Rumors, originating from Colorado, stated that the PAC 10 was going to split into North-South divisions. The north would have the California Golden Bears, Stanford Cardinal, Oregon Ducks, Oregon St. Beavers, Washington Huskies, and Washington St. Cougars. The south would feature the Arizona Wildcats, Arizona St. Sun Devils, UCLA Bruins, USC Trojans, Colorado Buffaloes and Utah Utes.

My first impression of this news was that it was mighty generous to the two new teams in the league. USC and UCLA are considered prime scheduling due to the LA market and the recruiting wealth of southern California that all western schools want as big a piece of as they can carve.

Washington, Oregon, Washington State and Oregon State have been in the conference since its beginning. If they had approved such a plan I would have been amazed. I had sketched of an idea I was thinking of to promote a PAC 10 expansion (including Utah). Well, that is now history but I feel my sketch is now needed.

Travel costs are cut by grouping teams into regional groups. The four northern schools, four California schools and the two Arizona schools and two new schools are logical divisions I will call the North, California and South. The North and South have limited interest in playing each other, but a high interest in playing the California schools. The California schools also want to play each other every year.

NCAA rules require a conference to be split into two divisions to host a championship game. How do you take that mess and make division structure that works?

One big variable that is unknown is whether the design will have eight or nine games per year. Eight games allows home field advantage to be balanced and reduces the risk of teams eliminating fellow conference members from the top 25 rankings. Nine games allows the teams not locked together to play more frequently.

Currently the PAC 10 uses a nine game round robin schedule. Every current 12 team league uses an eight game schedule. The PAC 10 coaches recently discussed eliminating a round robin for the very reason listed above, but decided the value of a full round robin outweighed the cost of additional conference losses.

Plan A: Fixed Divisions

This plan acts like a control for this discussion. The PAC 10 has expanded to 12 and must make a schedule somehow. This is the most simplistic design available to build from. The best way to compare designs is by the fraction of years teams from each rivalry pair play each other.

Rivalry pairs are listed by the postal code for their state, LA for Los Angeles, NC for Northern California and NEW for Utah and Colorado. The numbers are the fraction of years a team from one rivalry pair would play a team from another rivalry pair. The top numbers are for eight game seasons and the bottom for a nine game season.

Plan B: California Rotation

The key to this plan is that the NCAA rules do not state that the divisions have to be the same each year. The idea is that the California schools don't have to be divided once and for all between the two divisions. They can rotate between them on a four year cycle, with a home and away guaranteed with each team in each division every four years.

The California schools would also play each other permanently as crossover games, forming three groups I call California, North and South. Each school would play each team in their group every year.

With an eight game schedule each team has a remaining game that cycles among the crossover games. Since the crossovers are varying this becomes complicated. To make a home and away for this remaining game work one can set the lower bound of a cycle to 16.

With a nine game schedule this can be accomplished far more succinctly in an eight year cycle.

[Math edit: For the nine game schedule it is impossible to schedule 2/3 over eight years. This design cycles over 24 years. An eight game design with these proportions has been found with a 48 year cycle.]

Significant gains are made relative to the non-division games of the fixed design. Some cost is absorbed in the total number of games with California teams that is needed to produce a full round robin for the California teams.

This plan is the most fair, but an eight team design is a scheduling nightmare.

Plan C: California Catering

Since the California schools are the heart of the conference, make them the heart of a division. Instead of rotating the California schools between divisions you would rotate other rivalry pairs into the California division. If the rotations are even this would have the same odds for the non California schools as the above designs.

But this plan does not have to be even. The new schools don't have to be rotated in. They would have a home and away with the California schools on a four year cycle.

The three state pairs would rotate, they would not play for two years, they would play but be in different divisions for two years and then they would play in the non-California division for two years.

Either way requires a cycle of twelve years.

The state rivalry pairs must play the new teams nearly every year (every year in a nine team design) for this to work. It is interesting that the number of games between state rivalry pairs does not change for the eight and nine team designs.

The hardest part of this design might be to convince liberal leaning university presidents to accept that not all teams are equal.

This design also expands nicely to 14 teams treated like the two new teams. This brings the percentages of games with the California teams to those of the fixed design that opened this thread.