Kalshi vs Polymarket: Purdue vs. UCLA
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
- 0.9 pts
- Match confidence
- 0%
- Theoretical edge
- none
Side by side
Probability history
How confident is this match?
- Title
- 79%
- Entities
- 100%
- Dates
- 86%
- Threshold
- 100%
- Polarity
- 100%
- Rules
- 65%
Deterministic score 86%. The model read both rule sets and did not find the contracts equivalent. Last verified Sep 20, 02:05 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 state how a tie is handled (though 'fair price' or specific NCAA rules might apply, the provided text is silent on ties specifically, whereas Polymarket explicitly resolves ties to 50-50). More importantly, Kalshi's resolution source is `ncaa.com/sports/football/fbs` while Polymarket's is `ncaa.com`. If the game ends in a tie, Polymarket pays out 50
- **Postponement/Cancellation Logic**: Kalshi has a strict 48-hour window: if the game doesn't start within 48 hours of the original time, it resolves to a 'fair price'. Polymarket states that if postponed, it remains open until completed, and only resolves 50-50 if canceled entirely with no make-up game. This creates a divergence if the game is delayed beyond 48 hours but eventually played; Kalshi'
- Tie handling: Kalshi rules do not explicitly state a tie resolution mechanism (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, it resolves to a 'fair price'. Polymarket remains open indefinitely until completion if postponed, and only resolves 50-50 if cancelled with no make-up game.
- Resolution Source Specificity: Kalshi specifies https://www.ncaa.com/sports/football/fbs while Polymarket uses the broader https://www.ncaa.com/.
- Tie/Draw Handling: Polymarket explicitly resolves ties to a 50-50 split (or equivalent payout structure depending on implementation, but rules state 'resolve 50-50'). Kalshi's rules do not specify tie handling; typically, if the outcome is not a win for Purdue, it resolves NO, or if undefined, may resolve Fair Price. This creates a divergence in scenarios where the game ends in a tie.
- Postponement/Cancellation Handling: Kalshi has a specific 48-hour window rule: if postponed but starts within 48 hours, it resolves on result; if cancelled or not started within 48 hours, it resolves to 'Fair Price'. Polymarket states that if postponed, it remains open until completed, and if cancelled with no make-up, it resolves 50-50. These are materially different settlement mechanisms for non
- 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 logic: Kalshi has a strict 48-hour window for postponed games; if the game starts after this window or is cancelled, it resolves to a 'fair price'. Polymarket keeps the market open indefinitely until completion if postponed, and only resolves 50-50 if cancelled with no make-up game.
- Resolution Source Specificity: Kalshi specifies `ncaa.com/sports/football/fbs`, while Polymarket specifies `ncaa.com` generally.
- Market Structure: Kalshi is a binary YES/NO contract on 'Purdue wins'. Polymarket is a two-sided market where YES='Purdue' and NO='UCLA'. While often mapped together, the explicit definition of the NO outcome differs (Kalshi NO = Purdue does not win, which includes UCLA winning, ties, cancellations, etc.; Polymarket NO = UCLA wins specifically).
The contracts differ significantly in their handling of postponements and cancellations. Kalshi imposes a hard 48-hour deadline for the game to start, after which it resolves to a 'fair price' (which may not be 50-50 or based on the final result if played later). Polymarket keeps the market open indefinitely until the game is completed, resolving 50-50 only if canceled entirely. Additionally, Polymarket explicitly handles ties as 50-50, while Kalshi's rules provided do not specify tie handling, relying on the resolution source which may have different protocols.
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
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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.