Tanka was a student athlete attending the University of Southern California (USC). When she decided to transfer to UCLA, the athletic director at USC invoked an NCAA rule that allowed USC to prevent Tanka from playing sports at UCLA for one year. The NCAA rule only applied to student-athlete transfers within a particular conference. Tanka sued USC and the NCAA, claiming that the rule amounted to a horizontal restraint violating the Sherman Act.

Who prevails and why?