West: No. 2 Oklahoma vs. No. 3 Arizona

The story line: No one expected Arizona to be here after the Wildcats lost four starters off last season’s nation runner-up. But coach Lute Olson has received great play from his freshmen, and holdovers Luke Walton and Jason Gardner have been steady all season. Oklahoma plays lockdown defense, can run when it has to and hits the boards. Sooners senior forward Aaron McGhee is going to be a huge matchup problem for the Wildcats.

The “X” factor: Arizona freshman guard Salim Stoudamire has great range and will need to hit some three-pointers to loosen up OU’s defense. Arizona has good athletes who can run with the Sooners. The key for Arizona is outside shooting.