PITTSBURGH -- The Pittsburgh Penguins' quest for a third straight Stanley Cup championship ended Monday.
The Penguins lost 2-1 in overtime to the Washington Capitals in Game 6 of the Eastern Conference Second Round at PPG Paints Arena, their first loss in a Stanley Cup Playoff series since hiring coach Mike Sullivan on Dec. 12, 2015.
After defeating Washington in the second round each of the previous two seasons, Pittsburgh couldn't do it one more time.
[RELATED: Capitals defeat Penguins in Game 6, advance to East Final | Complete Capitals vs. Penguins series coverage]
Here are 5 reasons the Penguins were eliminated in the second round:
1. Lack of depth
Center Sidney Crosby and forward Jake Guentzel carried their dominant performance from the first round against the Philadelphia Flyers into this series, at least until Guentzel was held without a point in Games 5 and 6. The supporting cast never truly showed up.
Center Evgeni Malkin scored the game-winning goal in Game 5, but forwards Phil Kessel and Derick Brassard were held without a goal.
Pittsburgh's third line played a large role in its consecutive championships. That unit, and the fourth line, were nowhere to be found this time.
"They've been a hungry group and they've accomplished so much," Sullivan said. "I couldn't be more proud of them as their coach. … We're going to have to digest it and see what we can learn from it."
2. Murray's inconsistency
At times, 23-year-old goaltender Matt Murray looked like the player who won the Stanley Cup the previous two seasons. At others, he allowed goals that would have been uncharacteristic for him in either of those seasons.
After struggling, relatively speaking, through an injury-plagued regular season, Murray never showed the same consistency he had previously. He allowed four goals on 22 shots in Game 3, one on 20 in Game 4, four on 30 in Game 5, and two on 30 in Game 6.
Those ups and downs were costly.
Video: Penguins drop Game 6 to Capitals, lose series
3. Losing late leads
The Penguins held a one-goal lead entering the third period of Games 3, 4 and 5. They won one of them, 3-1 in Game 4.
After battling back from trailing by two goals in the third period for a 3-2 win in Game 1, Pittsburgh didn't have much success late in games as the series progressed. They never led in Game 6 and failed to break a 1-1 tie in the third or overtime to avoid elimination.
"The important thing is to get better every game," Crosby said. "Coming off the last couple of games, I thought we were playing some good hockey."
4. Key pieces missing
Malkin missed the first two games with a lower-body injury. Pittsburgh managed to win one of those two, but when he returned, he never reached the level of play he usually does.
He did score the game-winner in Game 5, but that was his only goal in four games this series.
"We work hard every game," Malkin said. "I know it's a sad day for us, but we look forward. … Be better next year."
Forward Carl Hagelin missed the first three games with an upper-body injury. His speed and penalty-killing were noticeably absent when Penguins lost two of the first three games.
Video: WSH@PIT, Gm6: Capitals, Penguins exchange handshakes
5. Home ice struggles
After losing two of three home games to the Flyers in the first round, the Penguins had a repeat performance against the Capitals. Pittsburgh lost 4-3 in Game 3 at PPG Paints Arena before winning 3-1 in Game 4 and losing 2-1 in overtime in Game 6.
During the regular season, the Penguins were 30-9-2 at home and 17-20-4 on the road. They were able to overcome their poor home performances in the first round by winning each of their three road games, but weren't as fortunate a second time.
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