That second player doesn’t even have to be a linebacker. Alabama, which has won three national championships in four years and boasts the best defense in college football, constantly varies the defenders assigned to the quarterback. When Alabama defensive coordinator Kirby Smart gives a “force” call, he explains, that leads to a gap replacement with the defensive end. “The quarterback sees the crashing end and pulls the ball,” Smart says. “We roll the free safety down to the line of scrimmage and he has the quarterback.” And all this varies based on the opponent. “If the quarterback is a better runner, we make him give to the tailback,” said Smart. “If the tailback is the better runner, we give the force call, and the defensive end crashes inside and makes the quarterback pull the ball.”