BOSTON—The Chicago Blackhawks' entire strategy for victory is predicated on a single simple aim: maintaining possession of the puck. They will have it; the other team will not.

Only a select few clubs in the National Hockey League play this way—only a select few can play this way—and none is better at it than the Blackhawks. They led the NHL with 77 points during the regular season. It took them 25 games before they lost in regulation. When they keep the puck, Chicago's forwards and defensemen—a group as deep and as talented as any in the National Hockey League—can weave around the rink until they leave their opponents dizzy, spinning in place.

Daniel Paille's shot finds the net, and the Bruins have all the goals they will need. Getty Images

That is what happens when the Blackhawks are at their best. Nothing like that happened Monday night in Game 3 of the Stanley Cup Finals, for they are facing a team that seems designed to beat them and any team that plays like them. The Boston Bruins, behind 28 saves from goaltender Tuukka Rask and a smothering defensive performance, won 2-0 on Monday to take a two-games-to-one lead in this series.

Game 4 will be Wednesday night here at TD Garden, and it will present the latest and most important pivot point in a Finals that has seen several already. From the third period of Game 1 through the first period of Game 2, the Blackhawks' speed and skill overwhelmed Boston's forechecking and bumper-car style of play. But since then, the Bruins have regained their equilibrium, clogging the middle of the ice, chasing down puck-carriers, and holding Chicago without a goal for the past 122 minutes and 18 seconds of game action.

That the Bruins have neutered the Blackhawks' offense ought not to be surprising. They held the Pittsburgh Penguins, the highest-scoring team in the NHL, to two goals as they swept the Eastern Conference Finals. They're a team that goes bump in the night, and their brand of hockey is working now—putting the onus on Chicago to prove it is capable of adjusting its approach, of abandoning its free-flying philosophy and match Boston's edgy play.

"It's a tight game," Blackhawks coach Joel Quenneville said. "Scoring's going to be challenging, but we've got to be ready to play that kind of game. It's not like we're thinking we just want to go out racing and exchange high-quality scoring chances, because that feeds into what they want to do. We have to be ready to play a patient game and make sure we capitalize when we do get opportunities."

To that end, the Blackhawks will have to overcome perhaps their greatest and most puzzling handicap of these playoffs: their power play. They have seven goals in 62 man-advantage situations, a paltry 11.3% success rate, and went scoreless in five such opportunities Monday. For their part, the Bruins have killed off 26 consecutive shorthanded situations. The New York Rangers' Dan Girardi was the last player to score a power-play goal against them—more than two weeks ago.

"We try to stay compact in our zone," Bruins defenseman Dennis Seidenberg said. "Once the puck is bobbled, if you see a chance to pressure them, we do that. For the most part, we've been doing a good job keeping them to the outside."

It was a mission made easier because the Blackhawks in Game 3 were without forward Marian Hossa, who is tied for the team lead in postseason points with 15 and who did not play because of what Quenneville described as an "upper-body injury"—adding that he's hopeful Hossa will be healthy enough for Game 4. For Game 3, the injury forced Chicago to insert neophyte Ben Smith, who has one goal in 20 career NHL games and had not suited up in these playoffs, into the lineup. As it turned out, Smith was on the ice 2 minutes 13 seconds into the second period, standing just feet from Boston forward Daniel Paille, as Paille lifted the stick of the Blackhawks' Dave Bolland to steal the puck and whip a wrist shot past goaltender Corey Crawford for the game's first goal.

Twelve minutes later, during a Boston power play, the Bruins' Patrice Bergeron completed an around-the-horn passing play—Zdeno Chara to Jaromir Jagr to Bergeron—by stashing the puck behind Crawford. The two-goal lead looked and felt insurmountable, and it was, so rarely did Chicago mount any sort of scoring threat against Rask. "Time's running out," defenseman Duncan Keith said. "We've got to get a goal." More than one will likely be required to win Game 4, but that may be too wild a thought for the Blackhawks to entertain at the moment.