In their past five games, the Dallas Cowboys have only periodically played with the sort of efficiency that has made them the favorite team of key punch operators everywhere.

A pallid 21-7 victory over the New Orleans Saints was followed by losses to the Philadelphia Eagles and the Minnesota Vikings. Against two of the Super Bowl tournament's lesser teams, the Tampa Bay Buccaneers and the Green Bay Packers, the Cowboys required big fourth-quarter plays to advance to Saturday's NFC championship game against the Redskins.

Coach Tom Landry's humility after Sunday's game was well-founded.

"We made some errors and they did too. But we made the plays we had to," he said.

Although the Cowboys came up with enough clutch plays to win, including Drew Pearson's 49-yard pass to Tony Hill and Dennis Thurman's 39-yard interception return for a touchdown, Landry could not hide the fact that his players were given to mistakes and fallability.

In a playoff game. Against a very young 5-3-1 team.

Tony Dorsett said the Cowboys need "a killer instinct." That need was obvious in the first quarter Sunday when the Cowboys had a chance to rout the Packers in the first 10 minutes and failed to do so.

Dallas twice had opportunities to score touchdowns before the Packers ran a play from scrimmage, thanks to a fumbled kickoff return by Del Rodgers, but settled for field goals each time and a 6-0 lead. So instead of facing a 14-0 deficit, the Packers were able to overcome their shoddy first quarter, in which they ran only eight plays from scrimmage, and make the game competitive.

Against the Redskins, a decidedly tougher, more experienced team than either the Buccaneers or the Packers, the Cowboys may have more difficulty making up for squandered opportunities.

For the third year in a row, Dallas is playing on the road for the NFC championship. Last season the Cowboys lost to the San Francisco 49ers, 28-27, and the year before to the Philadelphia Eagles, 20-7.

It was 54 degrees and sunny at Texas Stadium in Irving Sunday. Both the weather and the Washington fans will feel decidedly cooler to the Cowboys.

"The field will be an advantage for Washington," said Landry. "It's always heavy, and if it's wet they will just give the ball to (John) Riggins 40 times and dare you to stop them."

The Packers, who relied mainly on Lynn Dickey's passes for their offense, were effective the few times they ran the ball.

The Dallas defense was most effective when it blitzed. Only in the second half did the Packers effectively counter the blitz with screen passes.

Although the Cowboys handed the Redskins their only loss of this truncated season, most Dallas players are reluctant to betray more than a trace of confidence before the rematch.

"It's important to quiet down the crowd early," said running back Timmy Newsome. "I don't think there's that much advantage in having beaten them already. Washington is playing extremely well right now."

Rafael Septien, whose 14 straight playoff field goals are an unofficial NFL record, was one of the few Cowboys willing to fire an early salvo. He aimed right for his rival kicker, Mark Moseley.

"He's lucky," Septien said of Moseley's NFL record for consecutive field goals, established over the last two seasons. "He's had a lucky season, a lot of short field goals this year. Now he's probably not mentally ready."

The Cowboys played without defensive tackle John Dutton (bruised thigh) and fullback Ron Springs (sprained right knee) against the Packers. Afterward Landry said Springs probably will play against the Redskins, but that Dutton was still questionable. Backup running back James Jones (injured left knee) is also questionable.