10 - Number of times the Caps went at least two games without a power-play goal last season, including five stretches of three or more games. In fact, going back to the start of the Barry Trotz era, the Caps have been held without a power-play goal at least two games in a row 27 different times, including the two to start the 2016-17 season - and yet have the best power-play percentage over that stretch, capitalizing on 23.2% of their chances (115 for 496).
This season, as young as it is, has seen the Caps go goalless with the extra man through two games (eight opportunities total), but it's not as simple as all that. For one thing, they faced the Penguins and Islanders - aka two of the top-five penalty-killing teams in the League last season. For another, those top-five penalty-killing units were pretty effective against the Caps' top-five power-play unit last year, as Washington managed to go just three for 26 against the two teams in the regular season (eight for 49 overall).
That said, dating back to 1987-88* the Caps have never started a season without at least one power-play goal in their first two games... so clearly it's time to panic.
*1987-88 is the earliest season for which specific game data is available via Hockey-Reference.com