Wow, quite a turnaround from last time.
As for the playoff, they don't strictly pick the "best 4 teams", it's a 50/50 combination of 'best 4 teams' and 'resume'. Wisconsin isn't one of the best 10 teams in the country, but their resume is good because of the zero in the loss column.
USC, Alabama, and Ohio State are all top-5 quality-wise, but all are on the outside looking in because their resumes are lacking. You could go 10-deep with teams that would be favored vs. Wisconsin by Vegas, and yes that means something.