The Vegas Golden Knights are going to the playoffs. (John Locher/AP)

The original plan in Las Vegas could have been best described as aggressively playing the long game. Golden Knights owner Bill Foley repeated the mantra that his team would shoot for the playoffs in three years, and the Stanley Cup in six. That was the reasonable course even for an impatient owner who wanted to win right away.

“I’d love to have offensive powerhouse, juggernaut like the Penguins, but it took them a long time to get there,” he said in June 2016, ahead of the NHL’s expansion draft. “We’re going to have to work our way into that.”

The process has certainly sped up.

After beating the Colorado Avalanche, 4-1, Monday night, the Knights have already clinched a playoff berth. They lead the Pacific Division with 103 points through 76 games, and are fourth in the entire NHL.

They’re the first expansion franchise to make the Stanley Cup playoffs in an inaugural season since the Edmonton Oilers and Hartford Whalers each did it in 1980.

But beyond the bounds of hockey, the Golden Knights are only the second team since 1990 in a major North American sports league to earn a spot in the postseason in its first season. The other team was the NBA’s New Orleans Hornets in the 2002-03 season, but the Hornets were an existing team that relocated from Charlotte. Every other debuting team — all 18 of them — finished no better than next-to-last in their first season.

And taking all those expansion teams into consideration, the Golden Knights’ resume so far is clearly the best. The Oilers and Whalers each finished their first seasons below .500, with 69 and 73 points, respectively. The 2003 Hornets finished with a 47-35 record, and the Golden Knights have already assured themselves a better regular season record.

And all three teams were knocked out of the first round of the playoffs. The Oilers and Whalers were swept in three games, while the Hornets lost a six-game series against the Philadelphia 76ers.

The Golden Knights, meanwhile, are in line to host a first-round playoff series.

So why, exactly, is Vegas so good?

It’s all about which players were available to General Manager George McPhee. In the 2017 expansion draft, every NHL team had to protect either 10 skaters (seven forwards and three defensemen) and a goaltender or any eight skaters and goaltender.

McPhee could then draft any player who wasn’t protected and in 2017, there were some pretty good players available, as Washington Post hockey beat writer Isabelle Khurshudyan explained. The Knights scooped up winger James Neal, who scored 23 goals last season with Nashville, and a No. 1 goaltender in Marc-Andre Fleury, a three-time Stanley Cup champion with Pittsburgh.

During previous NHL expansions, teams could protect far more players: 14 skaters (nine forwards and five defensemen) and a goalie in 2000 when Columbus and Minnesota entered the league, or any 15 skaters and two goalies in 1974 when Washington and Kansas City (now New Jersey) got started. That left some pretty slim pickings for new clubs to choose from.

“The protected list was a joke,” Jack Lynch, a defenseman on that 1974 Capitals team, told Khurshudyan. “If you look back at the players who were exposed for the expansion draft back then, you were getting basically access to the 17th, 18th and 19th player on the existing NHL teams’ rosters.”

The results were ugly. Washington and Kansas City combined to win 23 of 160 games that season. There was no winning right away with that kind of foundation.

The Knights, on the other hand, might not need six years to win a Stanley Cup.

Read more from The Post:

Gregg Popovich, Spurs hit the Supreme Court, surprising some Illinois high schoolers

Volvo Ocean Race yachtsman John Fisher falls overboard, is presumed lost at sea

Johnny Manziel, hoping to return to the NFL, works out for all 32 teams at Texas A&M pro day

Josh McDaniels says ‘clarity’ from Robert Kraft and Bill Belichick led him to jilt the Colts

Rams sign Ndamukong Suh and are in the market for Odell Beckham Jr., too?

London mayor wants a Super Bowl, which may be overly optimistic