Lines are set based on projected outcome and projected betting. Except in rare cases, the lines are set to get balanced action. The line typically moves based on the fact that actual betting is different than the expected betting. The lines can be taken down because of uncertainty surrounding injuries, especially to quarterbacks. In this game the injury situation with Martinez, Lee and Murray is enough to affect this. The likely explanation for the line shift in this game is that many bettors believe in the conspiracy, not "Vegas". Therefore more money than anticipated is being placed on OU, thus driving the line upward from where it started, making a bet on NU more attractive. This is an attempt by "Vegas" to get more money on NU. To be clear, when we say Vegas we are speaking of the guys in the back rooms who set the lines for the sportsbooks, right?