Oakland's talent at other skilled positions would be wasted but for the coolness under a rush and the left-handed accuracy of Quarterback Ken (Snake) Stabler. "It's essential that we have a guy in that position who can deliver the ball," says Coach John Madden. "And that's what Kenny does better than anyone else. He moves the ball. Our offense all begins with Stabler." Hobbled by a bad knee last season. Stabler still completed 58.4% of his passes for 2,296 yards and 16 touchdowns. The NFL's best conductor of the two-minute drill. Stabler is the player Oakland can least afford to lose. "The difference between Stabler and his backup," says one coach, "is the difference between an ace and a deuce."