PITTSBURGH - The Pittsburgh Steelers still haven't lost since Tommy Maddox was their quarterback. That doesn't mean they look as unstoppable, or as unbeatable, as they did when they dismantled New England and Philadelphia in consecutive weeks.

Ben Roethlisberger is playing more like a rookie, rather than the greatest quarterback to come along since Dan Marino or Peyton Manning. The offensive line, so in control all season, is yielding sacks - 11 in two games. And the offense has become ever dependent on its oldest component, running back Jerome Bettis.

The Steelers (10-1) are unbeaten since Week 2 and own their best 11-game record since 1975, but they hardly have reason to relax as the season winds down. The nearly locked up - they lead Baltimore (7-4) by three games with five to play - but they are still positioning themselves now for the all-important playoff seeding.

Though the Steelers currently hold the edge over the New England Patriots (10-1) for home-field advantage throughout the AFC playoffs, one slip-up or badly played game between now and Jan. 2 could change that. Lose the home-field edge, and they might have to beat a quality opponent such as the Colts (8-3) just for the right to play at New England in the AFC Championship game.

Their remaining five games - Jacksonville (6-5), New York Jets (8-3), New York Giants (5-6), Baltimore (7-4) and Buffalo (5-6) - look far more challenging than the last three, and none of those games was easy.

They managed to beat losing-record Cleveland (24-10), Cincinnati (19-14) and Washington (16-7), but their offense scored only four touchdowns in the three games - just one in each of the last two games. That offense produced only 10 points against the Bengals a week before the Browns lit them up for 48 points.

Now, with three winning-record teams left to play plus the Giants and improving Bills on the road, the Steelers realize they must raise their level of play even while they are on one of the three longest winning streaks in franchise history.

Their nine-game streak equals that at the end of 1976, and is two short of the team-record 11 in a row in 1975 - the second of their four Super Bowl-winning teams.

"This (five-game stretch) is going to determine our season," said Bettis, who has four consecutive 100-yard game while subbing for the injured Duce Staley. "We have a tremendous test ahead of us. We have to get better. We are not playing tremendously great. Offensively, we are doing enough to get it done, so we have to play better and we understand that."

Maybe the Steelers have only themselves to blame after creating enormous expectations by handling the Patriots (34-20) and Eagles (27-3) as easily as they did.

"What you have to expect is to be consistent and go out there and complete passes and get positive yardage plays," Bettis said. "We have been having too many minus-to-zero yard plays, and that is not the way we do things around here."

The Steelers didn't gain or lost yardage on 26 of 62 plays against Washington, including four plays while running out the clock. The week before, they failed to gain or lost yardage on 21 of 68 plays in Cincinnati, including seven sacks of Roethlisberger.

That's a two-week total of lost or no yardage on 47 of 130 plays - nearly 40 percent, much too high a percentage for a team that, based on its excellent start, will be satisfied with nothing less than the Super Bowl.

One reason is that Roethlisberger has cooled off, even as he remains unbeaten in the NFL. He hasn't thrown for a touchdown in two of his last three games or passed for more than 138 yards since the Eagles game on Nov. 7.

The offense figures to improve in Jacksonville, when wide receiver Plaxico Burress (hamstring) and Staley (hamstring) expect to return.

"Ten-and-one? It's lovely. It speaks for itself," linebacker Clark Haggans said. "But we can get a lot better."