College football · Week 9 2026 · Saturday, October 31
Washington State vs San Diego State prediction and pick
Our Washington State Cougars at San Diego State Aztecs pick: San Diego State by 2.1, 55% to win. The forecast rates every team against the opponents it has played, this season and last, and adds home field. No betting information goes in.
An early look, 5 weeks ahead: it sharpens as the game comes up. Updated every day until kickoff, then frozen and scored. After the game this page shows who deserved to win.
Why the curves are so wide: luck. Even with both teams’ strength known exactly, one game’s bounces, kicks, calls and sequencing move the final margin by about ±12.1 points (one standard deviation, measured from every play since 2019). These forecasts carry ±16.8, so about 52% of the width is that luck; the rest is what nobody knows yet about the teams. That is why a 7-point favorite still loses about 3 times in 10.
Ours: San Diego State by 2.1Washington State win 45%San Diego State win 55%494235282114707142128354249← Washington State win bySan Diego State win by →P50P90P95
Show as a table
Outcome
Chance
Washington State win
45.0%
San Diego State win
55.0%
Middle 50%: Washington State by 9 to San Diego State by 14
50%
Middle 90%: Washington State by 25 to San Diego State by 29
90%
Middle 95%: Washington State by 31 to San Diego State by 35
95%
Exactly San Diego State by 3
6.7%
Exactly Washington State by 3
6.4%
Exactly San Diego State by 7
5.1%
Exactly Washington State by 7
4.6%
Exactly San Diego State by 14
3.3%
P50
Half of games like this end between Washington State by 9 and San Diego State by 14.
P90
9 in 10 between Washington State by 25 and San Diego State by 29.
P95
19 in 20 between Washington State by 31 and San Diego State by 35.
Coin-flip wins: the wins each team’s games were worth with only the kicks, bounces, drops and calls re-rolled, the record adjusted for luck. Luck in wins: actual wins minus what the play was worth.
Washington State vs San Diego State: questions and answers
Who will win Washington State vs San Diego State?
Our forecast picks San Diego State, with 55% to win; Washington State win 45% of the time.
What’s the spread for Washington State vs San Diego State?
Our spread: San Diego State −2.1. The betting line isn’t out yet. Ours uses no betting information, so where the two differ is where our read of the teams differs from the market’s.
When is Washington State vs San Diego State?
Saturday, October 31, 2026, at 7:00 pm ET, at Snapdragon Stadium.
Washington State at 
San Diego State
