CHICAGO - The math always comes out the same. If the Flyers were going to win the Stanley Cup, they were always going to have to win at least one game in the red-lit crucible that is the United Center.

After two losses here, that seemed very possible. After this one, a 7-4 ambush in Game 5 Sunday night, a Flyers win here is much tougher to imagine.

They are going to have to earn the opportunity, of course. The Stanley Cup itself will be in the Wachovia Center on Wednesday night for Game 6. The Flyers' mission is to keep the big silver beast in its case. Win one at home and it all comes down to Game 7 Friday night.

Here. In Chicago.

Here in Chicago, where the Flyers have twice gotten caught up in freewheeling, high-scoring games of the kind they simply can't afford to play against the Blackhawks. Here in Chicago, where twice in three games Peter Laviolette has been forced to pull his starting goaltender.

After Game 1, which the Flyers lost 6-5, it seemed automatic that Laviolette would come back with Michael Leighton in Game 2. The Flyers' defense was awful that night. Leighton's crime was being less than great in the face of the onslaught. Sure enough, Leighton returned to the net and was very good.

This time, it's a little less certain. Leighton looked strong early in a first-period feeding frenzy, then he fell apart. None of the three goals he allowed resulted from especially impressive Chicago plays.

Leighton gave Brent Seabrook a huge target on the first goal. The second was simply a mental lapse by the goalie. He failed to seal off the post and allowed Dave Bolland to bank the puck in off the back of his skate. The third, by Kris Versteeg, was a shot in the high slot that simply has to be stopped in the Stanley Cup Finals.

Laviolette clearly felt the same way. Brian Boucher came into the game to start the second period.

It's a tough call. Leighton has played well after poor games throughout the postseason. He is also undefeated at home. Boucher was in goal for the Flyers' lone loss at the Wachovia Center, to Boston, but he played fairly well.

Boucher had an opportunity to make a case for himself, to convince Laviolette to let him play a game from the opening face-off. He didn't exactly succeed, surrendering three goals - including a back-breaker on a clean shot by Patrick Sharp in the third period.

It is a pretty safe bet that Laviolette had a little chat with his players after that hideous first period. The coach came out to the bench all by himself, much earlier than usual. You could almost see the steam coming out of his ears all the way from the press box.

Laviolette also had a long talk with the two referees as they emerged for the second period. That may have been his only reason for leaving the locker room early.

Odd as it sounds, given the 3-0 hole they were in, the Flyers really lost the game in the second period. Remember, this team fell behind 3-0 in Game 7 against Boston and just kept coming, erasing the deficit and winning, 4-3.

Once again, there was no quit in the Flyers. They beat Chicago goalie Antti Niemi at least five times in the second period. Trouble is, they only scored two goals. There were a few missed opportunities that will haunt this team for a long time if this ends with the Blackhawks raising the Cup.

Blair Betts fanned on a rebound in the slot with Niemi down. A few moments later, Patrick Kane slipped behind Danny Briere and converted a slick pass from Andrew Ladd.

Later, on the same power play, Mike Richards and Ville Leino missed wide-open nets. Richards tried to be too fine on a crossing pass from Simon Gagne and pushed it into the pad of the desperately sliding Niemi. Then Richards made a great pass to Leino in nearly the same spot. Leino did what Richards tried to avoid, rushing a shot that went wide.

A few minutes later, with Chris Pronger in the penalty box, his nemesis Dustin Byfuglien scored exactly the kind of point-blank goal the Flyers had denied him for four games.

The Flyers missed their chances. The Blackhawks did not.

Home ice, which was almost meaningless through the first three rounds in both conferences, has meant everything through five games in the Finals.

The Flyers have to make it count one more time, then they have to find a way to get that one elusive win in Chicago.

That seemed a whole lot more likely before the horror show that was Game 5.