If you had to guess, what would you say was the best PP unit of all-time? Surprisingly, it's the New York Islanders - before they rattled off their string of four Stanley Cups. With Bryan Trottier, Mike Bossy and Clark Gillies up front, and Denis Potvin and Stefan Persson on the blue line, the Isles put away nearly 30% of their power-play opportunities over a six-year period:
| Year | Team | PP% |
| 1977-78 | Montreal Canadiens | 31.88 |
| 1975-76 | New York Islanders | 31.72 |
| 1977-78 | New York Islanders | 31.28 |
| 1978-79 | New York Islanders | 31.15 |
| 1973-74 | New York Rangers | 29.73 |
| 1980-81 | New York Islanders | 29.34 |
| 1982-83 | Edmonton Oilers | 29.25 |
| 1979-80 | Montreal Canadiens | 29.17 |
| 1969-70 | Boston Bruins | 29.03 |
| 1971-72 | Boston Bruins | 28.91 |
| 1973-74 | Boston Bruins | 28.89 |
| 1972-73 | Philadelphia Flyers | 28.79 |
| 1974-75 | Boston Bruins | 28.76 |
| 1975-76 | Philadelphia Flyers | 28.62 |
| 1987-88 | Calgary Flames | 28.46 |
The Orr-Esposito-Bucyk Bruins of 1969-75 were almost as good as the Isles. The late 1970s Canadiens dynasty makes a couple of appearances - unlike the Islanders and the Bruins, the Habs rolled two power-play units. Stanley Cup-winning Oilers, Flyers and Flames squads also show up.
What if we adjust teams relative to the league-wide PP%?
| Year | Team | PP% | REL LGE |
| 1973-74 | New York Rangers | 29.73 | 55.74 |
| 1975-76 | New York Islanders | 31.72 | 54.43 |
| 1972-73 | Philadelphia Flyers | 28.79 | 53.87 |
| 1973-74 | Boston Bruins | 28.89 | 51.34 |
| 1977-78 | Montreal Canadiens | 31.88 | 50.73 |
| 1971-72 | Boston Bruins | 28.91 | 49.17 |
| 1969-70 | Boston Bruins | 29.03 | 49.10 |
| 1972-73 | Boston Bruins | 27.8 | 48.58 |
| 1977-78 | New York Islanders | 31.28 | 47.90 |
| 1970-71 | Boston Bruins | 27.68 | 47.00 |
Interestingly, our top teams don't move around very much - what these teams have in common is that they all played during an era of massive talent dilution and little player movement. Montreal, Boston, New York and Philadelphia were all able to concentrate talent in a way that would be unthinkable today and use that advantage to dominate the weakest entries in the NHL. While you can put together a truly bad team any time you want, it is simply no longer possible to build teams that are this much better than their opponents.