Texas' 39-33 loss to Texas Tech throws the Big 12 South race into a free-for-all.
Tech leads the South with a 5-0 record, followed by OU, Oklahoma State and Texas, all at 4-1.
Texas is finished with the other three contenders, but the other three contenders haven't played each other at all. OSU plays at Tech next Saturday, OU hosts Tech on Nov. 22 and OSU hosts OU on Nov. 29.
The first tiebreaker is head-to-head results, so Texas has the edge on OU and OSU, but Tech has the edge on Texas.
In the case of a three-way tie in which the three teams were 1-1 against the other tied teams, the determining factor is BCS rank.
That would seem to favor OU and OSU, since they lost earlier (both to Texas in October) and would have won two huge games (Tech and Bedlam) in November.