PIEDMONT, Calif.  After the 2006 season at Piedmont High, Coach Kurt Bryan and an assistant sat around with a dry erase board, trying to coax a Ouija board’s connection with football’s innovative spirits. Their aim was to keep this Bay Area school, with a small enrollment (785 students) and generally small but athletic players, competitive against bigger schools with bigger players.

Steve Humphries, the assistant, had an idea: What if the offense featured not one quarterback but two? Not bad, Bryan said, but things would really get interesting if all 11 players were potentially eligible to receive a pass.

Hence, the A-11 offense was born.

To its proponents, the A-11 represents the logical and inevitable evolution of a game that is becoming faster and more spread out at all levels. The alignment diminishes, or eliminates, the need for a traditional offensive line, where players can weigh 300 pounds even in high school. And, coaches say, it reduces injury because it involves glancing blows more than smash-mouth collisions.

To its detractors, the A-11 is a gimmick that cleverly but unfairly takes advantage of a loophole in the rules. To these critics, the offense places an inequitable burden on defenses to determine who is eligible for passes and makes the sport nearly impossible to referee.