Estimated outcome probability. A likely winner can still be overpriced.
← Decision briefsTennis · Oct 17, 2:05 AM PDT YOUR RESEARCH TASK FORECASTJelena Ostapenko RELIABILITY4/4 model reports MARKET VALUENot established Current TORK63.5% Simple average63.5% Calibrated average64.8% Kalshi46.0% Inspect the methods and progress →
Jelena Ostapenko vs Sonay Kartal
63.5%Jelena Ostapenko
LOCKED Oct 17, 1:30 AM PDT4/4 independent models select Jelena Ostapenko; all four oriented probabilities average 63.5%.
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A documented difference, its timing, and limits.
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21 reported evidence limits. Agreement alone does not establish accuracy.
A probability difference alone does not account for forecast error, fees, spread, or available liquidity.
Why the models lean this way
These are reasons recorded by the models. They are not independently verified facts or measured causes of a probability change.
- Gemini: Ostapenko's WTA rank of 34
- Claude: Ostapenko has an explicit current rank of 34 with 1,527 ranking points; Kartal's rank is not supplied
- Grok: Ostapenko rank 34 and 1527 points vs Kartal unranked
- GPT: Ostapenko has an explicit current rank of No. 34, indicating established tour level.
Read all four model reports
Gemini · Jelena Ostapenko · 62.0%
Jelena Ostapenko holds a solid WTA ranking of 34 and has more tour-level experience with 43 matches played this season. Sonay Kartal lacks ranking data but has a strong 14-7 win-loss record. Ostapenko's established ranking makes her the favorite, though Kartal's form warrants caution. Surface form, injuries, head-to-head, travel, and market odds are unavailable.
google/gemini-3.1-pro-preview · Oct 16, 8:05 PM PDTClaude · Jelena Ostapenko · 56.0%
The only usable signals are a current ESPN rank of 34 for Ostapenko (1,527 points, 23-20 season record) versus no listed rank for Kartal with a 14-7 record. Ostapenko's established top-40 standing and far larger match volume at tour level gives a modest edge, and both have reached the same semifinal round so stage context is neutral. Kartal's superior win rate (.667 vs .535) on a smaller sample partially offsets this, suggesting a near-coin-flip tilted slightly toward the ranked player. Surface-specific form, injury status, head-to-head history, travel/scheduling load, and market odds are all unavailable in this evidence package, so the estimate is deliberately kept close to even.
anthropic/claude-opus-5 · Oct 16, 8:05 PM PDTGrok · Jelena Ostapenko · 78.0%
Ostapenko holds an explicit WTA rank of 34 with 1527 ranking points and a 23-20 season record, while Kartal has no supplied rank or points and a 14-7 record. The large gap in ranking metrics favors Ostapenko in this semifinal despite Kartal's higher win percentage. Surface form, injuries, head-to-head, travel, and market odds are unavailable as they are not supplied in the evidence package.
xai/grok-4.3 · Oct 16, 8:05 PM PDTGPT · Jelena Ostapenko · 58.0%
Using only the supplied evidence, Jelena Ostapenko has the clearer proven baseline because she has an explicit current WTA rank of 34 and a larger season sample at 23-20. Sonay Kartal’s season record of 14-7 is stronger by win rate, but her current rank is unavailable in the package, which limits direct comparison of overall level. With ranking available for Ostapenko and a respectable season volume, she deserves a modest edge, but not a large one because Kartal’s better season record keeps this close. Surface form, injuries, head-to-head, travel, and market odds are unavailable in the evidence package.
openai/gpt-5.4 · Oct 16, 8:05 PM PDTWhat remains uncertain
- Surface form is unavailable
- Injuries are unavailable
- Head-to-head is unavailable
- Travel is unavailable
- Market odds are unavailable
- Surface-specific (hard court) form not provided
- Injury and fitness status not provided
- Head-to-head history not provided
What to watch next
Official result recorded. Review the original forecast and sources below.
Open the event and source context →What changed before the lock
- 2.8 percentage points lower for Jelena Ostapenko
The pre-event probability state was locked atomically and is immutable.
Record hash
01794da5bec39f7e5f61178f7f5eb3032d5ccd30d541dbb822f69f197f00a406 - First recorded forecast
First prospective probability state captured for this source and competition.
Record hash
f3d2fbf21d36471613dff2c09b3d9763c12c520f373ea09cfa77ef16d708f51e
Reasons are shown as they were recorded. The ledger does not establish that a specific fact caused a probability change.
The saved method comparison
All probabilities below refer to Jelena Ostapenko. Model inputs were fixed at Oct 17, 1:30 AM PDT. The market was observed at Oct 17, 1:25 AM PDT.
Comparison record
Saved Oct 17, 1:30 AM PDT. This is a research comparison; no method has been promoted.
943798df23c8fdfe65dec23a697da5df08c0a1690aad7d29bae705202b928b66Available source context
site.api.espn.com ↗sports.core.api.espn.com ↗sports.core.api.espn.com ↗sports.core.api.espn.com ↗sports.core.api.espn.com ↗sports.core.api.espn.com ↗
These links provide event context. They do not verify every claim in a model report.
Recorded outcome: Sonay Kartal (GBR) bt Jelena Ostapenko (LAT) 7-6 (11-9) 7-6 (7-5)
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