The most important statistic in figuring the Redskins-Lions game is the interception rate, according to a computer-aided analysis.

While this is generally true in all games, it is especially important in today's game because Detroit's defense is the NFL's weakest (stealing only six passes in 10 games); Joe Theismann has thrown only eight interceptions (ranking second).

When the electronic hardware scans the 224 games of the 1983 season, it finds that the unit value of one interception is 5.5 points in the winning margin. For example, if the Redskins intercept one pass and the Lions none, that should make almost a touchdown difference in Washington's favor.

In addition, the Lions' defense this season has been the easiest to move the ball on. It allows 2.3 passing touchdowns for each interception (ranking 28th). It has the lowest defensive interception percentage (1.9 percent, or less than one in 50 passes by opponents).

Meanwhile, the Redskins' defense is the league's best in forcing opponents to pass, allowing the smallest ratio of running plays to pass attempts. Without Billy Sims, it is unlikely the Lions will do much on the ground.

Whether John Riggins plays is not the question. The game will be decided in the air. The computer projects a two-interception differential between the two teams in Washington's favor, the basis for an 11-point victory.