Joel Quenneville remembers years past when NHL teams leading going into the third period could feel comfortable chalking up two points. A win was a pretty sure bet.

Earlier this season, his Florida Panthers erased a four-goal deficit to win a game. And then they did it again. Even the three-time Stanley Cup-winning coach didn’t see that coming.

“We didn't envision coming back either game,” Quenneville said.

It’s becoming easier than ever to envision. There have already been five four-goal comeback wins this season, tied for the most in NHL history. And the 18 three-goal comebacks are the most through the same number of games in 30 years.

No lead is safe.

“Used to be the dreaded, two-goal lead is the most dangerous in hockey, but now it seems like the four-goal lead's the hardest one to hold on to,” Tampa Bay Lightning coach Jon Cooper said. “Teams believe they can come back at any time.”

Coaches and players point to a number of different factors for all the rallying going on, ranging from rules designed to create more offense to better power plays, more skill and talent, and human nature when it comes to holding a comfortable lead or facing a difficult deficit.

“It's very difficult to hold leads now just with some of the rules that have been added,” said coach Todd Reirden, whose Washington Capitals recently erased a three-goal deficit to beat the New York Islanders. “Just different little nuances that have helped scoring increase in the league. It's just the way that penalties are called, too, and the league wants offense and they love that aspect of teams coming from behind like that.”

Those rules include more penalties called for obstructing, hooking, holding and slashing and increased advantages on faceoffs for the offensive team. Just like the standings that are set up to be neck-and-neck down the stretch to the playoffs, the modern game is designed for no team to be out of a game.

When David Quinn’s New York Rangers went down 4-0 at Montreal this season, the second-year coach considered it a little unfair based on their effort. They won 6-5 in regulation.

“One of the things we talked about in between the first and second period was: 'Don't play the score. If you do the right thing over and over again, the game will reward you,'” Quinn recalled. “And I thought that's what happened. Within a game, you've got to be mentally tough, and you're going to have to have resiliency.”

See the Panthers, who stunned Anaheim and Boston with those four-goal comebacks. Quenneville has been behind an NHL bench for a long time and doesn’t have a scientific explanation for this phenomenon.

“You get a fortunate break on a bounce here, and it can really shift the momentum,” Quenneville said. “There's been a lot of offense in this year's game, teams going for it. You've got a 4-0 lead, whether you take your foot off the pedal and all of a sudden you maybe relax a little bit, but the other team's pressing, they're pinching, they're taking more offensive zone chances and thinking that way. You get a couple of breaks and all of a sudden, the other team's on their heels.”

Much of it is psychological. Players after building a big lead could naturally think their heavy lifting is over for the game. Those on the other side are just getting started.

“The team that's ahead, as much as you fight it, there's a natural instinct to just ease off the gas a little and give (up) opportunities,” said Matt Niskanen, whose Philadelphia Flyers recently beat the Bruins in a shootout after trailing by three goals. “Mentally, you tell yourself, 'Don't let up, keep playing the same way because we're having success for a reason.' It's a really hard thing to fight.”

After reaching Game 7 of the Stanley Cup Final, the Bruins lead the Atlantic Division at the All-Star break despite a penchant for blowing leads.

“We've got to bear down,” Boston center Patrice Bergeron said. “You can't just have a good effort, be satisfied with that, and then just play for a half a game.”

Half a game isn’t enough, especially since hockey has moved toward more offensively skilled players and away from those tasked with keeping the puck out of the net. There’s also the fact that 25 of 31 teams are either in or within 10 points of a playoff spot, and it’s hard for teams to dominate a whole game — let alone a season.

“It just shows the parity of the league and that on any given night, everybody can beat somebody else” Reirden said “It's extremely competitive.”

BKN--PELICANS-WILLIAMSON’S SURGE

NEW ORLEANS -- Zion Williamson’s sublime 17-point surge in a span of barely more than three minutes in his NBA debut could become part of New Orleans sports lore. A narrow loss to the Spurs is overtaken by the prospect of a young superstar in the making. By Brett Martel.

New Orleans — Zion Williamson’s sublime 17-point surge in a span of barely more than three minutes could very well become part of New Orleans' pro sports lore — even if the final score won't.

For the Pelicans, a narrow loss to a well-coached, savvy San Antonio Spurs team carried far less weight than the burgeoning form of a young superstar in the making.

“The way he came out was very poised,” veteran Pelicans guard Jrue Holiday said of Williamson. "The way he played ... bringing energy, especially down the stretch, was something that I guess you don’t really see from somebody so young. But even on top of that, we are almost in February and he hadn’t played a game yet, so for him to be able to come out here and do that his first game is pretty elite.”

Extraordinary hype, fueled by social media, has followed the affable, 6-foot-6, 285-pound Williamson since his high school days in Spartanburg, South Carolina. It only increased during his one stellar season at Duke, making him the consensus No. 1 overall NBA draft pick well before the Pelicans won the draft lottery and the right to select him.

Pro basketball fans had to wait an extra three months to see how Williamson's rare combination of size and skill would translate in a meaningful NBA game because of the cautious and comprehensive approach the Pelicans took to their prized rookie's rehabilitation from arthroscopic surgery on his right knee.

But it took only one game for Williamson to do something extraordinary.

He made all four 3s he attempted in the fourth quarter Wednesday, stirring the Smoothie King Center crowd into a jubilant frenzy. In between, he laid in an alley-oop lob and put back an offensive rebound with a reverse layup.

“It was nice to experience those emotions,” Williamson said. “I was happy to be out there and be able to run out there again, but what was going through my mind was just, ‘Be calm.’”

Williamson's final statistical line was 22 points on 8-of-11 shooting to go with seven rebounds and three assists in 18:08 on the court.

“The way he plays, that's something he can do every day,” Holiday said. “Adding Zion is a big part to what we want to do here and our success."

Fans wanted to see more, but coach Alvin Gentry said he couldn't heed their chants of “We want Zion!,” during the final five minutes of a 121-117 loss.

“The medical people said that was it,” Gentry said, alluding to precautionary restrictions placed on Williamson's playing time in the early days of his return to action.

“Me, personally, I don't want any restrictions," Williamson said. "But I'm not a doctor or a trainer, so I've just got to listen to them.”

The Pelicans are back in action twice in four days, hosting Denver on Friday and Boston on Sunday. If Williamson's 19-year-old body responds well to his early action, his playing time is expected to lengthen.

“What you saw there is a taste of once we really get settled in and he gets settled in, you can see that there’s a lot of things we can do with him,” Gentry said. “There’s a lot of potential there. It was good to see him do that, but you know I think there’s a really, really high ceiling that he can reach.”

Everything about Williamson's debut exuded a big-event vibe. The game was sold out and hundreds of fans were waiting to pour into the arena when the gates opened about an hour before tip-off.

“The energy was there from warm-ups," Pelicans guard Lonzo Ball said. “That is the most people I have seen coming out before the game even started.”

Tip-off was pushed back 90 minutes to accommodate national TV and Pelicans media relations staff said they'd issued about 165 credentials, more than five times the typical number for a mid-week game in January.

For a little more than three quarters, when Williamson had five points and four turnovers, it looked like his first game would disappoint the lively, capacity crowd that came to see him. Then, suddenly, Williamson had the place on its feet and in a state of near delirium.

Holiday noted that Williamson had been rocking arenas since high school, adding rhetorically, “As exciting as it was, is it really that much of a surprise?”

Perhaps not. But it was memorable.