I'm not exactly sure what the true numbers are, but I do remember the last 2 times this happened.
Oct. 26, 2008: Mike Nolan gets fired before San Francisco's bye.
The 49ers hosted the Seneca Wallace-led Seahawks squad that had only one
win, so they were favored by 5.5.
San Francisco was debacled, 34-13. The team committed three turnovers and
surrendered five sacks. The Niners also had many more penalties than
the Seahawks.
Dec. 16, 2007: Bobby Petrino vanished into thin air from Atlanta. Atlanta visited Tampa Bay the following Sunday as
13-point underdogs. The Bucs destroyed them, 37-3.
Point is that firing a coach during a non-bye week leads to poor performance, lack of execution, and just overall terrible football.
I'm not saying I like the Jags -8.5/9, I just find this trend very interesting. Does anybody have any opinions?