Written before the game and kept as published. Final: Arizona Cardinals 26, Los Angeles Chargers 14 — the graded call is above.
Week 1 is the widest-error week of the season for every model, ours included — nothing about 2026 is on tape yet, and the ratings are priors, not measurements. With that stated plainly: the Chargers rate -3.2 (28th), the Cardinals -4.4 (31st), and the model opens on the Chargers by 5.5, 65% to win. Every number on this page will move more between now and kickoff than it will in any week that follows.
Zoom out to the full season and the model projects the Chargers at 4.4 wins (favored in 3 of 17) and the Cardinals at 6.0 (favored in 2) — 1.6 wins apart across the year. By win probability this is the 17th-hardest game on the Chargers' schedule and the 11th-hardest on the Cardinals'. It is the softest spot on the Chargers' entire schedule.
No unit matchup in this game separates by even a point on our scale. The Chargers grade -3.5 on offense (32nd of 32) and +0.2 on defense (8th); the Cardinals -0.6 (22nd) and -3.8 (30th). Evenly-graded units on both sides of the ball is exactly the profile that produces a model line built from nothing but home field.
One team has owned this series: the Chargers are 5-2 in 7 regular-season meetings since 2002. They last met in 2024: Cardinals won 17-15 in October. Over their last 4 meetings the Chargers are 2-2. Worth saying plainly — the model does not know any of that. It reads 2026 ratings and nothing else, so a lopsided series is a story, not a number on this page.
Does the model earn this number? In 448 of the 3266 walk-forward games it has been graded on (2013-2024, no market line used), it landed in the 65-70% range. Those favorites went 68%. The 65% on the Chargers here sits in that same band, and the history backs it.
Kalshi's KXNFLGAME-26SEP13ARILAC contract implies 50% for the Chargers against our 66% — a 15.5-point gap. No position on this game.
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.