Chicago Bears vs Buffalo Bills

Start with the conditions, because they are the one thing about this game we can measure historically. Across 16 Buffalo home games in December since 2015, the median kickoff temperature was 32°F with 8 mph of wind, and 88% of them were at or below 40°F — the coldest in the sample read 22°F. Our model prices none of that: it sees +4.2 for the Bills, +1.5 for the Bears, and lands on the Bills by 5 (65%). Weather is an argument you add to that number, not one already inside it.

The sharpest unit gap in the game runs one way: the Bills offense grades +4.0 (2nd of 32) against a Bears defense at -0.9 (19th) — 4.9 points of separation on our scale, and the single biggest reason the line sits where it does. Going the other direction, the Bears offense (+1.9, 8th) meets the Bills defense (-0.2, 11th), a 2.2-point gap.

Zoom out to the full season and the model projects the Bills at 10.3 wins (favored in 13 of 17) and the Bears at 8.9 (favored in 11) — 1.3 wins apart across the year. By win probability this is the 10th-hardest game on the Bills' schedule and the 2nd-hardest on the Bears'.

Scheduling note: this is a Saturday game — one of 2 that day — so it sits outside the main Sunday slate.

The series is dead level: 3-3 across 6 regular-season meetings since 2002. They last met in 2022: Bills won 35-13 in December. Over their last 4 meetings the Bills are 2-2. History says these two are hard to separate, which is the one place it agrees with the ratings.

Does the model earn this number? In 666 of the 3266 walk-forward games it has been graded on (2013-2024, no market line used), it landed in the 60-65% range. Those favourites went 59%. The 65% on the Bills here sits in that same band, and the history runs slightly behind the claim.

Kalshi has not listed KXNFLGAME-26DEC19CHIBUF, so there is no price on the board and no edge to quote. The model's number to hold it to: Bills 65%, Bears 35%. Applying our five-point threshold, that makes Bills contracts a buy at 60c or below and Bears contracts a buy at 30c or below — anything between is inside the noise, and we pass. Week 1's KXNFLGAME contracts opened in May 2026 and the rest of the slate lists as the season gets closer; this page picks up the price automatically when it does.

Prediction markets are not sportsbooks — you trade a contract that settles at $1 or $0, not a wager against a house line. Informational only; trade responsibly.