Kalshi vs Polymarket: Washington vs. USC
Two contracts on the same event, priced by two separate crowds. Where they disagree, one of them is wrong — or the contracts are not quite the same question.
- Disagreement
- 98.9 pts
- Match confidence
- 0%
- Theoretical edge
- none
Side by side
Probability history
How confident is this match?
- Title
- 80%
- Entities
- 100%
- Dates
- 86%
- Threshold
- 100%
- Polarity
- 85%
- Rules
- 65%
Deterministic score 85%. The model read both rule sets and did not find the contracts equivalent. Last verified Oct 3, 21:03 ET.
- tie_handling_differs
A soft flag is an ambiguity the deterministic rules noticed but could not resolve. Any one of them keeps a pair out of Grade A.
- Tie handling: Kalshi rules do not explicitly specify tie resolution (defaulting to 'fair price' or potentially ambiguous if not covered by postponement/cancellation clauses), whereas Polymarket explicitly resolves ties as 50-50.
- Postponement/Cancellation handling: Kalshi has a strict 48-hour window for postponed games; if the game starts after this window or is cancelled without starting within it, it resolves to a 'fair price'. Polymarket remains open until completion regardless of delay duration, and only resolves 50-50 if canceled entirely with no make-up game.
- Resolution Source Specificity: Kalshi specifies `ncaa.com/sports/football/fbs`, while Polymarket specifies `ncaa.com`.
- Close Time Discrepancy: Kalshi closes on 2026-10-05 17:00 UTC, while Polymarket closes on 2026-10-03 23:30 UTC.
- Tie handling: Kalshi rules do not explicitly state a tie outcome (implied 'No' for USC winning if tied, or potentially ambiguous/fair price depending on interpretation of 'wins'), whereas Polymarket explicitly resolves ties to 50-50.
- Postponement/Cancellation handling: Kalshi has a specific 48-hour window rule; if the game is cancelled or doesn't start within 48 hours, it resolves to a 'fair price'. Polymarket states that if postponed, it remains open until completion, and if cancelled entirely with no make-up, it resolves 50-50. These are materially different settlement mechanisms for non-completed games.
- Close/Settlement Timing: Kalshi close time is 2026-10-05 17:00 UTC with settlement at 2026-10-03 20:00 UTC (which appears to be before the game starts, likely an error in extraction or a placeholder, but distinct from Polymarket's close time of 2026-10-03 23:30 UTC). Polymarket settlement time is unknown but typically post-game.
- Outcome Mapping Clarity: Kalshi asks 'USC wins' (YES=USC win). Polymarket asks 'Washington vs USC' with YES=Washington, NO=USC. While logically inverse, the explicit tie/cancellation rules create scenarios where they do not pay out identically.
- Outcome Mapping: Kalshi YES corresponds to 'USC wins'. Polymarket NO corresponds to 'USC' (which implies USC wins). Therefore, the mapped outcome for Kalshi YES is Polymarket NO.
- Tie Handling: Kalshi rules do not explicitly state a tie resolution mechanism in the provided text, but typically binary sports markets resolve based on winner; if no winner, it might be ambiguous or require specific interpretation of 'wins'. However, Polymarket explicitly states ties resolve 50-50. If Kalshi resolves a tie as NO (because USC didn't win) or Fair Price, this differs from Polymarke…
- Postponement/Cancellation Handling: Kalshi has a strict 48-hour window rule: if postponed but starts within 48 hours, it resolves on result; if cancelled or starts after 48 hours, it resolves to 'fair price'. Polymarket remains open until completion regardless of time delay, and only resolves 50-50 if cancelled entirely with no make-up game. A game postponed by more than 48 hours would trigger 'f…
- Close Time: Kalshi closes at 2026-10-05 17:00 UTC (allowing for late resolution/postponement), while Polymarket closes at 2026-10-03 23:30 UTC (just after scheduled start). This structural difference affects liquidity and settlement timing.
The contracts are not equivalent due to differing rules for ties and postponed/cancelled games. Kalshi uses a 48-hour cutoff for postponements leading to 'fair price' resolution, while Polymarket waits indefinitely for completion or resolves 50-50 on cancellation. Additionally, Kalshi's YES outcome corresponds to USC winning, which maps to Polymarket's NO outcome (since Polymarket NO is labeled 'USC').
Theoretical cross-market edge
Why are these diverging?
Explanation pending
An evidence-grounded explanation is written once this market gathers enough confirmed price and trade evidence. Every number on this page is already live.
Event timeline
No timeline events yet
Timeline entries appear once price or trade activity crosses a reporting threshold.
Notable trades on both venues
No sizeable trades recorded
Neither venue has printed a trade above the reporting threshold on this event in the last 24 hours.