When hockey has been played at its highest level the last couple years, Pittsburgh Penguins captain Sidney Crosby has consistently emerged as the winner.

The World Championships. The Stanley Cup. The World Cup. It's been unreal.

As good as Crosby was as The Kid, he's been even better as an adult.

And now he's trying to do something that Jonathan Toews, Henrik Zetterberg, Drew Doughty, Patrick Kane, Patrice Bergeron, Anze Kopitar and other stars couldn't do: win back-to-back Stanley Cups in the salary-cap era.

It's all but impossible.

"Part of the difficulty of winning back-to-back is it's very taxing, it's very draining," said Toronto Maple Leafs team president Brendan Shanahan, who was part of the 1997-98 Detroit Red Wings, the last team to do it. "[It's because of] the very short offseason, and you have a big target on your back as well. It's harder to do because of the cap situation, but also it's just hard to do in general. That's why it didn't happen a lot in history, except for some of the dynasty teams."

Crosby had this opportunity once before. In 2010, the Penguins were the reigning champs. They were a great, young team with the only expectation that they become the NHL's next great dynasty. No big deal.

The previous spring, they had denied the powerhouse Red Wings a shot at a Stanley Cup repeat, with Marc-Andre Fleury's sliding save on Nicklas Lidstrom in the final moments burned into the minds of Penguins fans forever.

The next year, Crosby was 22 and had already posted four 100-point seasons. If anybody was going to win back-to-back Cups, it was him. What he didn't have then was the perspective of time. He didn't have the maturity that comes with life experience. He didn't have what he has now.

"There are challenges and adversity and knowing [what] you have to go through that is important," Crosby, 29, said on Monday.

That season, the challenge came in the form of Jaroslav Halak and the Montreal Canadiens. Halak was brilliant as the Canadiens upset the Penguins in seven games to end any hopes of a repeat.

The adversity that followed for Crosby was even more challenging. Multiple concussions cut seasons short for the best player in the game. There was another lockout. Coaching systems were implemented that didn't highlight the strengths of Crosby's game. Rival players knew the buttons to press to get him off his game.

It all took its toll.

"You honestly think at times it's going to kill you. You think you're done. You think you're not the player you were. You're asking yourself those questions," said Colorado Avalanche forward Matt Duchene, who has gotten to know Crosby -- and adversity -- through the years. "Then when it comes back around, it's like, 'Geez, that was one of the hardest things I've been through, and it didn't come close to killing me. It empowered me even more.'"

To say Crosby has emerged empowered after hardships since his first Stanley Cup is an absolute understatement. He is currently on a run as good as any stretch by any athlete in all of sports.

It started with the World Championships in 2015. Crosby surprised Team Canada coaches by joining the team after the Penguins were eliminated from the playoffs. Canada overpowered everyone to win a gold medal in Prague. In 2016, he won his second Stanley Cup ring and won the Conn Smythe as the most valuable player of the playoffs. When the World Cup of Hockey returned to the international stage in September, it was Crosby who led Canada to the championship as tournament MVP.

He kept up the momentum this season by winning the Rocket Richard trophy, which is given to the player who scores the most goals. He scored 44 goals, and he did so in just 75 games after missing time because of a concussion.

Sidney Crosby and the Penguins have a chance to do what they weren't able to after winning in 2009: repeat as Stanley Cup champions. AP Photo/Paul Sancya

Crosby and the Penguins have seen the difficulties up close. The biggest impact of the salary cap is that it cuts into depth. When a star goes down, it's difficult to replace him.

Pittsburgh is dealing with that as it heads into its first-round series against the Columbus Blue Jackets, with the loss of defenseman Kris Letang, who is out four-to-six months with a neck injury. There is no chance that the Penguins would've won the Stanley Cup last spring without Letang.

"With the injuries, we have had guys have to step up to keep pace, and they deserve a lot of credit for allowing us to stay on track," Crosby said.

The Penguins put up 111 points this season, trailing only the Washington Capitals for the most in the NHL. They earned a tough draw in the first round: a Blue Jackets team that was among the best all season in a series that starts Wednesday in Pittsburgh.

Although Crosby is quick to credit teammates for filling the void created by injuries, they don't do it without him, without Crosby maturing into a player who blows through obstacles. He might not put up points at the pace he did as a kid, but he's a more formidable opponent than ever. Part of that is because nobody works on incremental improvements more effectively than Crosby. Those incremental improvements become significant over time.

Carolina Hurricanes' Bill Peters coached Crosby in the 2015 World Championships. After a long morning of meetings before playing the Czech Republic, Peters asked the Team Canada defensemen to stay late and huddle around him in the hallway for one more meeting. He wanted to show five clips on his laptop very specific to Jake Muzzin, Brent Burns and the rest of the Canadian defensemen.

"I look over my shoulder, and there's Sid standing there," Peters said.

He showed the clips to his defensemen and then pulled Crosby aside afterward.

"I said, 'Sid, real quick, why did you come to the D meeting?'" Peters said. "He goes, 'If you thought it was important they should see it, I thought I should see it too, and it would help me.'"

He does that all the time. Crosby attended Penguins penalty-kill meetings for years before he ever played regularly on the PK. He relentlessly studies the game.

On the morning Canada played Russia for the gold medal at the Worlds, Crosby stayed after practice to work on one particular shot over and over. He had assistant coach Jay Woodcroft feed him passes in the high slot. He one-timed the puck repeatedly in the same spot of the net -- far side.

That night, he scored against the Russians on a similar shot.

"It's not a coincidence," Peters said. "That's Sid. He outworks you. His will is unbelievably strong. That's just what he does."

That ability to compartmentalize areas of his game has rounded Crosby's skill set and allowed him to score goals all over the ice. Even with the concussions, opponents say he goes to the net with an absolute fearlessness other skill players don't possess. He plays in a system under coach Mike Sullivan that allows more creativity at a faster pace, ideal for his game. He has also developed his backhand into one as dangerous as a forehand.

"He works both sides of his stick, probably the best of anyone in the game," New Jersey Devils forward Taylor Hall said.

For Crosby, it was simple. As the game evolved, he had to find other ways to be successful.

"There doesn't seem to be as many odd-man rushes," Crosby said. "It's important to be able to create different ways."

And gone are the days when an opponent could get into his head. He's so consistent every single night because he has matured into a player who doesn't get distracted by late hits, trash talk or other tactics teams used to throw him off his game. Blue Jackets forward Brandon Dubinsky is going to try his best to get under Crosby's skin in this series, but he has his work cut out. This is a different Crosby than Dubinsky stalked effectively while with the New York Rangers.

"You can't push him out emotionally anymore. He doesn't allow himself to get frustrated," one veteran coach said. "You used to be able to get him to want to get you back, which became a little bit of a distraction. Now he just plows right on through. He just laughs at you."

The result is that Crosby is completely in sync. It's a rare spot for an athlete. Sometimes athletes reach a high level of individual success. Sometimes they get team success. Every once in a while, things align perfectly, and they get both.

The best hockey player in the world is also competing on one of the best teams in the world.

The result lately for Crosby when that happens has been a championship. If he does it again, raising the Stanley Cup for a second consecutive season, it surely has to be his biggest accomplishment yet.