Colorado will try to stay in the hunt for the Big-12 north division championship with a visit to Iowa State. Colorado coach Gary Barnett says the key for the Buffaloes defense will be slowing down Cyclone quarterback Seneca Wallace.Barnett says with Wallace at quarterback, the Cyclones are trying to get outside the ends more often. He says the option and shotgun offense have been used to take advantage of Wallace’s speed.Barnett says it has also opened up the passing game.