Cardinals vs. Rams

Crossbook compares what two exchanges, Polymarket and Kalshi, charge for the same event, and publishes a permanent scored record of its own forecasts under published rules.

Tracked on one venue, with Crossbook's own call on the record.

SettledEvent date Sun, 18 Oct 2026, 20:05 UTCLast checked 18 Oct 2026, 20:00 UTC

Bid/ask midpoint · retrieved 2026-10-18T20:00:32.163Z. Venue quote-update time is unavailable. Readings can be asynchronous.

13.5%bid 13.0% / ask 14.0%24h volume $216K · liquidity $1.7Mas of 18 Oct, 20:00 UTC · not refreshed recentlyView on Polymarket

Crossbook forecast

19.8%against a market price of 12.5% at the timeYES

Logged 13 Oct 2026, 15:02 UTC · Brier 0.6440

The Rams (2-3) host the Cardinals (1-4) at SoFi Stadium, fitting the home-better-record reference class where the visitor wins roughly a third of the time.
All-time head-to-head favors the Rams (53 wins to Arizona's 41 through 2025), a weak but directionally consistent anchor.
Arizona's injury situation is materially worse: RB James Conner and OT Paris Johnson Jr. are on injured reserve, with OL Isaiah Adams out and two more defenders questionable — signal, not narrative, for a weakened road underdog.
Jacoby Brissett being listed as Arizona's projected starter implies the Cardinals are without their franchise QB (Murray), which typically costs a team several points of win equity; this pushes the estimate below the base rate.
Countervailing signal: the Rams just lost 37-34 to Buffalo and their own record is only 2-3, and Arizona's 1-4 may overstate how bad they are; this keeps the estimate well above zero.
The Rams' only listed injury concern is safety Quentin Lake (questionable), a much lighter report than Arizona's.

What would change it: If Kyler Murray is confirmed as Arizona's starter and the Rams' injury report worsens significantly before Sunday, the Cardinals' win probability would rise toward or above the 34% base rate.

Settlement source

+7.3 probability points from the market at generation · med confidence · Polymarket

Base rate: Historically, NFL home teams win roughly 57% of games, and home teams holding the better record against a weaker-record divisional visitor win closer to 65%, implying the visiting underdog wins about 34% of the time; the all-time head-to-head also leans Rams (Arizona 41-53-2 through 2025).

Chosen by Crossbook's published selection rule (auto-v1), not by hand.

Formed blind at 27.0%, without sight of the price; published at 19.8%, the market’s 12.5% moved 50% of the way toward it by fixed rule. A cited fact (f10) is one the market had not moved toward since it was published. That check is recorded, not enforced.

Settlement

Every answer this call has been given, oldest first. Nothing is edited: a correction is a new entry beside the one it replaces.

YESsettled 18 Oct 2026, 23:19 UTC · recorded 19 Oct 2026, 06:30 UTC · read from the venuesettlement

What this call was reading

Arizona's 2026 season record is 1-4. [web:1][web:2] as of 2026-10-13 · azcardinals.com · within 14 days of this call
Los Angeles's 2026 season record is 2-3. [web:48] as of 2026-10-13 · nfl.com · within 14 days of this call
Arizona is scheduled to play Los Angeles at SoFi Stadium in Inglewood on October 18, 2026, at 4:05 p.m. ET. [web:51] as of 2026-10-07 · fox.com · within 14 days of this call
Through the 2025 season, Arizona had 41 wins, 53 losses, and 2 ties against Los Angeles in 96 games. [web:33] as of 2025-12-31 · champsorchumps.us
A matchup injury listing reports Arizona offensive lineman Isaiah Adams and safety Andrew Wingard out, and defensive lineman Walter Nolen III and linebacker Karson Sharar questionable. [web:88] as of 2026-10-13 · foxsports.com · within 14 days of this call
Arizona reported that offensive tackle Paris Johnson Jr. and tight end Hunter Long were placed on injured reserve. [web:84] as of 2026-10-11 · azcardinals.com · within 14 days of this call
James Conner is listed on injured reserve with a foot injury. [web:76] as of 2026-10-12 · espn.com · within 14 days of this call
A matchup listing identifies Jacoby Brissett and Matthew Stafford as the projected starting quarterbacks for Arizona and Los Angeles, respectively. [web:93] as of 2026-10-13 · arsenalsports.ca · within 14 days of this call
Los Angeles's most recent result was a 37-34 loss to Buffalo on October 12, a three-point margin. [web:48] as of 2026-10-12 · nfl.com · within 14 days of this call
Arizona's most recent result was a 45-21 loss to Detroit on October 11, a 24-point margin. [web:15] as of 2026-10-11 · nfl.com · within 14 days of this call
The Rams' injury report lists safety Quentin Lake with a hip injury and questionable status. [web:97] as of 2026-10-13 · therams.com · within 14 days of this call

Polymarket prices this at 13.5%. No verified equivalent is currently listed on the other venue, so there is no cross venue comparison on this page.

Volume over the last 24 hours is active, at about $216,368 on the busier venue.

This market has settled. The page is kept as a record of what the market said while the question was open, and of what Crossbook called.

Related markets

Crossbook publishes every forecast it makes, timestamped before the answer is known and scored against the market afterwards. See the public record and the rules it is held to.

This call is line t-0244 of the public append-only ledger, committed when it was published. It appears on the record alongside every other call, resolved and open.