A key reason the Flyers have so far held off Pittsburgh in the race for the No. 1 playoff seed in the Eastern Conference is their improved penalty-killing unit.

As fine a season as the Flyers are having, their penalty-killing unit was ranked 17th in the NHL on Jan. 14, which is barely mediocre. Fast-forward a little more than three weeks, and the Flyers have rocketed up to No. 10.

Blair Betts, a fixture on the Flyers' top penalty-killing unit that includes Darroll Powe, Mike Richards, and Claude Giroux, cited three factors in the improvement - more aggressiveness, fewer penalties by the Flyers, and a growing confidence.

"I think we've actually been better at being more aggressive," Betts said Sunday after practice at the Skate Zone. "You know, it's tough to pressure up-ice and not allow them entries into your zone, but when they do dump the puck, they enter our zone, and we've been doing better at pressuring them and not giving them easy plays. And earlier in the year we were taking a lot of penalties, and we've been a lot more disciplined of late. It's made our job easier.

"Looking back over about the last 10 games, I think the only game where we had to kill more than two or three penalties was against Montreal."

In the last 10 games, in which the Flyers are 8-2, they successfully killed 27 of 30 power plays, or 90 percent, which lifted their season percentage to 83.3 percent. Take away the eight power plays they had to deal with against Montreal on Jan. 25, and the Flyers have faced only 22 power plays in the other nine games. That's a good way to preserve energy.

"I don't think anything's changed that much in what we're doing," Flyers coach Peter Laviolette said. "I mean, there are different things you do based on the team you're playing. Against New Jersey, you want to take away Ilya Kovalchuk's backdoor shot.

"But for the most part, penalty killing is about the energy, the execution of your system, and goaltending. And all three of those have been good."

The Flyers finished No. 11 in penalty killing last season, when they advanced to the Stanley Cup Finals. The top unit had to replace penalty-killing ace Ian Laperriere, who hasn't played this season because of post-concussion syndrome. Giroux has capably moved into Laperriere's spot. He and Richards can concern power-play units with their ability to go on the offensive. Each has three shorthanded goals.

"You watch them both, and they can kind of read where the puck's going before it's even going there," Betts said. "Maybe because they're on the power play they can read what the other power play is doing better. But every time the puck turns over, they're looking to create offense. It can be dangerous. Power plays don't expect that too often."

Notes. Defenseman Kimmo Timonen was given the day off. . . . The Flyers' 35 wins are the third-most they've had at this point in the club's history. They had 36 wins after 53 games during 1979-80 and 1985-86. . . . The Flyers are off until Thursday, when they play Carolina at the Wells Fargo Center in the third game of a four-game homestand. . . . The Flyers will not practice Monday.