Roundtable: Here's who will be the X factor in Maple Leafs-Bruins Game 7 -- and who will win

Who or what will be the X Factor in Game 7 of the Toronto Maple Leafs-Boston Bruins Series?

Greg Wyshynski, senior NHL writer: Boston's Patrice Bergeron line. The numbers for Bergeron, David Pastrnak and Brad Marchand remain obscenely good for the series: a plus-45 in shot attempts against the Maple Leafs. But they're now just a plus-1 in goals at 5-on-5 after looking like they were going to carry the Bruins to victory in the first two games in Boston. Pastrnak has two assists in four games and has scored in his past two. Marchand has one goal in his past four is and scoreless in his past two. Bergeron is scoreless in three and missed Game 4 because of injury. Boston needs the best line in hockey to be the best line in Game 7.

Emily Kaplan, national NHL reporter: Despite blowing the early series lead, the deeper and more talented Bruins are still the favorite. For the Maple Leafs to have any chance at the upset, Frederik Andersen is going to need to play out of his mind. The good news for Toronto: The 28-year-old has been terrific of late. After a rocky start, Andersen has a .936 save percentage over his past four games, including 32 saves in Monday's Game 6. He has consistently been a leading figure in this series. When he has been off his game, Toronto has been blown out. When he's on -- well, there's a reason we're now at a Game 7.

Chris Peters, NHL prospects writer: No active NHL player has appeared in a Game 7 more times than Zdeno Chara. Wednesday night will mark the 12th Game 7 of his career, one shy of the record co-held by Hockey Hall of Famers Patrick Roy and Scott Stevens. Chara's teams are 4-7 in those games, and the big defenseman has three points, all assists. Experience matters, and Chara's performance in the series to date has been solid as he has seen a lot of Auston Matthews so far. The Bruins are outscoring the Maple Leafs 6-1 when Chara is on the ice against Matthews at 5-on-5. With Boston owning the last change and Matthews showing some signs of heating up, this matchup becomes all the more important. So I'll go with the veteran captain, who has seen all you can see in these situations, to come up big on home ice.

Ben Arledge, NHL Insider editor: I'm going to agree with Emily here: Andersen's level of play is the biggest variable in Game 7, especially at TD Garden. In Toronto's three wins, he has posted save percentages of .970, .952 and .933. In the three losses -- two of which came on the road -- those numbers have been .875, .857 and .400 (three goals on five shots before being pulled in Game 2).

The Maple Leafs have an average group of defensemen, and against this top-tier Boston offense, Andersen has been leaned on heavily on the back end. Look for Rick Nash and Marchand to create some chaos in front of the net, and expect a heavy dose of rubber off the stick of Pastrnak once again -- he leads the team with 24 shots in the playoffs. But there is little doubt this game hinges on just how well Andersen can perform.

Who will win?

Wyshynski: I originally picked the Maple Leafs to win in six. I'll pick them to win in seven instead, as I feel like they've found their footing against the Bruins. As long as they get the dominant Freddie Andersen and not the soft-goal Freddie Andersen.

Kaplan: The Bruins. Bergeron, Marchand and Pastrnak put a ton of pressure on Andersen in Game 6; they just didn't get the results. I see Boston's big names breaking through, as one of them will play hero at home.

Peters: I have been so hot and cold on the Maple Leafs all series. I picked them in seven before this roller coaster started. I have admired their pushback and thought their overall performance in Game 6 was impressive. I also think I have continually underestimated the Bruins. The experience factor is a big one, especially in this specific situation. With home ice on their side, my brain is telling me it's Boston. My pre-series pick, however, is telling me, "no takebacks."

Arledge: My original prediction was Toronto in seven games, so I'm married to it at this point. The Leafs roll in with some momentum, and I feel another quality outing coming from Andersen. Even though they'll be on the road in a loud building, I'll stick with the Maple Leafs to complete the comeback.