Spread: FC Barcelona (-1.5)
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.
Crossbook forecast
- 44.0%against a market price of 59.5% at the timeYES
Logged 26 Aug 2026, 22:59 UTC · Brier 0.3136
- Signal: Vallecas is a historically awkward away trip for Barcelona — recent meetings there include draws and narrow Barça wins (1-1 in 2024-25, 1-0 and 2-1 type scorelines), and Rayo's high press plus small pitch suppresses favorite goal margins.
- Signal: Barcelona's superior squad and attacking output justify favorite status for the moneyline, but winning by 2+ requires both finishing efficiency and a clean defensive second half; Poisson-style modeling of a ~1.5–1.8 goal supremacy yields a cover probability in the low-to-mid 40s, not near 60%.
- Divergence note: the market at 59.5% looks rich versus my estimate; a plausible cause is over-weighting of Barcelona's early-season form/reputation by retail flow, since nothing in the away-at-Vallecas history supports a near-60% cover rate.
What would change it: Confirmed team news showing Rayo missing multiple starters (especially in defense/goal) or Barcelona fielding a full-strength XI while Rayo rotates would push my estimate toward the market's level.
Settlement source
Context
Polymarket prices this at 75%. 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 $67,257 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
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