I don't know if that's a hard and fast rule, but I think it's already generally observed. Last year KU was 6-6, and everybody knew there was almost no chance they'd go to a bowl because, while eligible, there were too many 7-5 teams out there. Bowls must select teams with winning records before they can select a 6-6 team. I'm pretty sure that it includes 6-5 teams. If a conference doesn't have enough bowl-eligible teams for their tie-ins, then a bowl must select a team outside of the conference with a winning record before they can select a team outside of the conference with a 6-6 record. Hence why a 7-5 Ball State team might sneak into a bowl game even if they don't get a MAC tie-in, just as Northern Illinois did last season. LSU will play for the NC because they lost in Week 7 and OSU won't because they lost in Week 11. Reverse the schedules and there is no way LSU plays in NOLA