The clock's racing. Two minutes remain. Your team is down by six points with the ball, first- and-10 at its own 20-yard line.

Hang tough. There's still hope and a 15-percent chance your guys will win.

So figure computer science professors Vince Freeh of N.C. State and David Lowenthal of the University of Georgia, who developed what they call the "Victory Forecast" system with some heavy number crunching.

They began by downloading plays -- about 180,000 -- from every NFL regular-season game from 2002 through 2006, then creating an "objective analysis" for predicting what percentage a team has of winning on every down during a game.

Included in the complex formula, which can be applied to college and pro games, are seven key elements -- game score, line of scrimmage, time remaining, down, distance, timeouts for the offense and timeouts for the defense.

Example: Five minutes into Sunday's Cleveland-Baltimore game, the Browns had the ball, third-and-goal at the Ravens' 2-yard line. At that moment, Cleveland had a 69 percent chance of winning, Baltimore a 31 percent chance.

The Browns won, 27-13.

"What we try not to do and can not do is measure intangibles," said Freeh, a longtime fan who played high school football in Ohio and Arizona.

Injuries, emotion and teams' strengths and weaknesses don't factor into the formula. It's "average" team vs. "average" team, Freeh said.

Thus, the probability of a highly favored team winning wouldn't be any greater than a lesser opponent's, given the same situation.

Here are examples from Sunday's Green Bay-Minnesota matchup.

* 13:11 left in the first quarter. No score. Minnesota has possession, second-and-4 at its own 39, and a 55 percent chance to win.

* 11:46 left in the fourth quarter. Minnesota, trailing 16-9, faces a third-and-19 at its own 43 with a 23 percent chance of winning. Green Bay had a 77 percent chance to win in that situation.

The Packers won 23-16 as Brett Favre threw for two touchdowns and set the NFL career record for touchdown passes.

Freeh and Lowenthal, who have broken down college games since 2004, also write Victory Forecast-related stories for the New England Patriots Newsletter. But they hope to do more.

"We would like to get a large presence on a Web site for fans," Freeh said.

But the ultimate goal, Freeh added, would be to sell the probability percentages to coaches, who might find their information valuable in certain decision-making situations. He cited a scenario in Monday night's New England-Cincinnati game.

"Cincinnati was down 17 points in the fourth quarter, fourth-and-2, and kicked a field goal," Freeh said. "That was a very makeable situation. It was a bad idea to go for a field goal. A field goal increased their chances of winning by 6 percent. A touchdown would have almost doubled their chances, to 11 percent."