting odds

We have sourced the most up-to-date betting odds in America for this match, which are listed here:

• Moneyline: Katerina Siniakova -175, Katie Boulter +144
• First Set: Boulter +130, Siniakova -164

All odds are correct at the time of publication and are subject to change.

Model picks and best bet

After matching our probabilities against the best current odds, we can reveal our picks for each of the major markets in this matchup. Plus, find our best bet for the game below:

• Moneyline: Boulter @ +144 via DraftKings
• First Set: Siniakova @ -130 via DraftKings

According to our tennis best bets, the top play to make on this match is Katie Boulter to win.

Although Boulter is less than likely to win, she provides the best value at the current available odds.

These picks are based on our probabilities matched against the implied probabilities from the current available odds.

Game info & first serve details

The WTA Japan Open match between Katie Boulter and Katerina Siniakova is scheduled to start on Saturday at 12:30 AM ET.

• Who: Katie Boulter vs. Katerina Siniakova
• Date: Saturday, October 24, 2026
• Approx. Time: 12:30 AM ET/9:30 PM PT
• Tournament: WTA Osaka, Japan Women's Singles 2026
• Round: Semifinals

All dates and times mentioned in this article are United States Eastern Time unless otherwise stated.

Conclusion

We predict Katerina Siniakova, with a 58% win probability, will likely beat Katie Boulter at the WTA Japan Open tournament.

Additional tools and information for betting safely can be found in our Responsible Gambling hub.

This article's predictions and probabilities are generated by Dimers' proprietary Tennis prediction model. Our editorial team reviews the resulting content for accuracy and presentation before publication.