the best team in the big 12 will make the 4 every year. sometimes the best two. a ccg isn't going to change that imo. in fact, the only scenario I can see where the b12 doesn't get a spot is the best team in a very down year losing the ccg to some garbage team.
With the human selection committee and weight given to conference champions, the selection thought process is going to go the following way, whether they do it on purpose or subconsciously:
1. Who are the winners of the BigTen, Big12, SEC, and Pac-12. Those 4 are the baseline. Rank those 4 teams.
2. Who won the ACC and is that team undefeated? Compare this team against team #4 above. If ACC team deserves it more than #4 on the list, replace them. Repeat with #3 on list, then #2 and #1 if deserving.
3. Who took 2nd in the SEC? Is there a better SEC team that didn't make their championship game? Repeat Step 2 with this SEC team.
4. Who took 2nd in the BigTen/SEC/Big12? Repeat Step 2 with this team. If you can't clearly make a case for this team over a team already on the list, the team on the list stays.
5. Are there any other teams who are deserving of being considered (must be an undefeated/1-loss ND or an other undefeated team). If so, repeat step 2 with those teams until all deserving teams have been considered. If you can't clearly make a case for this team over a team already on the list, the team on the list stays.
This is why I agree with SD. 90% of years the Big12 champ won't be as low #4 starting on that list. In years where the Big12 champ stars out #3 on the list it would take an undefeated ACC team AND a 1-loss SEC team to not win the SEC to knock them out. This is why 90% of the time the Big12 will have a team in and people are spending hours wasting their time trying to figure out if we need a CCG for 1 out of 10 years to maybe help out if needed. Every year the committee will automatically put the Big12 champ in unless 1-2 other non-power champs are undefeated and clearly better, which would require the Big12 champ to have 2-3 losses and winning a Conf. Champ game over another 9-3 team wouldn't help anyway.