Because of the dominance of passing thses days, TOP isn't as important a measure as it used to be. Clemson is low in TOP because they throw the ball so much and the clock stops after every incompletion. What TOP tells you is which team is better at running the football. Run dominant teams like Wisconsin, Army and Navy dominate time of possesion because they run the ball so much. Dominating TOP does reduce the number of possessions of the both teams and allows your own D to defend fewer plays.