Vegas doesn't set the line...Danny Sheridan does!
Vegas might open it, but Danny Sheridan sets it. the line opened at -1 for Michigan at most places...but as soon as Sheridan's line came out in the USA Today it shot up to -2-5 for Michigan and has stayed there basically...hovering between 2.5 and 3
Look at almost all lines, they always mimic Sheridan's line as soon as it comes out.
Does this mean Sheridan's line is better (maybe or maybe not) it definitely means Vegas is smart enough to know that the USA Today has a ton of subscribers and they seem to keep the line right around Sheridan's number at all times!