Last season the records fell like saplings in a hurricane, but Francis Asbury Tarkenton pays little notice to records. Up to now he has attempted more passes (5,225), completed more (2,931) and thrown for more touchdowns (291) than any quarterback in history. Who cares? Tarkenton insists he plays the game only because it's fun, and, of course, because the game pays him about $300,000 a year. "I'm still learning," he says. "I never find myself unchallenged." Tarkenton has not been blessed with exceptional receivers in Minnesota so he has made a living by throwing to his backs. "I take what the defense gives me," he says. "I never had the arm to throw long anyway." With respect for his age and health, Tarkenton seldom scrambles these days (only 16 times last season compared to his career average of 42), but he still scurries around long enough for his secondary receivers to get free. He will be at the Super Bowl in Pasadena on Jan. 9. As a player. Or as a commentator for NBC. Or maybe both.