steam is a word invented by don best and other services.
oddsmakers who make lines for the major books are not the
only ones to do this. syndicates or individuals pay statiticians, mathemticians, etc, alot of money to put out a line using their programs;
and when unknowing to each other a group of these paid genius' working for the same individual or group come out with the same number, and it is a certain deviation from the books' number, the wise guys play. now the line will move and the services like don best alert their customers to the move which they call "steam"