There are several reasons why the Boston Bruins were able to eliminate the Washington Capitals from the first round of the 2021 Stanley Cup Playoffs in just five games, but the biggest factor was unquestionably the penalty kill.
Our key matchup before the series started was the Bruins' penalty kill (second-best in the NHL) versus the Capitals power play (third-best in the league).
The B's won this battle decisively, and the Capitals weren't able to overcome it.
"They played unbelievable. That was one of the differences. We really killed that power play," Bruins goalie Tuukka Rask said after his team's series-clinching Game 5 win Sunday night.
"We made it tough for them to enter the zone a lot. We were pressuring a lot, and not giving them too much time and space. They have good players, so they're going to get that time sometimes, and you're going to have guys running out at (Alexander) Ovechkin because he's looking for that one-timer. I think we blocked close to 10 shots that were absolute bullets, so huge credit to our D."
Even though the series lasted only five games, the Capitals had more than enough chances to capitalize on the power play and make the Bruins pay for taking way too many penalties -- several of which were avoidable.
Washington had 21 power-play opportunities -- the most of any team in the playoffs entering Monday. If Bruins fans knew that would be the case through five games, they probably would've expected the B's to be trailing in the series entering a Game 6.
Instead, the Bruins penalty kill gave a fantastic performance. It allowed only four goals in those 21 opportunities, holding the Capitals to a 14.3 power-play percentage in the series compared to Washington's 24.8 percent mark during the regular season. Boston's PK was tremendous in Game 4 with a 6-for-7 success rate before going a perfect 4-for-4 in the Game 5 clincher.
The Bruins' impressive penalty kill performance went beyond just keeping the Capitals off the scoreboard. The B's didn't give the Caps much of anything in those situations. Boston allowed just 57 shot attempts, eight shots on net, five scoring chances and only one high-danger chance while shorthanded. Those are incredible numbers against an elite unit that features arguably the best power-play goal scorer of all time in Ovechkin.
Even though the Bruins had the second-best penalty kill percentage in the regular season, the Capitals power play enjoyed pretty good success against that unit. Washington tallied more shot attempts, shots on net, scoring chances and goals against the Boston PK than any other East Division team during the regular season. So it wasn't like the Capitals lacked confidence with their power play entering the series.
"We talked about that before the series -- they're a great power play. They kind of had our number in a way, we've had a good PK all year but they are a good power play and during the year they scored some pretty big goals for them," Bruins center Patrice Bergeron said following Game 5.
"We knew we had to come up big. We could maybe do a better job staying out of the box, but every time our PK was out there I thought it gave us momentum to carry on with the game. It was great to see."
The Bruins do need to stay out of the box going forward. If the Pittsburgh Penguins are the B's second-round opponent, Boston's penalty kill will have another tough matchup on its hands. Sidney Crosby, Evgeni Malkin and Kris Letang headline a very talented Penguins power play.
One of the strengths of this Bruins team for most of the last decade has been the penalty kill, and that's clearly still the case entering Round 2 of this year's playoffs. The Bruins have been an elite 5-on-5 team after the April 12 trade deadline, so if they can frustrate opponents and hold them off the scoreboard while shorthanded, the chances of Boston making a deep postseason run will significantly increase.