My guess is Carr probably won't get #1 seed in almost any scenerio.
If he beats O'Toole, and Messenbrink goes undefeated, Messenbrink will get #1 seed and Carr get the #2 seed.
If O'Toole wins Big 12's, O'Toole gets #1 and Messenbrink gets #2 and Carr #3.
Only chance of Carr getting #1 is...