I think the Playoff or snub equation is an argument simply because it's too early to have enough information available to make a decision. That said it's a fun conversation to even be considering having at this point. So I'll help out a little bit: If there's an undefeated SEC, P10, B12, and ACC team at the end of the season, there's no chance Illinois makes the playoffs. But what is the actual likelihood of this? The answer is low as it hasn't happened in BCS or later era (past 24 years), however certain years have gotten close with 3 undefeated power 5 teams with some additionally having an undefeated minor conference team, so it is possible, just low likelihood.
So the question becomes how many power 5 conference teams are likely to stay undefeated. Well using some statistics over the past 24 years you get the following statistics based on season averages:
Undefeated P6/P5 teams: avg=1.30/season, s=1.02
Likelihood of a P6/P5 conference having an undefeated team= 30/131=22.9%
Expected number of undefeated P5 teams this year=1.15
Okay, so now we know that while somewhere between 0-3 undefeated P5 teams will occur with 95% likelihood (and less than 3% probability of 4 undefeated P5 teams), the most statistically likely situation is there will be 1 undefeated P5 team this year.
Excellent, now that we know that, what is the likelihood of other 1 loss P5 teams or a Playoff selected 0 loss Minor Conference team:
Likelihood of a P6/P5 conference having a 1 loss team= 71/131=54.2%
Likelihood of 0 loss playoff caliber minor conference teams this year=3/23=13.0%
Expected number of 1 loss P5 teams this year=2.71
Expected number of 0 loss playoff caliber minor conference teams this year=0.13
So in an average year, as Illinois would be one of the ~3 1 loss P5 conference teams or 0 loss minor conference teams, statistically, Illinois would have over a 50% shot of making the Playoffs. It's obviously not a given, but in the crazy case Illinois were to completely win out, they would have a strong and even likely though not guaranteed chance of making the 4 team playoff.
Now the real questions start with would a 1 loss Illini team be taken over a 1 loss SEC, Pac10, ACC or B12 team if 1 or 2 1 loss P5 teams must be left out of the playoffs (i.e. an abnormally high playoff caliber team year). And I hate putting this out into the ether, but what if the final playoff spot comes between a 1 loss Illinois team and a 1 loss OSU team who Illinois beats in a game of the century B10 championship game? Would Illinois automatically get the spot or could OSU with the much better loss, the name recognition and fandom, and the somewhat similar strength of schedule get the nod instead, thereby leading to the great 2022 riot/apocalypse?
That all said, we just have to take it game by game, play hard, and if we keep piling up the wins, we'll give ourselves a chance. Plus if we were to win the non-Michigan games on our schedule, then that Illinois-Michigan game is almost a defacto Rose Bowl or better play in game! That's hard to even imagine.
