Teams get moved by seed line, yes, but often to account for conference conflicts. So, obviously teams don't get moved from the 8 line to the 9 line, or vice versa, since that doesn't do anything. Same with 4 to 5 and 2 to 3, which are the only other seed lines that are consecutively expected to be played. 1 seeds are never moved off the 1 seed line (since the whole bracket is built around those 1 seeds). If anything, the gap between a 2 and 3, a 4 and 5, or an 8 and 9 is smaller than it should be as the result of teams moving seed lines. The only team this year which obviously appeared to be moved down a line was Marquette (since there were already 4 BE teams in the 4/5/12/13 bracket in Pitt, UConn, ND and Villanova).