The seventh game belonged to the Bruins a year ago, from the first round to the last, en route to their first Stanley Cup in 39 years. The Bruins played three Game 7s last spring. They won them all. They never so much as trailed in any of them.

And so tonight at the TD Garden, the Bruins return to that place where entire seasons teeter and where they have most recently done their very best work.

The edge.

We all know how Game 7s work, of course, and we all know what they mean. There is simply no more ground to give now. Game 7 requires the utmost focus, maximum intensity, commitment to precision and detail. Nowhere is that truer than in the NHL, where the speed and continuity of play mean that the smallest mistake at any given time can be the difference between winning and losing.

Quite simply, no other sport can replicate it. Baseball and football have built-in stoppage between plays. Basketball is inevitably disrupted by a succession of whistles, and the speed of the game does not compare. But in hockey, the smallest things are indisputably connected, one leading to the other.

In Game 7 of last year's first-round playoff series between the Bruins and Montreal Canadiens, the Bruins won in overtime, on a deflection, to defeat the Canadiens in the game and series, 4-3. Do you remember the sequence that preceded the goal? There was a faceoff to the right of Montreal goalie Carey Price. Bruins center David Krejci won the draw, but the puck ended up in the corner to Price's right. The Bruins and Canadiens battled for the puck, moving from one corner to the other, before the puck popped into the air.

Bruins forward Milan Lucic grabbed the puck, dropped it to his stick and shuttled a pass to Nathan Horton, who blasted a slap shot through a crowd that deflected off a Canadiens defenseman and squirted past Price.

What if Krejci had lost the draw? What if Lucic had mishandled the puck? What if Horton's shot had made it through cleanly, without interference?

So it goes in the NHL playoffs, the sports world's purest incarnation of the butterfly effect.

On a grander scale, the effects of Game 7 also translated. Despite having leads of 2-0 and 3-2 in their Game 7 against the Canadiens, the Bruins wobbled. They blew both leads. They nearly choked. Under coach Claude Julien, the Bruins had been to a seventh game on three prior occasions and lost them all, two of them coming on their home ice. Against the Philadelphia Flyers only a year earlier, the Bruins raced to a 3-0 first-period lead against the Flyers before ultimately tumbling to a 4-3 defeat, blowing a 3-0 series lead in the process.

Had the Bruins lost last spring to the Canadiens, think of what we would have been saying about them for the better part of the last year. They can't close. They choke under pressure. Instead, the Bruins used their Game 7 win as a springboard, particularly against the Tampa Bay Lightning in Game 7 of the eastern Conference finals.

That series, too, went to a seventh game. This time, buoyed by their success in Game 7 against Montreal, the Bruins turned in the kind of performance that left almost nothing to chance. They outshot the Lightning 38-24. They controlled the puck and generally dominated play. They were fortified by their Game 7 win over the Canadiens and subsequent sweep of the Flyers (in the second round), the butterfly effect this time working on a far greater level.

By the time the Bruins got to game 7 against the Vancouver Canucks in the Stanley Cup finals, Game 7 belonged to them. They owned it. The victory over Montreal, albeit a little shaky, came on the Garden ice. The victory over Tampa Bay was far more convincing, but again came on the familiar surface at the TD Garden. Game 7 of the Cup finals was played in Vancouver, where the Bruins had lost Games 1, 2 and 5 of the series, where Horton (now injured) poured water he had transported from the team's home in Boston.

It's our ice now.

In Game 7 against Vancouver, the Bruins scored once in the first, twice in the second, once more in the third (an empty-net goal). The Canucks never scored at all. The Bruins became the first team in NHL history to win three Game 7s in the same postseason, the scores of their respective victories over the Canadiens, Lightning and Canucks looking like their very own growth chart: 4-3, 1-0 and 4-0.

Along the way, here is what the Bruins learned: that a team can win Game 7 with a little luck, or that a team can win Game 7 by leaving nothing to chance. They learned that a team can win Game 7 at home or on the road. They learned that Game 7 can bring them to the greatest heights as surely as it had delivered them to the cruelest depths, and that the distance between can be as fine as the edge on their skates.

Game 7 returns to Boston tonight. Most recently, it has belonged to the Bruins. It is seemingly theirs to win. Or to lose.