SAN JOSE, Calif. — If the Islanders held leads all year the way they have for the past week, they would be battling the Rangers for first place in the Metropolitan Division instead of fighting for their playoff lives.

But given the urgency of the situation, it’s best not to dwell on what could have been for a team that scored its first two empty-net goals of the season within the last seven days and is now on a four-game winning streak, having led and closed out three straight in the final period.

“I think just sticking with our game plan,” Noah Dobson said after the Islanders skated with a 3-2 lead for the final 19:05 of a 4-2 win over St. Louis on Tuesday. “We didn’t try and change the way we were playing. We were just playing a solid game.”

For much of the year, the Islanders did exactly the opposite, retreating into a defensive shell and hoping to win games by one-goal margins.

It proved a losing strategy as they repeatedly blew leads, allowed goals at five-on-six and dropped like a rock in the standings.

When Patrick Roy took over as coach in mid-January, that was one of the first things he wanted to fix.

Now — like the rest of Roy’s vision — it is coming into being.

Despite being in a position to defend on Tuesday, the Islanders looked nonplussed.

They kept looking for chances to attack, kept the Blues to the outside when they didn’t have the puck and Mathew Barzal quickly scored into the empty net when Blues netminder Joel Hofer was pulled.

Now, the Islanders will take a four-game winning streak into Thursday’s game against the Sharks, tied for their longest of the year.

“I was surprised to hear that was the first [empty-net] goal we scored against Detroit [last Thursday],” Roy said. “But hey, if you do a good job and if you play well, swarm correctly, good things will happen and it’s exactly what happened on that one. Great job by Bo [Horvat] in the corner and drive it to Barzy for an empty-netter all by himself, basically.”

“I think we’re just going out there with more confidence,” Dobson said. “There were points earlier in the year when we were fighting it a little bit, but I think when you get the results that gives you confidence. I think the guys, everyone knows their job. Guys are buying in, going out with confidence.”

As a result, the Islanders look like a whole new team.

And their playoff chances have a whole new life.