When the Pac-12 expanded from 10 teams to 12 teams in 2011, it had a major effect on the conference’s basketball scheduling.
When there were 10 teams, each team played the other nine twice — once at home and once on the road. But with 12 teams, a symmetrical schedule was no longer possible.
Now, each team skips a road trip to one set of schools (i.e. Washington and Washington State) but in turn, does not get to host another set of schools (i.e. Oregon and Oregon State).
An outline of the 2017-18 Pac-12 schedule was released recently, and the Arizona Wildcats will not face the USC Trojans and UCLA Bruins on the road next season — and will not host the Washington schools in McKale Center, either.