Letdowns are uncommon in college hoops, what with playing dates usually spaced out. But one looms here. Ohio State ambushed Purdue on the road Wednesday and returns home as a lopsided favorite. The Buckeyes better wear their running shows since the Hawkeyes score at the highest rate in the Big Ten. Iowa feels good about itself after taking Michigan State to the wire four days ago in a three-point defeat. Euphoria over OSU's upset of the Boilermakers has pushed the line two points from 12.5, which opens the door wider to a possible spread win by the underdog.