Boston Celtics guard Marcus Smart insists his side's run to the NBA Finals has been borne of a more balanced defence heading into Game 2 against the Golden State Warriors.

The Celtics gave up the fewest points per game in the regular season at 104.5 while leading the league in defensive rating (106.9) and net rating (+7.5), while they only trail the Milwaukee Bucks for defended field goals made these playoffs at 43.3 per cent.

Smart, who received the Defensive Player of the Year and a third All-Defensive First-Team selection this season, has been a significant contributor in that regard with 1.2 steals along with his 15.7 points per game in these playoffs.

The 28-year-old believes it has been a collective effort for Boston in comparison to previous seasons, however, with every player pulling their weight.

"No offence to those other teams, but there was always somebody on the court that we had to cover for," he said. "Teams did a good job of exploiting that, and especially in the playoffs.

"It's all about adjustments and match-ups, and if it ain't broke don't fix it, so somebody would always pick on a guy that we had and we'd always have to help, and it put a strain on our defence. This year, kind of tough to do that.

"In every position, everybody can hold their own and switch and guard multiple positions, and that's what makes us stronger."

It was the other end that gave the Celtics Game 1 in San Francisco on Thursday, though, converting on 21 three-pointers at an eye-watering 51.2 per cent.

Jayson Tatum's dribble penetration was key, allowing for defensive collapses that then created relatively open looks for his teammates.

Smart believes that might change in Game 2, with the Warriors defensive help staying a little closer to home.

"I wouldn't say we were surprised," he said. "You've got two great players in Jaylen and Jayson on your team, everybody's focused on those guys, going to make everybody else beat you and you live with the results.

"An adjustment I can see them making, just a little bit more tighter on us and trying to make our shots even tougher, not that open. We're basketball players, just like those guys and we're going to have to adjust to whatever they do."