starting quarterbacks, if they remain healthy for the entire schedule, are not unusual. Backfield motion Perhaps the greatest difference arises due to the virtually unlimited movement allowed in the defensive and offensive backfields on a play from scrimmage in the Canadian game vs. very restricted offensive movement in the American game. Combined with the much larger field size, this difference changes the skillsets required of the athletes. Canadian wide receivers, safeties and cornerbacks are far enough from the point where the ball is snapped that they rarely participate in rush offense or defense. Linebackers can be called upon to successfully defend running backs sent to receive passes. There is therefore a much greater premium placed on athletic speed, with former Edmonton Eskimos GM and former wide receiver Ed Hervey (, , All-American at USC in the 200 meter) and Malcolm Frank ( ) being prototypical for the CFL. The offence has many more formation options and starting positions, forcing the defence to anticipate more possibilities. Seven of the 12 men on a CFL offense (typically the five linemen and the wide receivers) must be at the line of scrimmage at the time of the snap, and the other five must be at least one yard behind the line. Only the quarterback and linemen must be motionless at the time of the snap, allowing up to six players to be moving toward or along the line at varying speeds (typically the wide receivers are still or at a walking pace at the snap to ensure they are at the line of scrimmage.) Late comebacks In both the college and pro games, an offensive team with the lead has more difficulty in running out the clock in the Canadian game. In the Canadian Football League, the clock is stopped while the officials place the ball, and then they whistle the game clock and play clock to begin in the last minutes of a half; whereas in the National Football League the clock remains running while the officials set the ball (dependent upon the result of the previous play—penalty, incomplete pass, out-of-bounds, or tackle inbounds in both leagues) while the play clock of 40 seconds runs down. The game clock only begins again when the play is whistled in, for an inbounds tackle, or at the snap of the ball for the other outcomes in the CFL. A team that is ahead has