Grade C · 0%RelatedOutcome mapping: same
Kalshi vs Polymarket: Northern Illinois 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.
Kalshi 1.0% vs Polymarket 1.8% on Northern Illinois wins — a 0.8 point prediction-market gap.
Live comparison
Kalshi
1.0%
—Polymarket
1.8%
−5.3 pts down- Disagreement
- 0.8 pts
- Match confidence
- 0%
- Theoretical edge
- none
Side by side
| Metric | Kalshi | Polymarket |
|---|---|---|
| Probability | 1.0% | 1.8% |
| 1h move | — | −12.1 pts down |
| 24h move | — | −5.3 pts down |
| 7d move | — | −30.3 pts down |
| 24h volume | $6.88M | $194K |
| Liquidity | — | $297K |
| Spread | — | 0.7¢ |
| Open interest | 4,210,744 | — |
| Closes | Nov 1, 01:59 ET | Oct 31, 22:30 ET |
| Resolution source | https://www.ncaa.com/sports/football/fbs | https://www.ncaa.com/ |
| Contract | Open → | Open → |
Probability history
Both venues on one axis, with the gap beneath
KalshiPolymarket
How confident is this match?
Deterministic scoring first; the model may only downgrade
- Title
- 84%
- Entities
- 100%
- Dates
- 86%
- Threshold
- 100%
- Polarity
- 100%
- Rules
- 69%
Deterministic score 89%. The model read both rule sets and did not find the contracts equivalent. Last verified Nov 1, 01:04 ET.
Soft flags
- 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.
Material differences
- Tie handling: Kalshi rules do not explicitly state a tie resolution mechanism (implied 'fair price' or undefined if not covered by postponement/cancellation clauses), whereas Polymarket explicitly resolves ties to 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 until completion if postponed, and resolves 50-50 if cancelled entirely 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/`.
- Market Type: Kalshi is binary (YES/NO on NIU winning). Polymarket is two-sided (NIU vs UNLV), though functionally similar for the winner, the explicit tie/cancel outcomes differ.
- Tie/Draw Handling: Kalshi rules do not explicitly state how a tie is handled (implying 'Northern Illinois wins' is false, thus NO, or potentially ambiguous/fair price depending on interpretation of 'win'), whereas Polymarket explicitly resolves ties to 50-50.
- Postponement/Cancellation Handling: Kalshi has a specific 48-hour window rule; if the game starts within 48 hours it resolves normally, otherwise it resolves to a 'fair price'. Polymarket states it remains open until completion if postponed, and resolves 50-50 only if canceled entirely with no make-up game. These mechanisms differ significantly in edge cases (e.g., postponement >48h but eventuall…
- Outcome Structure: Kalshi is a binary YES/NO contract on 'Northern Illinois wins'. Polymarket is a two-sided market where YES='Northern Illinois' and NO='UNLV'. While often mapped as equivalent for simple win/loss, the explicit inclusion of UNLV as the counterparty outcome in Polymarket vs the generic 'NO' (which includes ties/cancellations under Kalshi's strict 'wins' definition) creates settlem…
- Tie handling: Kalshi rules do not explicitly state how a tie is resolved (though 'win' implies no tie resolution or fair price), 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 if postponed, and resolves 50-50 only if cancelled with no make-up game.
- Outcome structure: Kalshi is a binary YES/NO market on 'Northern Illinois wins'. Polymarket is a two-sided market where NO represents 'UNLV wins'. While often functionally similar in non-tie scenarios, the explicit mapping of NO to UNLV vs generic NO creates structural differences in edge cases like ties or cancellations.
- Tie Handling: Kalshi rules do not explicitly state how a tie is handled (though college football rarely ends in ties, the absence of a specific rule compared to Polymarket's explicit 'resolve 50-50' creates ambiguity). More importantly, Polymarket explicitly resolves ties to 50-50, whereas Kalshi's standard binary resolution for a non-win/non-loss scenario is undefined or potentially 'fair price'…
- Postponement/Cancellation Logic: Kalshi has a strict 48-hour window. If the game starts >48 hours after the original start time, it resolves to 'fair price'. Polymarket states the market remains open until completion regardless of delay duration, and only resolves 50-50 if canceled entirely with no make-up game. This means a game postponed by 3 days would resolve differently on Kalshi (fair price…
The contracts are not equivalent due to differing settlement rules for ties and cancellations/postponements. Kalshi's 'fair price' resolution for cancellation differs from Polymarket's '50-50' resolution. Additionally, Kalshi's lack of explicit tie handling compared to Polymarket's clear 50-50 tie rule creates ambiguity in edge cases.
Theoretical cross-market edge
Grade A pairs only, from executable book prices with depth simulation
Theoretical edge is calculated only for Grade A pairs, where the two contracts appear materially equivalent for settlement analysis. This pair is graded C, so the venues are compared for probability and sentiment only.
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
Past 24 hours, ranked by notional
| Market | Venue | Time | Side | Price | Size | Notional | Before | +5 min | Move | Impact |
|---|---|---|---|---|---|---|---|---|---|---|
| Northern Illinois winsSports · Kalshi ↗ | Kalshi | 00:30 ET3 h ago | No sell | 96.0% | 15K | $14,400 | 3.5% | 8.5% | +5.0 pts up | Exceptional |
| Northern Illinois vs. UNLVSports · Polymarket ↗ | Polymarket | 23:36 ET4 h ago | UNLV buy | 75.0% | 16K | $11,959 | 24.5% | 20.0% | −4.5 pts down | Exceptional |
| Northern Illinois winsSports · Kalshi ↗ | Kalshi | 00:31 ET3 h ago | No sell | 97.0% | 5.9K | $5,715 | 3.5% | 8.5% | +5.0 pts up | Exceptional |
| Northern Illinois winsSports · Kalshi ↗ | Kalshi | 00:30 ET3 h ago | No sell | 96.0% | 5.7K | $5,519 | 3.5% | 8.5% | +5.0 pts up | Exceptional |
| Northern Illinois winsSports · Kalshi ↗ | Kalshi | 00:31 ET3 h ago | No sell | 97.0% | 5.4K | $5,221 | — | — | — | Normal |
| Northern Illinois vs. UNLVSports · Polymarket ↗ | Polymarket | 01:50 ET1 h ago | UNLV sell | 99.1% | 2.1K | $2,079 | — | — | — | Normal |