The Boston Celtics’ season started with a record-tying 3-point night. It was a sign of things to come. The Celtics broke the NBA record for 3-pointers in a season Friday night in a victory over the Phoenix Suns. “We’ve got a really good team,” star Jayson Tatum said. “A talented group of guys. When we play to our strengths, everyone, for the most part, we space the floor and (everyone) is a threat from behind the line. It’s a credit to guys for working on their game. It’s what makes us special.” On opening night, Boston made 29 3-pointers in a blowout victory over the New York Knicks when the Celtics raised their championship banner. They set the mark, surpassing Golden State´s total from two seasons ago, when Payton Pritchard hit a left-wing shot 3:40 into the second quarter for No. 1,364. Kristaps Porzingis tied the mark when he up-faked a defender, dribbled to his left a few feet before hitting one from the top with 9:37 left in the second quarter. Boston finished 14 of 39 from 3-point range in the 123-103 victory to push its season total to 1,370. Boston also is third in league history, connecting on 1,351 en route to the NBA title last season. “Less than half of those attempts were from 3 because of the way they were defending us,” Boston coach Joe Mazzulla said, when asked what the record meant. “We were able to fight for good looks versus the coverage. That’s the most important thing; continuing to figure out how we’re being defended. … It’s a credit to the guys for continuing to make the right reads.” At times during the previous two seasons, Mazzulla was questioned about why Boston took so many 3s when it was struggling. He continued to defend the team’s shot choices. On Friday, the Celtics hit 3s with some flare early in the game when Jaylen Brown banked in a 35-footer as the shot clock expired and Tatum dribbled in from midcourt, knocking down a straight-a-way 29-footer a few minutes later.