American football is an up-market, billion dollar business. The teams are run like movie studios, they are awash with talent and glamour and no team has more glamour than the San Francisco 49ers, winners of two Superbowls and one of America's top teams. Clive James spends a week with the 49ers - he meets the players off the field, spends some time with the cheerleaders and enjoys a new experience 2,000 feet above San Francisco Bay.