jateeluv:
It implies a number of factors, but I'll try to put it simple; so, as a hypothetical example:
Let's say you take X-Team laying 3½, and 3 seconds later the DB screen goes black, reflecting a move towards -4. Having laid 3½ seconds before the move, is called "steam".
The most important question would be: Who creates these moves?
BTW,
I'd like to add BlueGrass to the list of shops with balls.