Kalshi vs Polymarket: Houston wins
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
- 79%
- 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, 15:03 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 (implying standard 'fair price' or void if not a win), whereas Polymarket explicitly resolves ties to 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 and resolves 50-50 only if cancelled with no make-up game.
- Settlement Time/Close Time mismatch: Kalshi closes/settles on Oct 3 at 20:00 UTC (with close time listed as Oct 5, which appears to be a data anomaly in the prompt but settlement is Oct 3). Polymarket closes on Oct 3 at 16:00 UTC. The specific cutoff times differ by 4 hours.
- Resolution Source nuance: While both cite NCAA, Kalshi includes specific disclaimer language about affiliation, while Polymarket's rules are more direct regarding outcome mapping.
- Tie handling: Kalshi rules do not explicitly state how a tie is resolved (though 'fair price' or standard sports market logic might apply, it's ambiguous compared to Polymarket). Polymarket explicitly resolves ties as 50-50.
- Postponement/Cancellation handling: Kalshi has a specific 48-hour window rule for postponed games and resolves to 'fair price' if cancelled/not started within that window. Polymarket remains open indefinitely until completion if postponed, and resolves 50-50 if cancelled entirely with no make-up game.
- Overtime: Polymarket explicitly includes overtime in the win condition. Kalshi rules are silent on overtime but imply standard NCAA football rules where overtime determines a winner (no ties in regular season NCAA FBS since 2014, though UCF/Houston could theoretically have a tie if rules change or under specific circumstances, making the explicit Polymarket clause safer).
- Close/Settlement Times: Kalshi closes Oct 5, settles Oct 3. Polymarket closes Oct 3. This creates a timing mismatch for trading.
- Tie handling: Kalshi rules do not explicitly specify tie resolution (implying standard sports settlement or 'fair price' if undefined, but typically ties are distinct outcomes in binary markets unless specified). Polymarket explicitly resolves ties to 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/not started within it, it resolves to a 'fair price'. Polymarket remains open indefinitely until completion if postponed, and resolves 50-50 only if cancelled entirely with no make-up game.
- Outcome Mapping Ambiguity: Kalshi asks 'Houston wins' (YES = Houston Win). Polymarket is a two-sided market where NO = Houston Win. While the mapped outcome exists, the structural difference in how non-Houston-win scenarios (like ties or cancellations) are handled makes them non-equivalent for risk-free arbitrage.
- Tie Handling: Kalshi rules do not explicitly specify a tie outcome (implying 'Houston wins' is false if tied), whereas Polymarket explicitly resolves ties to 50-50.
The contracts are not equivalent due to differing rules for ties and postponements/cancellations. Kalshi uses a 48-hour deadline for postponed games and defaults to 'fair price' for cancellations/late starts, while Polymarket stays open indefinitely and resolves ties/cancellations to 50-50. Additionally, the close/settlement times differ by 4 hours. However, in the primary scenario where Houston wins outright within the scheduled timeframe, Kalshi YES corresponds to Polymarket NO (Houston).
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.