Iga Swiatek will reach SF of US Open 2026

The event is definitively resolved as No. Iga Świątek lost to Qinwen Zheng in the US Open round of 16 on September 7, 2026, before reaching the semifinals. Although prior forecasts assigned a 40%–44% chance based on her ranking, form, experience, and favorable expectations, the completed match result is conclusive evidence. Since an eliminated player cannot later reach the semifinals, the likelihood of the event occurring is effectively zero and the posterior probability is 0%.

The event is already definitively resolved negatively. Iga Świątek lost to Qinwen Zheng in the US Open round of 16 on September 7, 2026, by a score of 5–7, 3–6. Reaching the semifinals was therefore mathematically impossible after that match. The formal resolution date of September 30 does not change the completed result, so the probability is 0%.

The event is definitively resolved as false. Iga Świątek lost to Qinwen Zheng in the US Open 2026 round of 16 on September 7, 2026, before reaching the quarterfinals or semifinals. Therefore, later tournament results cannot change the outcome. All five forecasting perspectives agree on 0%: historical base rates are irrelevant once elimination occurred; current evidence confirms the loss; incentives and game theory cannot alter a completed match; statistical uncertainty disappears after resolution; and the devil’s-advocate review finds no plausible pathway for her to reach the semifinals.

The event is already definitively resolved as No. Iga Świątek was eliminated by Qinwen Zheng in the round of 16 on September 7, 2026, losing 5–7, 3–6. Since reaching the semifinals required advancing through the quarterfinal stage, her elimination made the event impossible. The later September 30 resolution date does not change the completed outcome, so the probability that the event occurs is 0%.

The event is definitively resolved as NO. Iga Świątek was eliminated by Qinwen Zheng in the US Open round of 16 on September 7, 2026, losing 5–7, 3–6. Reaching the semifinals would have required advancing through the quarterfinals, which became impossible once she was eliminated. The later September 30 resolution date does not change the completed result.

I estimate a 40% probability that Iga Świątek reaches the 2026 US Open semifinals. The key clarification is that she has already reached the round of 16, so the event now requires two wins: against Qinwen Zheng and then against either Elena Rybakina or Naomi Osaka.

As a historical base rate, a top-tier but non-top-four seed reaching the semifinals from the round of 16 is often in the roughly 30%–45% range, depending on the draw and opponent quality. Świątek’s strong US Open record and current form place her toward the upper part of that range, but her likely quarterfinal opponent is unusually difficult.

Factor estimates:

• Win over Zheng: approximately 78%. Świątek has a 7–1 record against Zheng, is in strong recent form, and has won all three matches without dropping a set. Zheng’s momentum, power, and four consecutive three-set victories prevent this from being closer to 85% or higher.
• Quarterfinal opponent: Rybakina is the more likely opponent, probably around 65%–75%, with Osaka accounting for most of the remainder. Rybakina has been excellent through three rounds and presents a particularly difficult matchup, while Osaka’s leg issue adds uncertainty.
• Win in the quarterfinal: approximately 48% if facing Rybakina and approximately 60% if facing Osaka, assuming Osaka is reasonably healthy. This gives a weighted quarterfinal-win probability near 51%–53%.

Combining the stages gives approximately 0.78 × 0.52 = 0.41, which I round down slightly to 40% to account for uncertainty around Świątek’s physical recovery after the demanding Bouzková match and the possibility that Zheng extends the match substantially.

The positive case is supported by Świątek’s 13–1 recent record, her Toronto win over Rybakina, six straight US Open fourth-round appearances, and her ability to win pressure tiebreaks. The negative case is her uneven broader 2026 season, the close nature of the Bouzková match, Zheng’s momentum, and the likelihood of facing a healthy Rybakina.

I would therefore use 40% as the central estimate, with a reasonable uncertainty range of approximately 36%–44%. A routine win over Zheng combined with an Osaka victory over Rybakina would move the probability higher; a long Zheng match followed by a strong Rybakina performance would lower it.

Forecaster A (historical base rates): Świątek’s repeated success in reaching the second week of the US Open, including six consecutive fourth-round appearances and the 2022 title, supports a substantial semifinal probability. However, her recent US Open ceiling has often been the quarterfinal, so history suggests a figure near—but below—50%. Estimate: 40%.

Forecaster B (current evidence): Her 13–1 recent record, Toronto title, three straight-set wins, and favorable 7–1 record against Zheng are positive. Against that, Zheng has strong momentum, and Rybakina is the likely quarterfinal opponent after progressing without dropping a set. Estimate: 40%.

Forecaster C (incentives and matchup dynamics): Świątek has the stronger résumé and should be favored against Zheng, but the key event is likely a near-even quarterfinal against Rybakina. The draw gives her little margin for error, and a long match against Zheng could worsen the subsequent matchup. Estimate: 39%.

Forecaster D (quantitative decomposition): Using approximately a 78% chance of beating Zheng and about a 49% chance of winning the likely quarterfinal gives roughly 0.78 × 0.49 = 38%. Allowing for some chance of facing the more favorable Osaka matchup raises this slightly, to about 39%–40%. Estimate: 39%.

Forecaster E (devil’s advocate): The 40% estimate may be optimistic because the Bouzková match was close and physically demanding, Zheng is playing with unusual resilience, and Rybakina has looked excellent. Świątek’s lower seed and uneven broader 2026 season also argue against treating her as a near-cofavorite. Estimate: 35%.

Aggregating these views produces a final calibrated probability of 39%. This is close to the supplied research document’s central estimate of 40%, with the small reduction reflecting the difficult likely quarterfinal and uncertainty about Świątek’s level against elite power players.

Prior: The recent forecast history was 41%, 44%, and 40%, implying a baseline near 41% for Świątek reaching the semifinals given her draw, season form, and likely quarterfinal opposition. I use approximately 41% as the starting point.

Update 1 — reaching the round of 16: Her three straight-set wins, 13–1 recent record, Toronto title, and strong US Open history are positive evidence. This raises the estimate relative to a pre-tournament baseline, although much of this evidence was already reflected in the prior forecasts.

Update 2 — round-of-16 matchup: Świątek is favored against Zheng, with an estimated 75%–82% chance of winning. The favorable head-to-head record and Zheng’s four consecutive three-set matches support Świątek, while Zheng’s momentum and comeback win over Keys prevent a higher estimate.

Update 3 — likely quarterfinal: The key obstacle is a probable matchup with Rybakina. Świątek’s estimated chance in that match is only about 45%–52%. A possible Osaka quarterfinal would be somewhat more favorable, but Rybakina is the likelier opponent and has advanced without dropping a set.

Update 4 — current performance and draw: The elimination of Madison Keys is modestly favorable, but Świątek’s two-tiebreak win over Bouzková was physically demanding and less dominant than her earlier victories. Rybakina’s strong form offsets much of the benefit from Keys’ elimination.

Combining an approximately 78% chance of beating Zheng with a roughly 50%–52% weighted chance of winning the quarterfinal produces a result near 39%–41%. My final estimate is 40%. The event is plausible, but winning the likely quarterfinal remains approximately a coin flip.

Świątek has reached the round of 16 in strong overall form, winning all three matches in straight sets and going 13–1 over her last 14 matches. Her historical record against Qinwen Zheng and superior recent results make her a clear, though not overwhelming, favorite in the next round; I estimate roughly a 78% chance of reaching the quarterfinals.

The main obstacle is the likely quarterfinal. Elena Rybakina is in excellent form and has not dropped a set, while Naomi Osaka would also present a significant first-strike challenge if healthy. Świątek’s likely quarterfinal win probability is approximately 48%–52% against Rybakina and somewhat higher against Osaka, producing an aggregate quarterfinal-win estimate near 51%–52%. Multiplying these stages gives an overall probability near 40%.

The close two-tiebreak win over Bouzková and Zheng’s momentum prevent a higher estimate, while Madison Keys’ elimination, Świątek’s recent hard-court title, and her strong US Open history support the positive case. Overall, reaching the semifinals is plausible but still slightly less likely than not.

I estimate a 41% chance that Świątek reaches the semifinals. She is strongly favored, but not certain, against Zheng: her recent form, 7–1 head-to-head record, and three straight-set wins support roughly a 78%–82% win probability, while Zheng’s momentum and repeated long matches create meaningful upset risk. The likely quarterfinal is more consequential. Rybakina appears more likely than Osaka to emerge, and against Rybakina this is close to a coin flip despite Świątek’s recent Toronto win; Osaka would probably present a somewhat more favorable matchup, especially given her reported leg issue. Combining approximately an 80% chance of beating Zheng with a weighted quarterfinal win probability around 51% gives a result near 41%. Her excellent recent 13–1 run and US Open consistency support the estimate, but the close Bouzková match, an elite likely quarterfinal opponent, and her uneven broader 2026 season keep the probability well below 50%.

Forecaster A (historical base rates): 41%. Świątek has reached at least the US Open quarterfinals in each of the last three editions and won the tournament in 2022, but her recent US Open ceiling has been the quarterfinal. As the No. 8 seed facing a difficult projected quarterfinal, her historical profile supports a probability near 40%, not that of a clear favorite.

Forecaster B (current evidence): 43%. She has won her first two matches in straight sets without facing a break point and recently won the Toronto title, including a decisive victory over Rybakina. Her immediate matchup with Bouzková is favorable. The main offsetting concern is that Osaka, Keys, Zheng, or Mertens could await in the fourth round, followed potentially by a healthy Rybakina.

Forecaster C (incentives and game theory): 39%. Świątek has strong motivation and momentum after an inconsistent season, while opponents in her section have substantial incentives and the weapons to challenge her. The likely quarterfinal against Rybakina is effectively a high-stakes near-even matchup, and Świątek cannot afford a physically costly earlier round. This keeps the probability below 50% despite her current form.

Forecaster D (quantitative/statistical reasoning): 40%. Using approximate stage probabilities of 85% to beat Bouzková, 72% to win the round of 16, and 55% to win the quarterfinal gives 0.85 × 0.72 × 0.55 = 34%. Allowing for the possibility that Rybakina loses or is physically compromised, and for Świątek's favorable current form, raises the estimate into roughly the 38%–42% range.

Forecaster E (devil's advocate): 35%. The first two wins came against comparatively weaker opponents and may not reveal how she will handle elite serving and first-strike power. Her 2026 season has been uneven, and she has repeatedly fallen at the US Open quarterfinal stage. A healthy Rybakina or a dangerous power hitter could expose vulnerabilities.

Aggregating these views produces a central estimate of approximately 40%. The strongest evidence favors Świątek reaching the semifinals, but the loaded draw and likely quarterfinal against Rybakina make this a plausible but still less-than-even outcome.

I estimate a 40% probability that Świątek reaches the 2026 US Open semifinals. She has made an excellent start: two efficient straight-set wins, strong serving numbers, no break points faced, and no apparent physical strain. Her recent Toronto title, including a decisive win over Rybakina, also supports the view that her hard-court level is currently strong enough for a deep run.

However, she still needs to win three more matches, and the difficulty increases substantially. Bouzková appears a favorable third-round opponent, giving Świątek roughly an 80%–90% chance in that match. The round of 16 is more uncertain, particularly if she faces Osaka, Keys, or Zheng rather than Mertens; I would put her chances there around 65%–80%. A potential quarterfinal against a healthy Rybakina is close to an elite-level matchup, with Świątek perhaps having a 45%–60% chance depending on Rybakina’s health and form.

A representative decomposition—approximately 85% to beat Bouzková, 75% to win the round of 16, and 60% to win the quarterfinal—produces a probability near 38%. Her strong current form and Rybakina’s uncertain physical status justify rounding this to 40%, but her inconsistent 2026 season, recent US Open quarterfinal exits, and difficult projected quarter make a probability above 50% too high.

I estimate a 40% probability that Świątek reaches the 2026 US Open semifinals. The event is already at the third-round stage, so she needs only three more victories, but the projected route remains difficult.

Base rate: A No. 8 seed and former US Open champion would ordinarily have a meaningful but clearly below-even chance of reaching the semifinals, perhaps around 30–40% at this stage depending on the draw. Her recent US Open record is encouraging—she has reached at least the quarterfinals in each of the last three editions—but she has not progressed beyond the quarterfinal since winning in 2022.

Factor 1, defeating Marie Bouzková: Świątek is a strong favorite based on her recent straight-set win over Bouzková, superior offensive weight, and excellent opening-round form. I assign roughly an 85% chance.

Factor 2, winning the round of 16: The likely opponents include Osaka, Mertens, Keys, or Zheng. This is substantially more difficult than the first two rounds, particularly against Osaka, Keys, or Zheng, who can take time away from Świątek on hard courts. I assign roughly a 72–75% chance, using 74% as a midpoint.

Factor 3, winning the quarterfinal: A healthy Rybakina is a highly challenging opponent, although Świątek defeated her decisively in Toronto and Rybakina recently retired in Cincinnati. Accounting for the possibility that Rybakina is eliminated or not fully fit, I estimate Świątek's quarterfinal win probability at approximately 52–55%.

Using representative figures of 0.85 × 0.74 × 0.54 gives approximately 34%. I raise the overall estimate modestly to about 40% because the quarterfinal opponent is not certain, Świątek's Toronto title and two efficient wins are strong positive evidence, and the simple multiplication approach can understate the benefit of favorable draw developments such as Rybakina's early exit. Conversely, the estimate is held below 50% because her 2026 season has been inconsistent, the quarter is unusually strong, and her recent US Open ceiling has been the quarterfinal.

The main reasons this forecast could be wrong are an unexpectedly strong performance from Rybakina, Osaka, Keys, or Zheng; an injury or long match for Świątek before the quarterfinal; or, in the opposite direction, another routine win combined with Rybakina's physical problems. Given the research and the prior estimates of 42% and 43%, 40% is a calibrated central estimate rather than a strong directional change.

Świątek is in a favorable position after two efficient straight-set wins, with strong serving, no break points faced, and recent evidence of excellent hard-court form from her Toronto title. She should be a clear favorite against Bouzková; I estimate roughly an 85%–90% chance of winning that match.

The round of 16 is materially more difficult, with Osaka, Mertens, Keys, or Zheng possible. I estimate about a 70%–75% chance of advancing from that round. The quarterfinal is the key obstacle: a healthy Rybakina would make the matchup close, while an upset or physical limitation affecting Rybakina would improve Świątek’s route considerably. Overall, I estimate roughly a 50%–55% chance of winning the quarterfinal stage conditional on reaching it.

Combining these stages gives an overall probability in the mid-to-high 30s. Her strong current form supports a probability above the pre-tournament baseline, but her No. 8 seeding, difficult quarter, inconsistent 2026 season, and recent US Open quarterfinal exits keep the event below 40% and well short of likely. My estimate is 37%.

Prior to the tournament, a reasonable baseline was approximately 30%–35%, reflecting Świątek’s No. 8 seed, inconsistent 2026 season, recent US Open quarterfinal exits, and a difficult projected quarter containing Rybakina, Osaka, Keys, and Zheng. Her two efficient straight-set wins over Wang Xiyu and Nadia Podoroska provide positive evidence: she has looked healthy, has not dropped a set, has reportedly not faced a break point, and has conserved energy. I would apply a moderate upward update to roughly 40%–42%, rather than a large one, because the opponents so far were weaker tests. The Toronto title and recent straight-set win over Rybakina also improve the estimate, since they show strong current hard-court form and evidence she can handle the likely quarterfinal threat. However, the probability remains below 50% because she still likely needs to defeat Bouzková, then a substantially stronger round-of-16 opponent, and finally win a difficult quarterfinal—potentially against a healthy Rybakina. Approximate conditional probabilities of 85% to beat Bouzková, 70%–75% in the round of 16, and 50%–55% in the quarterfinal imply a combined probability near 30%–35%, but favorable uncertainty about the draw and Rybakina’s fitness supports a somewhat higher overall estimate. Balancing these factors and the prior forecasts of 41% and 44%, my current estimate is 40%.

1. Clarification: The event is that Świątek wins enough matches to reach the 2026 US Open singles semifinals. Given that she has already won her first-round match, this is now a conditional forecast from the second round onward, rather than a pre-tournament estimate.

2. Historical base rate: For an elite top-eight WTA player, reaching the US Open semifinals typically has a rough unconditional probability in the 25–40% range, depending on draw and form. Świątek’s own history is mixed but strong: she won the 2022 event and reached the quarterfinals in 2024 and 2025. Those recent quarterfinal exits suggest that reaching the last four is plausible but not automatic.

3. Relevant factors:

• Current form: Strongly positive. A Toronto WTA 1000 title, a Cincinnati semifinal, and a dominant first-round win indicate good hard-court level. This raises her estimate above a neutral historical baseline.
• Early-round position: Also positive. As the No. 8 seed, she should avoid most top players until the later rounds, and the first-round win was efficient, with no break points faced. However, an expected first-round victory provides only a modest update.
• Coaching and preparation: The addition of Francisco Roig and her decision to skip mixed doubles are modest positives, suggesting improved tactical focus and energy management, though these are difficult to quantify.
• Main risks: She still needs to win three further matches, including a likely difficult quarterfinal. Players such as Pegula, Rybakina, or another top opponent could make that match close. Fatigue, a poor matchup, or a bad serving day could end the run.

4. Rough decomposition: I estimate approximately 90–95% to win the second round, 75–85% to win the third round, 65–75% to win the round of 16, and 55–65% to win a likely quarterfinal against a strong opponent. Multiplying representative values gives an overall probability around 35–45%, with the current form supporting the upper part of that range.

5. Overall forecast: 43%. This is slightly above the previous 42% estimate because the tournament-opening performance and pre-US Open hard-court results confirm favorable current form. The increase is deliberately small because the first-round win was expected and the decisive quarterfinal hurdle remains ahead.

6. Why this could be wrong: The provided dossier may overstate the value of recent results, the draw may be substantially tougher than anticipated, or her recent deep North American runs may create fatigue. Conversely, a favorable draw or continued dominant serving could make the true probability closer to 50% or higher.

Ensemble estimate: Forecaster A (historical base rates) 37%, B (current form and news) 47%, C (incentives and preparation) 44%, D (draw and match-probability modeling) 40%, and E (devil’s advocate) 34%. Aggregating these gives approximately 42%. Świątek’s Toronto title, Cincinnati semifinal, strong first-round performance, coaching improvement, and decision to skip mixed doubles all support a modest upward revision from the prior 43% estimate. However, reaching the semifinals still requires winning four additional matches, likely including a difficult quarterfinal against another elite player. Her No. 8 seeding may also expose her to a challenging draw, and her recent US Open quarterfinal exits temper the positive signals. The first-round win confirms good health and form but provides only a limited update because the opponent was substantially weaker.

I estimate a 44% probability that Świątek reaches the semifinals, conditional on her having already won the first round. A top-eight seed with her Grand Slam record, 2022 US Open title, and strong recent hard-court form would typically have a meaningful but clearly sub-50% chance of winning the four remaining matches needed for a semifinal berth. The Toronto title, Cincinnati semifinal, efficient opening-round victory, and decision to skip mixed doubles are positive indicators and justify a modest increase from the prior 40% forecast. However, the estimate remains below 50% because she still must navigate three additional rounds before the quarterfinal, likely faces a high-quality opponent in the quarterfinal, has exited at that stage in the last two US Opens, and may face some fatigue after her North American hard-court preparation. The lack of a specific draw and opponent information is the main source of uncertainty.

Starting from the previous forecast of 41%, I treat that as the prior incorporating her ranking, draw position, historical Grand Slam performance, and the uncertainty of winning four additional matches to reach the semifinals. The first-round victory was highly convincing—straight sets, no break points faced, and strong first-serve performance—so it provides a modest positive update (likelihood ratio above 1), raising the estimate by roughly 3 percentage points. Her recent hard-court form is also favorable: winning Toronto and reaching the Cincinnati semifinal supports good playing conditions and confidence, adding another modest positive update. The coaching change, decision to skip mixed doubles, and apparent energy management are smaller positives, but their predictive value is uncertain. Against this, she has exited in the US Open quarterfinals in each of the last two editions, and as the No. 8 seed she could face elite opponents in the later rounds. Those factors prevent a large increase. Overall, the evidence supports a moderate rise from 41% to 44%, but reaching the semifinal still requires several difficult wins and remains less likely than not.

I estimate a 43% probability, modestly above the previous 38% forecast. Świątek has already cleared the first round comfortably, is coming off a Toronto title and Cincinnati semifinal, and appears to have improved confidence and preparation under Francisco Roig. Her 2022 US Open title and overall Grand Slam record establish that a semifinal run is well within her normal upside. However, reaching the semifinals still requires winning four additional matches, including a quarterfinal against a likely high-ranked opponent. Her recent US Open results include quarterfinal exits in 2024 and 2025, indicating a meaningful event-specific obstacle, while a No. 8 seed may leave her with a difficult later-round matchup. The strong current form warrants an upward adjustment, but not enough to make her more likely than not to reach the semifinals.

I estimate a 40% probability that Świątek reaches the 2026 US Open semifinals. She is an elite player with a prior US Open title, a 24–6 reported tournament record, and three consecutive quarterfinal appearances from 2023–2025. Her recent hard-court preparation is encouraging: she reportedly won Toronto and reached the Cincinnati semifinals, and she has already won her opening US Open match without difficulty. Those factors place her above the typical top-10 player baseline. However, reaching the semifinals requires winning several consecutive matches, including a likely quarterfinal against another highly ranked opponent. Her recent US Open record also shows a meaningful quarterfinal obstacle: she has not advanced beyond that round since winning the tournament in 2022. Her No. 8 ranking provides some seeding benefit but does not guarantee an easy draw, and the draw, opponent matchups, fatigue, and injury status remain unknown. Overall, strong current form raises the estimate into roughly the 35–45% range, but the repeated recent quarterfinal exits and normal volatility of a Grand Slam keep it well below 50%.

I estimate a 42% probability that Iga Swiatek reaches the 2026 US Open semifinals.

Historical base rate: For an elite top-10 player at a Grand Slam, reaching the semifinals is usually a roughly 25–40% outcome, depending heavily on draw and surface. Swiatek’s US Open record is stronger than average: she won in 2022 and reached the quarterfinals in 2024 and 2025, though she has not consistently converted those quarterfinal appearances into semifinals.

Positive factors include her recent hard-court form. Winning Toronto and reaching the Cincinnati semifinals indicate good preparation and match rhythm, while her reported first-round victory confirms that she has avoided an immediate upset. Her ranking and seeding should also provide a relatively favorable path through the early rounds, and she has proven Grand Slam-level ability and prior success in New York.

The principal negative factor is the quarterfinal hurdle. At that stage she is likely to face another top player, and the dossier specifically identifies Jessica Pegula as a difficult matchup after a recent Cincinnati loss. A No. 8 ranking also means she is less likely than a top-four seed to receive a structurally easy quarterfinal path. Hard courts offer Swiatek fewer margins than clay, and a single poor serving or return performance can end the run.

A rough decomposition is: about 75–80% to reach the quarterfinals given her form and seeding, multiplied by approximately 50–55% to win a likely quarterfinal against a strong opponent. This produces an overall estimate near 40–44%. I use 42% as the central estimate. The main uncertainty is the draw: a favorable quarter could raise the probability above 50%, while a difficult quarter containing another elite hard-court player could reduce it toward 30–35%.

Prior: I estimate roughly a 32% baseline probability for an elite but non-top-4-seeded player to reach the US Open semifinals. Reaching the final four requires winning several matches, and the women’s field is deep, so even a strong contender is more likely than not to fall before the semifinals.

Update for historical US Open performance: Swiatek won the 2022 title and made the quarterfinals in 2024 and 2025, but also exited in the round of 16 in 2023. This supports a modest positive adjustment, but her recent quarterfinal exits also indicate that the QF-to-SF step has been difficult. Net effect: approximately neutral to slightly positive.

Update for 2026 hard-court form: Winning Toronto and reaching the Cincinnati semifinals are strong evidence of current surface suitability and match rhythm. I apply a positive likelihood adjustment, increasing the estimate from about 32% to approximately 40%.

Update for ranking and seeding: A No. 8 ranking should provide a favorable draw relative to an unseeded player and reduce the chance of facing another elite opponent early. This raises the estimate modestly, to about 42%.

Update for winning the opening match: A comfortable first-round victory confirms fitness and immediate form, but it is weak evidence because Swiatek was heavily favored. I increase the estimate only slightly, to approximately 43%.

Offsetting risks include the unknown draw, possible fatigue, elite quarterfinal opponents such as Jessica Pegula, and Swiatek’s recent difficulty converting US Open quarterfinal appearances into semifinal berths. After accounting for those risks, my final forecast is 41%.

Forecaster A (historical base rates): Swiatek is an elite Grand Slam player and has made the US Open quarterfinals or better in three of the last four editions, including the 2022 title. However, a top-eight seed reaching the semifinals is generally far from certain, suggesting a baseline around 35–40%. Estimate: 39%.

Forecaster B (current evidence): Her 2026 hard-court preparation is unusually strong, with a Toronto WTA 1000 title, a Cincinnati semifinal, no reported injury, and a comfortable first-round win at the US Open. This supports an upward adjustment. Estimate: 48%.

Forecaster C (incentives and game theory): Her ranking and seeding should reduce the chance of facing elite opposition before the quarterfinals, but once there, other top players can create difficult matchup-specific problems; Pegula is a particular concern. Estimate: 44%.

Forecaster D (quantitative reasoning): Reaching the semifinals requires approximately five consecutive wins. Even for a top player, multiplying realistic round-by-round win probabilities produces a result in the low-to-mid 40% range, with recent form lifting her above a generic No. 8 seed. Estimate: 42%.

Forecaster E (devil’s advocate): The evidence may be overly favorable and partly inconsistent: recent US Open quarterfinal exits show that the quarterfinal is a genuine bottleneck, and the draw, fatigue, or a high-level opponent could eliminate her. Estimate: 37%.

Aggregating these estimates gives approximately 42%. I round slightly upward to 43% because she has already won her opening match and enters the tournament with excellent hard-court momentum. This remains below 50% because the event requires navigating several rounds and at least one likely match against a top-level opponent.

Iga Świątek is a strong but not overwhelming favorite to reach the semifinals. Her case is supported by winning Toronto, reaching the Cincinnati semifinals, a 2022 US Open title, and consistent recent US Open quarterfinal appearances. A top-eight ranking should also provide a relatively favorable route through the early rounds, and she has already won her opener without apparent difficulty.

However, reaching the semifinals requires winning the quarterfinal, where she has struggled recently: she reached the US Open quarterfinals in 2023, 2024, and 2025 but advanced no further in any of those editions. At No. 8, she could also face a top-four opponent in that round, while players such as Jessica Pegula remain difficult hard-court matchups. The recent hard-court title meaningfully improves her outlook, but draw strength, fatigue, and the volatility of a single Grand Slam match keep the probability below 50%. I therefore estimate a 38% chance.