Pull out the computer floppy disc and the midnight oil. Entering this final four-day weekend of the National Football League season, 13 of 28 teams still had playoff hopes.

The time has come for more than just the elemental football arts of blocking and tackling. How about tie breaking, too?

Curtis Jordan, the irreverent Texan and Washington Redskins safety, figures, "The tie-breaker system isn't meant for football players to figure out. I hired a computer whiz to do it for me. I mean you gotta figure right down to if Herndon High scores six points in the fourth quarter this week, they are in."

Sifting through the numbers, this much we can say for sure:

*Three teams are competing for two wild-card berths in the National Football Conference: the New York Giants, San Francisco 49ers and the Redskins. If all three teams win, the Redskins are out and the 49ers will play the Giants in the wild-card game next Sunday at Giants Stadium.

If the Redskins win and either the Giants or 49ers lose, the Redskins will earn a wild-card berth and will have completed a remarkable rescue job on a season that began 1-3.

*Three teams also are competing for two wild-card berths in the American Football Conference: the New England Patriots, the New York Jets and the Denver Broncos, who defeated the Seattle Seahawks, 27-24, last night. If the other two teams lose Sunday, the Broncos and Jets advance. However, if the other two teams win, gone from the playoffs are the Broncos. The Jets and Patriots, both in the AFC East, then would meet for the third time this season, in the wild-card game in the Meadowlands.

*Only one division title has yet to be won outright, the AFC Central, where Cleveland (8-7) leads Cincinnati (7-8) and Pittsburgh (7-8) by a game. The Steelers already have been eliminated because of inferior records in games against division opponents.

Consequently, if the Browns defeat the Jets Sunday, the division title is theirs. But if the Browns lose and the Bengals win, Cincinnati is in the playoffs and the Browns are out. Bye-bye, Bernie; bring on Boomer.

*If you're looking way down the playoff highway, you'll see that the Los Angeles Raiders' (11-4) game against the Los Angeles Rams (11-4) Monday night in Anaheim, Calif., carries great significance for the Raiders.

If the Raiders win, they will have the home-field advantage throughout the AFC playoffs. If Miami (11-4, playing Buffalo Sunday) and the Raiders both finish 12-4, the Raiders will have the home-field advantage if both advance to the conference title game on Jan. 12.

The Raiders would claim that advantage over Miami by virtue of a better record against common opponents (5-1 to Miami's 4-2).

The Orange Bowl has been an ambush zone for Dolphins opponents, where Miami has won more than 80 percent of its game since 1970.

*The Bears (14-1) are sitting just princely, thank you. The temperature continues to drop these days in Chicago. The wind chill, meanwhile, warms Bears hearts.

After all, the reasoning goes, sub-zero temperatures damage a passing offense and turn a game into a struggle made for defense and a rushing offense.

These are the Bears' strongest suits. They have allowed a league-low 181 points this season and San Francisco (247 points allowed) has the only defense within a 10-touchdown yield of that figure. Furthermore, on offense the Bears average a league-best 173 yards rushing per game.

*Cincinnati, Denver and Washington were the only teams still with a chance to reach the playoffs that could win and still not advance to the 10-team postseason.

"If that's what happens, we don't have anybody to blame but ourselves," said Jordan. "We've had the opportunities. It's a fair system. If you eliminate the division races, I think you really take away from the fan interest."

It is ironic that, with all of the playoff possibilties, the two wild-card games could be played in the same location: Giants Stadium. It's possible that the Giants and Jets, who play their home games at Giants Stadium, will play host to wild-card games.

A spokesman at the league office said yesterday that if such a situation arises, one of the games will be played next Saturday, instead of both games being played Sunday.