The Post Sports Live crew talks about the Capitals style of play, the pressure on GM George McPhee and the critical upcoming stretch between now and the break for the Olympics, which begins on Feb. 9. (Post Sports Live/The Washington Post)

The Washington Capitals are 47 games into this NHL season, but as shown in their latest loss Wednesday night to the Eastern Conference-leading Pittsburgh Penguins , they have yet to identify any type of winning formula.

Uncertainties about the roster’s configuration and strength have lingered for months, and they remain as prominent and problematic as ever as the Capitals continue to show a persistent ability to self-destruct.

Following the 4-3 loss to Pittsburgh, the middling Capitals are 4-5-5 in their past 14 games and fighting to stay afloat as the schedule grows increasingly packed with important games.

The shootout success that helped earn victories and points early in the season — Washington went 8 for 11 in shootouts to start the year — has dried up, leaving little to mask the fact that the Capitals have a .414 winning percentage in games decided in regulation, eighth worst in the league. And that puts a spotlight on the imperfections that prevent Washington from finding ways to succeed.

Defensive depth

There may have been no better indicator of the Capitals’ questionable blue-line depth than when John Erskine played top-four minutes to start the season despite clearly being limited by an offseason knee injury. Erskine has acknowledged that he likely shouldn’t have played, but with little NHL experience among its defensemen, the coaching staff turned to the 33-year-old.

Fast-forward to January. The Capitals have used 12 defensemen this season, including four rookies, tied with Edmonton and Winnipeg for the most to play at least one game. While injuries caused much of the disruption, the current group has been stable for a month. Neither of the bottom two pairings, however, are significantly more consistent.

John Carlson and Karl Alzner are the clear-cut top shutdown pair; they face the toughest matchups and see the most ice time as a unit. Mike Green and Dmitry Orlov, both offensively gifted players, present a high-risk, high-reward scenario. They can excel but are also vulnerable to odd-man rushes and turnovers in their own zone, such as Tuesday, when Orlov’s inability to handle a pass led to a San Jose goal.

Then there’s the third unit, which for the past five games has paired Erskine with rookie Connor Carrick, a combination whose lack of mobility and experience, respectively, can be exposed against talented opponents.

Erskine is tied for the second-lowest Corsi percentage (46.6) in five-on-five play among defensemen to play at least 20 games with Washington this season. (Corsi percentage is essentially a plus-minus statistic that measures shot attempts.) That means that when he’s on the ice, more than 53 percent of the attempted shots are against the Capitals. Carrick, meanwhile, has appeared in only eight NHL games and is a junior-eligible rookie.

Thus, it wasn’t a coincidence against the Penguins — when Erskine and Carrick were routinely out against Evgeni Malkin’s line — that the pair was on the ice for a combined 27 attempted shots against and 12 for, along with a goal against.

Precarious leads

The loss in Pittsburgh marked the fifth time this season the Capitals have been defeated after losing a third-period lead, but they routinely struggle to build on their own momentum. The team has given up a lead in nearly half of its games (23). They’re 10-9-4 in those games.

“That one’s a really frustrating one for us,” Eric Fehr of frittering away three one-goal leads to the Penguins. “You’re on the road, you have a one-goal lead, you want to sit on it. That’s just the way it’s been for us lately; we haven’t been able to hold on to them and let them back in it.”

Washington also gave up its league-leading 21st quick-response goal against the Penguins, as Taylor Pyatt became the latest player to score within two minutes of a Capitals goal.

Forward aren’t jelling

In the past seven games, Coach Adam Oates has used three configurations for his top two lines and two on the third and fourth lines. There is no real sense of stability with any of the units as the team searches for elusive chemistry.

The back-to-back games this week featured opponents (San Jose and Pittsburgh) that Oates described as being on autopilot: teams that have been together under the same system for enough time to develop cohesion and a rhythm. The Capitals don’t yet have that luxury.

It’s difficult to measure the impact a steady rotation has on output for each player, but consider that only Alex Ovechkin has double digits in even-strength goals with 22. The next closest are Joel Ward (nine) and Mikhail Grabovski (eight). They still rely on the power play, which has had largely consistent units throughout the season, for 30 percent of their offensive output, which is by far the highest amount in the league.