Just more than three minutes into the second period of Thursday night’s playoff opener against the New York Rangers, the Washington Capitals took to the power play for the third time. “It’s playoff hockey,” forward Marcus Johansson said later. “There aren’t going to be too many chances.” Yet here they came, one before the game was a minute old, another late in the first, another to open the second. And there, on that third chance, the Capitals struggled to even keep the puck in the offensive zone. With the Rangers already leading 1-0, the Verizon Center crowd collectively cringed when dangerous New York center Derek Stepan broke away for an oh-no-but-we’re-on-the-power-play chance. “We needed to move forward with our PP,” Capitals forward Troy Brouwer said. “I think they had more chances on our PP than we did.” The playoffs are only a game old, and it’s far too early to establish trends and themes. But consider the two divergent forces that were well-established long before Washington took a 3-1 victory to begin the series: The Capitals have the league’s best power play. And power plays are more difficult to come by as each postseason game goes by, as spring pushes further from winter. “I’m not really too concerned about it,” Capitals Coach Adam Oates said. He doesn’t need to be, because his team won its opener, because its last two power plays of the night looked crisp and because he knows a single game in what could be a long postseason haul doesn’t provide absolutes. But consider how the Capitals got here, to being Southeast Division champions, to being favorites over the Rangers. In the 48 games of this lockout-shortened regular season, they scored 41 goals with a five-on-four advantage. Next highest: Philadelphia and Montreal, each with 35 — a huge gap. That represented 28.1 percent of the Capitals’ offensive output in the regular season, the highest percentage in the NHL. So by almost any measure — efficiency rate, gross number of goals — the Capitals’ power play was lethal. But they also rely on it more than most teams. “It’s huge,” Johansson said. The Rangers, though, enter this series as the least-penalized team in the league. So mix all that together: one team that wants and needs to score on the power play — and is superb at doing so — against a team that rarely takes penalties, competing in an environment in which penalties are less likely to be called. It made that discombobulated power play early in the second period seem weighty.