Line for at max 16 games
For college they need to create 100 different openers and power ratings in college vary drastically from week to week with 1 player going down, weather etc.
If you say that the originators miss on 5% of their opening numbers, there are more opportunities for Billy Walters and gang to pound wrong opening numbers in college
Very few NFL games will the line move more than 2 pts after opening unless their is an injury announced. Partly because of the time devoted to NFL lines compared to NCAA lines, but also because of the amount of money coming in on an NFL games is so much higher than your average college game, that it is harder to move the number.