A ball is said to be driven to a rail if it is not touching that rail and then touches that rail. A ball touching at the start of a shot (said to be “frozen” to the rail) is not considered driven to that rail unless it leaves the rail and returns. A ball that is pocketed or driven off the table is also considered to have been driven to a rail. A ball is assumed not to be frozen to any rail unless it is declared frozen by the referee, the shooter, or the opponent. See also Regulation 27, Calling Frozen Balls.
