How did TCU qualify for Rose Bowl?

Answer 1

It can get complicated:

When either the champion of the Big Ten or the Pac 12 are playing for the national title (these conference champions prefer the Rose Bowl and are nearly assured a birth there), the Rose Bowl Committee selects a team to replace the potential national champion.

Revenue, quality of potential match ups, travel time and expense all play a role in the Rose Bowl's Committee's decision.

Usually, a team to be considered, it must be in the top 14 in the final rankings nationally.

There are also loyalty considerations. The Rose Bowl Committee loves to remain loyal to the Pac 12 IF it is a Pac 12 school playing for the national title. In that case, there is a strong preference to replace the Pac 12 potential champion with another Pac 12 school.

There is also this caveat - "The Big Ten chamption gets an automactic Bowl bid, PREFERENTIALLY the Rose Bowl. So go figure. It used to be automatic before the BCS.