Why has it been so long since Stanford and Arizona last played?

Arizona and Stanford haven't played since 2012
Kyle Terada/Kyle Terada-USA TODAY Sports

The last time that Stanford and Arizona met was in 2012. That means that when the Cardinal beat the Wildcats 54-48 that season the iPhone 5 had just been released. 

For a conference that used to feature a true round-robin format, three years seems like an awful long time for conference opponents to miss each other.

The series between Arizona and Stanford dates back to 1979; however, due to the expansion of the Pac-12, the Wildcats and Cardinal somehow missed each other for 36 months. 

The Pac-12's four California schools insisted on playing each other every year when the conference was split into two-divisions in 2011. That means Stanford plays all five teams in the North, plus USC and UCLA every season. That leaves the Cardinal only two other Pac-12 South opponents to face each season. 

The Cardinal's other two games rotate between one Arizona school and one Mountain school on a home-and-home basis. Stanford played Utah and Arizona State in 2013-14. 

Now, the Cardinal and Wildcats finally meet up again.

(h/t Contra Costa Times)