Not only players must learn how to win.

After a pair of heart-wrenching playoff losses to Mike Sullivan’s Pittsburgh Penguins (44-26-12), head coach Barry Trotz finally solved the puzzle last season on the road to a championship with the Washington Capitals. His hours of tape study are now paying off in his first year with the New York Islanders (48-27-7), as they’ve absolutely suffocated the Pens to grab a 3-0 stranglehold on their conference quarterfinal series.

While it’s too early to count any team out — especially one spearheaded by Sidney Crosby (100 points in 79 games) and Evgeni Malkin (72 points in 68 games) — only four teams have ever overcome such a deficit.

Pittsburgh isn’t really showing any signs of life either. Crosby and Phil Kessel (82 points in 82 games) have offered the odd glimpse of brilliance and the fourth line has been reasonably effective, but the rest of the club has been stymied to the fullest extent by a determined Islanders squad. Trotz seemingly knows every one of the Penguins’ tendencies and vulnerabilities, and he’s concocted the perfect game plan to exploit them. As a result, we’ve seen more temper tantrums than quality hockey from them thus far.

First and foremost, he’s established a defensive fortress.

Unlike many teams that simply run straight at the Pens’ stars in hopes of keeping them in check, the Islanders pick their spots to apply pressure and overwhelm them at the point of attack. Crosby, Malkin, Kessel, Jake Guentzel (76 points in 82 games) and company are constantly looking for threats that aren’t there because New York floods the most dangerous areas in its end. There’s only room up at the blue line since the Islanders feel confident in their ability to block shots (2nd in the playoffs) or use their active sticks to negate second-chance opportunities. Pittsburgh has tried to force its way into the high-percentage spots, but it can’t find the space to fire quality shots on Lehner.

Since the start of the playoffs, only the Colorado Avalanche are producing less offense — which is to say none at all — from that area.

This is not some happy accident. It’s part and parcel of the Islanders’ philosophy and an extension of the Islanders’ stinginess in tight from the regular season, when they ranked fourth in that department. They concede a high rate of scoring chances (23rd in the regular season, 15th in the playoffs), but they stand their ground in the trenches exceptionally well.

That focus on the protecting their house resulted in a stunning defensive turnaround from season to season: The Islanders went from dead last (3.57) to first (2.33) in goals allowed in their first year under Trotz. For this specific series, that approach has made life surprisingly easy between the pipes. Sure, there have been a few leaks here and there — that’s inevitable against world-class players — but Robin Lehner has put up sparkling numbers (1.62 GAA, 95.1 SV%) without ever needing to steal the show.

Though many equate defense with effort, there’s a difference between working hard and working smart. Trotz’s troops are dialed into the latter: They hustle only when there’s a chance to disrupt a play or cause a turnover. Otherwise, they merely keep the Pens in front of them and dare them to attack the middle of the ice. As the action moves from the perimeter to the slot, New York shifts from conservative to aggressive, dogging the puck until it either regains possession or redirects play toward a safer area.

Stars thrive on defenders over-committing, as Crosby and Malkin have delivered Hall of Fame careers out of picking teams apart when they attempt to bear down on them. The Islanders are content to maintain an airtight posture and just wait on the Pens.

Either sling low-percentage bids at us from the outside or lose the key puck battles inside. Your move.

In more active schemes, blueliners Nick Leddy, Johnny Boychuk, Scott Mayfield, Devon Toews, Adam Pelech and Ryan Pulock might struggle to keep pace with the opposition. We saw that as recently as last season with Doug Weight’s horrendous defense. Trotz has devised a plan to maximize the effectiveness of his personnel, focusing on positioning and stick work above all else. You can rag the puck all you want on the fringes. Once you enter the high slot, the Islanders absolutely swarm you.

No one enjoys being shut down. Being shut down while posting the second-most shot attempts, scoring chances and high-danger opportunities in the playoffs? That’s all the more frustrating.

Trotz’s preparation is allowing his team to capitalize on that frustration too, as the players seem to understand precisely when to exert pressure and launch a counterattack. Better still, they play within themselves. Other than Mathew Barzal (62 points in 82 games), who is capable of producing pure magic, New York keeps risks to a minimum and takes whatever is granted by its opponents.

In the case of this matchup, it’s a whole lot of rush chances. Sullivan’s system has been defined by pure speed, but there doesn’t appear to be much structure. When the star players get the puck, they’re given the license to improvise. This fosters a creative and potent offense, but there are glaring lapses in their three-zone play. New York has jumped all over those. Every time a Pens forward is a bit careless or a defenseman pinches without adequate support, the Islanders smell blood in the water.

Throughout the series, they’ve transitioned from defense to offense so quickly that the Pens don’t know what hit them. That rapid-fire offense has vaulted the team from 22nd to fifth in goals per game since the postseason began. Meanwhile, Pittsburgh has dropped from sixth to 15th…out of 16 teams.

Trotz’s strategy may not work against teams that are stronger in the trenches, but through three games in the first round, he’s won the coaching battle in emphatic fashion. The fact that no single player stands out as the difference-maker is a testament to that. The Islanders have bought in and displayed their commitment on every shift in every zone. It’s almost as if they know their game plan is superior.

Sullivan has no answers — perhaps because his horses have provided most of them in his tenure. A few roster changes haven’t helped either. At any rate, he no longer holds the upper hand. Trotz has figured him out and smothered the Pens’ championship mettle.

It’s up to Pittsburgh’s bench boss to learn, adapt and get his team back on track.

And the clock is ticking.