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Predictions graded

Naomi Osaka #13Japan0Elena Rybakina #2Kazakhstan2

Sets 1-6 · 4-6Mon 7 Sept 2026, 20:10 Predictions gradedFourth RoundHard

Predictions4–640%

Edges2–340%

Player Profiles

Ranking advantageElena Rybakina · 11 places

Naomi Osaka

Japan

Former world No. 1 and four-time major champion, with all four major titles won on hard courts. She returned from maternity leave in 2024 and reached the 2025 Montreal final and US Open semifinal.

Current ranking: #13
Peak ranking: #1 · 2019
Current age: 28
Preferred surface: Hard
Hand: Right handed
Height: 180 cm

Elena Rybakina

Kazakhstan

Reached career-high No. 2 on 16 March 2026. The ITF lists hard as her preferred surface.

Current ranking: #2
Peak ranking: #2 · 2026
Current age: 27
Preferred surface: Hard
Hand: Right handed
Height: 184 cm

Quick Take

Pre-match view

Context last updated 6 Sep 2026, 16:36 · Europe/Bucharest

Rybakina is a slight favorite based on H2H and hard-court form, but Osaka's US Open run keeps it competitive.

Expect a long match with strong serving, making over 22.5 total games and over 2.5 sets attractive bets. Osaka +2.5 game handicap is also a solid play.

Context

Rybakina, ranked No. 2, is a powerful server and one of the tour's top hard-court players.
Her retirement against Swiatek was the only recent physical interruption, and she has looked comfortable in New York with straight-set wins. The concern is moderate, but Osaka may test her endurance if the match goes long.
- On 2026-08-20, Rybakina retired at 4-1 down to Iga Swiatek in a hard-court match.
- Since then, she has won three matches at the US Open, all in straight sets, including a 7-6(6) 6-3 win over Starodubtseva.
Rybakina, the WTA No. 2 and right-hander, retired from her Cincinnati quarterfinal on 20 August with a left-ankle problem and said she had several days of painful walking and seven days away from the practice court.
The ankle issue and lost practice time are preparation concerns, but she has since won three straight matches at the US Open in straight sets, suggesting she has managed the problem well enough to compete. Her recent form reduces the risk that the interruption will directly shape this match.
- The Cincinnati retirement followed an on-court medical evaluation after Rybakina struggled to push off on serve.
- The interruption reduced her practice time immediately before the US Open.
- Stored recent sample: 4 wins from 5 tracked matches.
- A tracked match on 2026-08-20T00:00:00.000Z against Iga Swiatek ended by retirement; the stored result was L.
ReportedSources checked 6 Sep 2026, 16:35 · Europe/BucharestWTAwww.wtatennis.com · 20 Aug 2026US Openwww.usopen.org · 5 Sep 2026
Osaka, ranked No. 13, is a four-time Grand Slam champion known for her aggressive baseline game.
The extra sets and long rallies could leave her slightly less fresh than Rybakina, who has had quicker wins. However, Osaka's ability to close out tight matches is a positive sign for her chances in another close contest.
- Osaka beat Mertens 6-3 3-6 7-5 on 2026-09-06 and Siniakova 6-2 5-7 6-1 on 2026-09-03.
- Her last three hard-court matches averaged 104.7 minutes, compared to Rybakina's 103.1 minutes over her last 13 hard-court matches.
The two met in the round of 16 at the Canadian Open on August 11, 2026.
Rybakina's comeback win gives her a psychological edge, but Osaka pushed her to a third set and will believe she can reverse the result. The match is likely to be close again.
- On 2026-08-11, Rybakina defeated Osaka 4-6 7-6(5) 6-4 in the Canadian Open round of 16.
- Rybakina hit 15 aces in that match, while Osaka had 3 aces and 6 double faults.

BetBugs edges

Compare BetBugs' chances with the market's.

BetBugs probabilities

How likely BetBugs thought each outcome was.

Result1 of 1 landed

Signal quality Medium · Uncertainty band Lean · Market price 1.75
The read
Rybakina's recent H2H win and stronger hard-court form give her the edge, though Osaka's current US Open run keeps it competitive.
- Rybakina leads H2H 1-0, winning 4-6 7-6(5) 6-4 on hard court on 2026-08-11.
- Rybakina's last 15 hard-court record is 11-2 (84.6%), while Osaka's is 8-2 (80%).
- Rybakina's last 15 overall record is 12-3, same as Osaka's 12-3, but Rybakina has a higher ranking (2 vs 13).
BetBugs · Match WinnerwonElena RybakinaEstimated chance62%

Games2 of 4 landed

Signal quality Medium · Uncertainty band Strong lean · Not priced
The read
The competitive H2H and both players' tendency for long matches support a high total games line.
- Their H2H match had 33 games (4-6 7-6 6-4).
- Osaka's last 15 matches average 21.7 games per match.
- Rybakina's last 15 matches average 21.2 games per match.
- Both players have high three-set rates: Osaka 40% (6 of 15), Rybakina 33% (5 of 15).
BetBugs · Total GameslostOver 21.5Estimated chance65%
Signal quality Medium · Uncertainty band Lean · Not priced
The read
Osaka is competitive enough to keep the match close, making the +3.5 handicap a solid play.
- H2H match was decided by 1 game (Osaka lost 16-17).
- Osaka's last 15 matches have an average game differential of +1.3.
- Rybakina's last 15 matches have an average game differential of +1.1.
BetBugs · Game HandicapwonNaomi Osaka +3.5Estimated chance62%
Signal quality Medium · Uncertainty band Lean · Market price 1.73
The read
The first set is likely to be closely contested given both players' serving strength and recent form.
- H2H first set had 10 games (6-4).
- Osaka's last 15 first sets average 9.8 games.
- Rybakina's last 15 first sets average 9.6 games.
- Both players have strong serves, leading to tight first sets.
BetBugs · Set 1 Total GameslostOver 9.5Estimated chance60%
Signal quality Low · Uncertainty band Slight lean · Not priced
The read
The second set could be tight if Osaka responds, as she did in their previous meeting.
- H2H second set had 13 games (7-6).
- Osaka's last 15 second sets average 10.1 games.
- Rybakina's last 15 second sets average 9.9 games.
BetBugs · Set 2 Total GameswonOver 9.5Estimated chance55%

Sets1 of 3 landed

Signal quality Medium · Uncertainty band Lean · Market price 2.20
The read
The competitive nature of this matchup and both players' three-set frequency make a deciding set likely.
- H2H match went to three sets.
- Osaka has played 6 three-set matches in her last 15 (40%).
- Rybakina has played 5 three-set matches in her last 15 (33%).
- Both players have high deciding-set win rates: Osaka 65%, Rybakina 58%.
BetBugs · Total SetslostOver 2.5Estimated chance58%
Signal quality Low · Uncertainty band Slight lean · Not priced
The read
Rybakina's strong first-set performance and H2H edge support a slight lean, but Osaka's recent form makes it close.
- Rybakina won the first set in their only H2H meeting 6-4.
- Rybakina's first-set win conversion is 91% career, Osaka's is 90%.
- Rybakina has won the first set in 11 of her last 13 hard-court matches.
BetBugs · Set 1 WinnerwonElena RybakinaEstimated chance55%
Signal quality Low · Uncertainty band Near coin-flip · Not priced
The read
Osaka has shown resilience in second sets, and the H2H suggests she can push back after losing the first set.
- Osaka won the second set 7-6(5) in their H2H meeting.
- Osaka's second-set win rate in last 15 matches is 60% (9 of 15).
- Rybakina's second-set win rate in last 15 matches is 53% (8 of 15).
BetBugs · Set 2 WinnerlostNaomi OsakaEstimated chance50%

Match stats0 of 1 landed

Signal quality Medium · Uncertainty band Lean · Not priced
The read
Both players are strong servers, and their combined ace averages exceed the line.
- Osaka averages 7.5 aces per match in last 15, Rybakina 6.4.
- Combined average is 13.9 aces per match.
- H2H match had 18 aces (Osaka 3, Rybakina 15).
BetBugs · Total Acesnot gradableOver 12.5Estimated chance62%
Signal quality Medium · Uncertainty band Lean · Not priced
The read
The serving strength of both players and their recent tiebreak frequency make a tiebreak likely.
- H2H match had a tiebreak in the second set.
- Osaka has played 4 tiebreaks in her last 15 matches.
- Rybakina has played 5 tiebreaks in her last 15 matches.
- Both players have strong serves, increasing tiebreak likelihood.
BetBugs · Tiebreak in MatchlostYesEstimated chance60%
Signal quality Low · Uncertainty band Slight lean · Not priced
The read
Both players have moderate double fault rates, and the pressure of a Grand Slam fourth round could increase errors.
- Osaka averages 2.9 double faults per match, Rybakina 4.1.
- Combined average is 7.0 double faults per match.
- H2H match had 12 double faults (6 each).
BetBugs · Total Double Faultsnot gradableOver 6.5Estimated chance55%

Prediction history

Elena Rybakina has been moderately reliable when projected to win

Elena Rybakina has fulfilled 9 of 14 win projections, a 64% success rate. Her average estimated probability was 77.7%, but she won only 64% of those matches, underperforming the expected 10.9 wins. All five misses were losses, with no draws or subject wins, indicating that when she fails to win, she loses outright.

Recent evidence for Elena Rybakina14 matches

Date / competitionMatch resultPredictedActualResult

4 Jul·WTA Wimbledon

#27Elise Mertens2-0#2Elena Rybakina

BetBugsElena Rybakina to win·78%

Missed

4 Jul 2026

WTA Wimbledon

#27Elise Mertens2-0#2Elena Rybakina

Elena Rybakina to win

78%probability

Elise Mertens won

Missed

2 Jul·WTA Wimbledon

#50Catherine Mcnally0-2#2Elena Rybakina

BetBugsElena Rybakina to win·72%

Matched

2 Jul 2026

WTA Wimbledon

#50Catherine Mcnally0-2#2Elena Rybakina

Elena Rybakina to win

72%probability

Elena Rybakina won

Matched

30 Jun·WTA Wimbledon

#154Lois Boisson1-2#2Elena Rybakina

BetBugsElena Rybakina to win·92%

Matched

30 Jun 2026

WTA Wimbledon

#154Lois Boisson1-2#2Elena Rybakina

Elena Rybakina to win

92%probability

Elena Rybakina won

Matched

18 Jun·WTA Berlin

#35Alexandra Eala2-0#2Elena Rybakina

BetBugsElena Rybakina to win·78%

Missed

18 Jun 2026

WTA Berlin

#35Alexandra Eala2-0#2Elena Rybakina

Elena Rybakina to win

78%probability

Alexandra Eala won

Missed

12 Jun·WTA London

#2Elena Rybakina1-2#73Katie Boulter

BetBugsElena Rybakina to win·78%

Missed

12 Jun 2026

WTA London

#2Elena Rybakina1-2#73Katie Boulter

Elena Rybakina to win

78%probability

Katie Boulter won

Missed

Head-to-Head

0-1 (1 meetings)

L4-6 7-6(5) 6-4Naomi Osaka#13vElena Rybakina#2Aug 11, 2026

1 total meetings

Previous match context available

Naomi Osaka

12W 3L

6-3 3-6 7-5#20Elise Mertens 6-2 5-7 6-1#42Katerina Siniakova 7-6(6) 7-6#101Anastasia Zakharova

4-6 7-6(5) 6-4#2Elena Rybakina

6-4 6-4#33Leylah Annie Fernandez

6-1 6-2#20Elise Mertens

6-2 6-4#68Panna Udvardy

6-4 6-2#18Alexandra Eala

4-6 6-4 6-3#67Elisabetta Cocciaretto

6-3 3-1 ret.#60Ashlyn Krueger

7-6(4) 6-4#7Karolina Muchova

6-2 7-6(2)#1Aryna Sabalenka

6-1 6-3#61Daria Kasatkina

6-3 6-2#192Anastasia Gasanova

6-1 7-5#114Elsa Jacquemot

Elena Rybakina

12W 3L

7-6(6) 6-3#58Yuliia Starodubtseva

6-2 6-4#105Jessica Bouzas Maneiro

6-3 6-2#585Thea Frodin

4-1 ret.#8Iga Swiatek

6-4 6-4#16Diana Shnaider

6-4 7-6(2)#41Magdalena Frech

6-3 6-4#96Taylor Townsend

6-2 6-3#8Iga Swiatek 5-7 6-2 6-2#4Cori Gauff

4-6 7-6(5) 6-4#13Naomi Osaka

6-4 4-6 6-4#47Liudmila Samsonova

6-2 7-5#28Ann Li

6-3 5-7 6-4#61Daria Kasatkina

7-6(4) 6-1#20Elise Mertens

6-1 6-2#65Caty McNally

Stat Battle

Last 15 match performance, compared side by side.

NONaomi OsakaOsaka

Last 15

6–1

9 core stats · 2 even

Elena RybakinaRybakinaER

Naomi Osaka carries the stronger recent form — Elena Rybakina's route runs through pressure.

Serve · 4–0 · 1 even

1st Serve In56.7%+2.8pp53.9%

1st Serve Won75.2%—75.8%

2nd Serve Won51.3%+2.3pp49.0%

Aces / Match7.5+1.16.4

Double Faults / Match2.91.2 fewer4.1

Return · 0–0 · 1 even

Return Pts Won42.8%—43.2%

Pressure · 1–1

Break Pts Converted15/15 · 14/1545.2%+7.6pp37.6%

Break Pts Saved15/15 · 14/1564.6%+1.6pp66.2%

Points · 1–0

Total Pts Won53.9%+1.0pp52.9%

Shot making · 2–1Limited data · 8 vs 5

Winners / Match8/15 · 5/1528.0+7.220.8

Unforced Errors / Match8/15 · 5/1525.53.9 fewer21.6

Net Pts Won8/15 · 5/1571.4%+7.0pp64.4%

Serve · 4–0 · 1 even

56.7%1st Serve In+2.8pp53.9%

75.2%1st Serve Won—75.8%

51.3%2nd Serve Won+2.3pp49.0%

7.5Aces / Match+1.16.4

2.9Double Faults / Match1.2 fewer4.1

Return · 0–0 · 1 even

42.8%Return Pts Won—43.2%

Pressure · 1–1

45.2%Break Pts Converted15/15 · 14/15+7.6pp37.6%

64.6%Break Pts Saved15/15 · 14/15+1.6pp66.2%

Points · 1–0

53.9%Total Pts Won+1.0pp52.9%

Shot making · 2–1Limited data · 8 vs 5

28.0Winners8/15 · 5/15+7.220.8

25.5Unforced Errors8/15 · 5/153.9 fewer21.6

71.4%Net Pts Won8/15 · 5/15+7.0pp64.4%

Naomi Osaka #13Japan0Elena Rybakina #2Kazakhstan2

Player Profiles

Naomi Osaka

Elena Rybakina

Quick Take

Context

BetBugs edges

Over 22.5

Elena Rybakina

Naomi Osaka +2.5

Over 9.5

Over 2.5

BetBugs probabilities

Result1 of 1 landed

Games2 of 4 landed

Sets1 of 3 landed

Match stats0 of 1 landed

Elena Rybakina has been moderately reliable when projected to win

Head-to-Head

Naomi Osaka

Elena Rybakina

Stat Battle