If Texas wins, then they go to the Big XII title game and face the first (listed) of Oklahoma State, Oklahoma, and Kansas State to win this weekend.

If Texas loses to Texas Tech and only one of the other three listed teams wins, then it's Texas vs. that team.

It's if Texas loses and two or more of the three win -- things get... messy.

A head-to-head sweep, the conference has clarified, trumps "all plays all". It's how Oklahoma State has the first in line in the three-team scenario.

So, if Texas loses:

Kansas State and Oklahoma State win, Oklahoma loses: Texas vs. Oklahoma State: Kansas State swept by the other two teams (I would assume it would also work in this direction).

Oklahoma State and Oklahoma win, Kansas State loses: Next-highest (Oklahoma 1-1 with the other two, Texas and Oklahoma State did not play), and have fun finding it:

Kansas State did not play Oklahoma.
West Virginia did not play Oklahoma or Texas.
Texas Tech did not play Oklahoma or Oklahoma State.
Iowa State would be the team, and the game would be Texas vs. Oklahoma -- they both beat Iowa State, Oklahoma State lost.

Oklahoma and Kansas State win, Oklahoma State loses: Next-highest (with now Texas being the 1-1 and Oklahoma and Kansas State not playing Oklahoma).

If Oklahoma State had played Texas, this probably becomes much easier.
West Virginia did not play Texas either.
In this scenario, all three teams would beat Iowa State.
Texas Tech did not play Oklahoma State.
Kansas beat Oklahoma, but lost to the other two, so the game would be Oklahoma State vs. Kansas State.

All three win: Oklahoma would be first out because Kansas is the highest team (regardless of what Kansas does this week) to face all four other teams.. Kansas beat Oklahoma, lost to the other three. So you now default to the "Oklahoma loses" scenario, Texas vs. Oklahoma State.

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There is one final scenario.

What happens if Oklahoma, Kansas State, and Oklahoma State all lose?

First off, Texas would be in the B12 Championship Game regardless of their result.

The problem is you'd now have a tiebreaker, for one spot, of Oklahoma, Kansas State, Oklahoma State, and AT LEAST Iowa State, with Texas Tech in the tiebreaker too if they beat Texas.

You need to find a common opponent outside the tiebreaker of all the teams in it.

West Virginia did not play Kansas State.
Iowa State and Oklahoma would be the first teams eliminated, because Kansas beat them and lost to Kansas State (and Texas Tech).
Since Kansas State beat Texas Tech, it doesn't matter if Tech is in the tiebreaker or not: Texas vs. Kansas State.

Mike