It's a cliché in football that every fan thinks he's a coach. Now there's a computer that thinks it's a coach.

Indiana University scientist Chuck Bower and two partners have created ZEUS, a computer model of football as the game is played in the National Football League. ZEUS is based on years of NFL statistics and runs on an off-the-shelf laptop, perfect for a football sideline or a coach's booth above the playing field.

ZEUS is designed to do what a coach needs to do during a game but can't -- calculate the consequences of a decision before he calls the next play. Accept the penalty or decline it? Go for it on fourth down or punt? Go for one extra point or two after the touchdown?

These are the kinds of decisions that often determine the outcome of a game, especially a close one. In many situations the decision is obvious, but sometimes it's not clear which choice offers the best chance to win. That's where ZEUS comes in.

Bower emphasizes that ZEUS is not a substitute for coaching skills, but “a valuable addition to a coaching staff's tools” that can provide “that elusive edge over the competition. ZEUS is “powerful enough to simulate the equivalent of every game played in the history of the NFL in less than a second,” says Bower. “It can objectively assess crucial play-calling decisions with startling accuracy."

Another application of ZEUS involves "player position value." With the help of NFL data that are conversions of individual player performance into usable statistical input, “ZEUS can convert a player's performance to net wins per season," Bower says. "This is a great aid to NFL managers who must work within a team salary cap."

Information about ZEUS is available at www.pigskinrevolution.com/index.html . The current NFL season is being followed at www.pigskinrevolution.com/services2.html . For example, ZEUS's analysis of three crucial situations in a recent game between the Indianapolis Colts and the New York Jets can be found here: www.pigskinrevolution.com/colts_jets_week4_06.html .

The remarkably close correlation between ZEUS analysis and the best available NFL historical data is shown at www.pigskinrevolution.com/palmerslide.html .

Bower and his colleagues built ZEUS using extensive research into NFL game logs, historical statistics, and the behavioral traits of coaches. The core model replicates the play-calling and statistical outputs of typical NFL teams, Bower says. ZEUS can also be customized for the offense and defense of a particular NFL team and its opponent. Then, with the capability of performing more than a million game simulations in a matter of seconds, it can assess critical play choices on their relative merits.

"There is simply not a more accurate way to assess a critical play-calling decision in football," Bower says.