5 Keys: Bruins at Maple Leafs, Game 6

BRUINS at MAPLE LEAFS
Sunday, 3 p.m. ET; NBC, CBC, SN, TVAS
Maple Leafs lead best-of-7 series 3-2
The Toronto Maple Leafs can win their first Stanley Cup Playoff series since 2004 by defeating the Boston Bruins in Game 6 of the best-of-7 Eastern Conference First Round at Scotiabank Arena on Sunday.

RELATED: [Complete Bruins vs. Maple Leafs series coverage]
The teams have alternated victories in the series, with the Maple Leafs winning Games 1, 3 and 5.
Here are 5 keys for Game 6:

1. Bruins power play, Maple Leafs penalty kill

The Bruins power play scored in each of the first four games, going 5-for-11. Toronto coach Mike Babcock was visibly frustrated when its penalty kill allowed a goal on each of its two shorthanded situations in a 6-4 loss in Game 4 and vowed to fix things.
Lesson learned. Boston's power play went 0-for-3 in a 2-1 loss in Game 5. All those opportunities came with the score 0-0, when a power-play goal would have changed the momentum.

2. Boston needs more offense

The Bruins lamented their lack of quality scoring chances in the Game 5 loss. Simply put, they need far more secondary scoring than they've been getting. Charlie Coyle (two) and David Krejci (two) are the only Boston players on the bottom three lines who have scored more than one goal. Boston's No. 1 line from the regular season -- Patrice Bergeron, Brad Marchand, David Pastrnak -- have two goals each but will face tight checking from Toronto.
Boston coach Bruce Cassidy put Pastrnak on the second line to counter that in Game 4, and Pastrnak scored his two goals. Toronto coach Mike Babcock will have the last line change and likely will counter with the 1-2 center punch of John Tavares and Auston Matthews for defensive purposes.

3. Boston's forecheck

The Bruins' forecheck caused problems for the Maple Leafs in a 4-1, Game 2 win, forcing Toronto's defense into turnovers and using their physicality to create loose pucks. But Friday was a different story. Boston forecheckers seemed to be a step slower and never seemed to be able to get in on Toronto defenders on time. The Bruins also took themselves out of passing lanes, often leaving the Maple Leafs with simple exits from the defensive zone. The Maple Leafs were allowed to transition into offense far too easily, in Cassidy's opinion, so expect the Bruins to tweak their forechecking system.

4. Toronto's defense, led by Matthews

Babcock said Matthews played his best 200-foot game in Game 5. The rest of the Maple Leafs weren't bad either. Toronto arguably turned in its top defensive performance of the season because the players bought in to Babcock's urging for having five backcheckers when Boston was threatening offensively. Center William Nylander, for one, was diving near his own blue line to get pucks out of the zone. That's the type of commitment needed to scuttle what will be a desperate Boston push in Game 6.

5. Maple Leafs' killer instinct

History has not been kind to the Maple Leafs in Game 7 at TD Garden, where they lost in 2013 and 2018 after blowing a third-period lead. If Toronto wants to advance for the first time in 15 years, its best odds are to finish Boston on home ice Sunday. If it doesn't, all bets are off heading back to Boston.

Maple Leafs projected lineup

Zach Hyman -- John Tavares -- Mitchell Marner
Andreas Johnsson -- Auston Matthews -- Kasperi Kapanen
Patrick Marleau -- William Nylander -- Connor Brown
Tyler Ennis -- Frederik Gauthier -- Trevor Moore
Morgan Rielly -- Ron Hainsey
Jake Muzzin -- Nikita Zaitsev
Jake Gardiner -- Travis Dermott
Frederik Andersen
Michael Hutchinson
Scratched: Joseph Woll, Garret Sparks, Justin Holl, Nic Petan, Calle Rosen, Martin Marincin, Igor Ozhiganov
Injured: None

Bruins projected lineup

Brad Marchand -- Patrice Bergeron -- David Pastrnak
Jake DeBrusk -- David Krejci -- Marcus Johansson
Danton Heinen -- Charlie Coyle -- Karson Kuhlman
Joakim Nordstrom -- Sean Kuraly -- Chris Wagner
Zdeno Chara -- Charlie McAvoy
Torey Krug -- Brandon Carlo
John Moore -- Matt Grzelcyk
Tuukka Rask
Jaroslav Halak
Scratched: David Backes, Noel Acciari
Injured: Connor Clifton (upper body), Kevan Miller (lower body)

Status report

The Maple Leafs will use the same lineup from Game 5. ... Backes and Acciari could each be a healthy scratch, based on line rushes at Bruins practice Saturday.
NHL.com correspondents Matt Kalman and Dave McCarthy contributed to this report