Once again, Tyler Seguin proves Bruins made a huge mistake

Tyler Seguin had three goals in a 5-3 Dallas victory Tuesday at TD Garden.AP/Associated Press

Only two-plus seasons in, trading Tyler Seguin looks like a horrible mistake. The Dallas superstar, who is still only 23, could have 10-plus more years to compound the pain of a regrettable deal.

There is no questioning Seguin's talent. Not after a three-goal, six-shot eruption at TD Garden on Tuesday that led the Stars to a 5-3 win. The ex-Bruin is one of the most skilled players in the league — a flammable package of speed, hands, creativity, and predatory offensive instincts.

That he's doing this for another team didn't have to happen.

"It's just in the past now," Seguin said of the prospect of being a lifelong Bruin. "I've moved on. I'm loving living in Dallas. I'm loving being a Dallas Star."

Seguin didn't want to leave. He planted roots in friendships with former linemates Brad Marchand and Patrice Bergeron that will last forever.

He liked it in Boston. Probably too much.

The Bruins weren't sure about his courage. They weren't sold on his defensive reliability. But they were certain enough about the danger of Seguin's off-ice behavior to send away a generational talent in a package that returned Loui Eriksson, Joe Morrow, Reilly Smith, and Matt Fraser.

Smith and Fraser are gone. Morrow could become a second-pairing defenseman. Eriksson is a very good player. But the versatile wing does not have Seguin's ability to turn a game upside down and defensemen inside out.

Eriksson is 30 years old. He is playing for his final score, which could happen outside of Boston. Seguin, under contract through 2019, could be in Dallas for two more extensions.

"[Seguin's] becoming a great centerman for this team," said linemate Jamie Benn. "He's the No. 1 center. We put a lot of pressure on him to be the best. I'm sure he puts a lot of pressure on himself. We need to lean on him. We need him to play a responsible game at both ends of the rink. He's definitely doing that."

Seguin was a good player before the trade. He's become special after it.

Being told you're not wanted does not feel nice. The trade helped to push Seguin to develop into a difference-making star. On Tuesday, Seguin got to show the Bruins they acted too quickly. It was his seventh career hat trick. But before the win, Seguin had not scored a goal in four games against his former club.

"It feels good," Seguin said of scoring a hat trick and beating his old team. "It feels good to win here. It's a tough building to win in. It always feels good to score. I'm very happy with how I responded after playing a bad game in Toronto."

Seguin launched his scoring barrage at 5:46 of the first. With Zdeno Chara and Patrice Bergeron caught up the ice, Seguin took a feed from Jason Spezza and advanced against Kevan Miller. It was not a fair matchup. Miller backed up. Seguin threaded an off-wing snap shot between Miller's legs and past Tuukka Rask to give the Stars a 1-0 lead.

Two more mistakes gave Seguin two more sniffs. He buried both.

At 4:31 of the second, Brett Connolly hooked Valeri Nichushkin in open ice. Six seconds later, Seguin tucked home the first of two power-play goals. Benn won a faceoff against Joonas Kemppainen, then broke for the front of the net. John Klingberg gave the puck to Seguin on the left-side half-wall. With Benn screening Rask, Seguin stepped off the boards and launched a slapper into the net.

Then when Torey Krug bunted a puck over the glass at 1:06 of the third, Seguin completed the trick. This time, Seguin needed 12 seconds of power-play time to do his thing. Spezza snapped a cross-ice pass onto Seguin's blade. Rask tried to get in front of Seguin's one-timer, but Seguin made his ex-teammate look silly. He does that to a lot of goalies.

Had Seguin been more responsible on and off the ice, he would still be a Bostonian. The Bruins signed him to a six-year, $34.5 million extension before he started his third NHL season. The contract looks like a bargain.

Instead, he's just another tourist. Before Tuesday's game, Seguin took a walk in Boston Common. People didn't just recognize the ex-Bruin. They thanked him.

"I've been here a few times since I got traded away, but it's like I still play here, especially in the streets," Seguin said. "People are always friendly. I think the great thing about this city is that no one's really talking bad, especially when I'm walking around. It's, 'Thank you for the Stanley Cup.' It makes this city special."

Seguin has Benn, the NHL's best left wing, as his perpetual running mate. Coach Lindy Ruff loaded up his top line against the Bruins by putting Spezza on Seguin's right side. The points are just about guaranteed to come for Seguin given his surroundings and his skill.

The scary thing is that Seguin is still improving. His best years are yet to come. They'll be as good as he wants them to be.