PHILADELPHIA -- Here are five things to watch for in Game 4 of the Stanley Cup finals Friday night (the Chicago Blackhawks lead the series 2-1 over the Philadelphia Flyers):

1. The top line (again): We are pretty sure Philadelphia cannot win this series without a better effort from its "top" line of Mike Richards, Simon Gagne and Jeff Carter. We know Carter and Gagne aren't 100 percent given foot injuries sustained in the first round, but they have been worse than ineffective through the first three games of this series.

The trio has been guilty of a myriad of turnovers, and their defensive-zone play has been spotty. The three are a combined minus-14 and have not scored an even-strength goal against the Chicago Blackhawks. In the Flyers' 4-3 victory in Game 3, Richards was schooled on the draw by John Madden, setting up a game-tying second-period goal by Brent Sopel.

Flyers coach Peter Laviolette said Friday morning the line had 20 attempts on net in Game 3, and those chances suggest to him the line is still doing good things. "The chances are there. We'll continue with that line," he said.

It's a dilemma for Laviolette because the three represent some of the team's top skilled players and he is loath to break them up.

2. Special teams: So, are the Flyers' special teams that good or are the Blackhawks' special teams that bad? Discuss amongst yourselves. But the bottom line is, the reason this series is as close as it is harkens back to the fact that Chicago has yet to score a power-play goal in the series (0-for-6) and has allowed four power-play goals on 10 opportunities. The Hawks' chances of ending their 49-year Stanley Cup drought will go up exponentially if they can convert on some of their chances on the man advantage and shut down an opportunistic Flyers' power-play unit. If they continue to come up dry and allow the Flyers success, this series is going to get a whole lot more interesting.

3. The third period: Even though the Blackhawks own a 2-1 series lead, they have floundered in the third period of the past two games (they were outshot 15-4 in the final frame in each of those games). That's not good. If it weren't for Antti Niemi's play in Game 2, the Flyers would have the series lead.

Chicago coach Joel Quenneville said he thought Game 2's discrepancy in shots was due to the Hawks' owning a lead in the third. As for Game 3, a 4-3 overtime win for Philadelphia, Quenneville said he thought the fact that the Flyers tied the game 20 seconds after Patrick Kane had given Chicago a 3-2 lead represented a big shift in momentum. Either way, Quenneville agreed his squad needs to be better in the final frame.

The Blackhawks, a team that has been so good at simply wearing other teams down with skill and speed, have looked tired and out of gas by the end of the past two games. They will have to summon up an extra reserve of energy in Game 4 to avoid heading back to Chicago with the series tied 2-2.

4. Pronger, Pronger, Pronger: News flash: Chris Pronger is pretty good. And he plays a lot of minutes. And he'll give you a whack on the back of the legs or a cross-check in the middle of the back just for fun. That's not news, but that too is reality. The Blackhawks figure Pronger is cheating a bit. There's another news flash, since he's been pushing the envelope for years now.

Maybe the subtle complaints will make referees watch more closely (Quenneville said Pronger makes his players take "the long way" into the zone), but we doubt it. Still, the Blackhawks are going to have to find a way to deal with Pronger -- especially Dustin Byfuglien, who is minus-3 with one assist in the series. That means going into the "dirty" areas in front of the net no matter what, something the Hawks haven't necessarily done a lot of so far in this series.

5. Line tweaks? A couple of possible lineup changes would reflect more tinkering than overhauling for both teams Friday night. Andrew Ladd, who was injured in the final game of the Western Conference finals, could make his first appearance in the Cup finals. He's been skating, but Quenneville said Ladd would be a game-time decision. If Ladd can go, Tomas Kopecky or Adam Burish would be the likely candidates to come out.

Also, it's possible that Flyers winger James van Riemsdyk, a healthy scratch in Game 3, could be back in the lineup, with Daniel Carcillo returning to the press box, as Laviolette tries to balance the tradeoff of adding Riemsdyk's skill against losing Carcillo's toughness. Andreas Nodl could also be an option if Carcillo comes out of the lineup.