Rather than gradually work my way back in time, I thought it best to just jump straight back to the first possible year to calculate PDO: 1983-84.
It was a different time. The season began with Bonnie Tyler’s “Total Eclipse of the Heart” at the top of the charts, soon to be knocked off by “Islands in the Stream”. Martin Luther King Day was officially declared a national holiday. Able Archer 83 unknowingly brought the Soviets and Americans to the brink of WWIII. And the NHL finally began tracking shots against, allowing for retroactive PDO.
In the write-up I did on PDO in the first place, I noted that:
- An all-situations PDO higher than 100.9% very strongly correlates to a playoff appearance
- A PDO below 99.2% very strongly correlates to missing the playoffs
- PDO has little predictive value in the playoffs, although I pointed out that further research would be needed.
The following table shows each team’s all situation PDO in 1983-84. The key numbers are on the right: “PDO” is the original number I had without taking the empty net goals into account, and “AdjPDO” is the big number that has everything properly balanced and comes out to a leaguewide total of 100.0000000000. SV% is the total number of goals against from number of shots against; TmSV% includes the empty net shots (which had to be adjusted for). In this table, AdjPDO is simply S% plus TmSV%.
The first thing to note is that there are only six teams inside the 99.2%-to-100.9% range at all. I believe this to be a symptom of a significantly unbalanced league, one which saw just five teams finish within 10% of .500. There were also five 100-point teams, meaning that in a 21-team league there were as many teams that finished with 100+ points as finished anywhere between 72-88.
In the Campbell Conference, exactly three out of ten teams finished above .500: Calgary at 34-32-12, Minnesota at 39-31-10, and Edmonton at 57-18-5. Both Minnesota and Calgary would have missed the playoffs if they had been in the Patrick Division, and either one would have been the #4 seed in the Adams.
However, we must still see if PDO had any predictive value at this time despite the divisional playoff system and the unbalanced league.
In the first round:
- Montreal (lower) defeated Boston (higher)
- Quebec (higher) defeated Buffalo (lower)
- NY Islanders (higher) defeated NY Rangers (lower)
- Washington (higher) defeated Philadelphia (lower)
- Calgary (higher) defeated Vancouver (lower)
- Edmonton (higher) defeated Winnipeg (lower)
- St. Louis (higher) defeated Detroit (lower)
- Minnesota (higher) defeated Chicago (lower)
That’s 7-1 in the first round for the higher PDO team. And of these, despite the lack of overall competitive balance, only two series involved a massive disparity in team points that season: Edmonton finished 46 points ahead of Winnipeg and swept them, and Boston finished 29 points ahead of Montreal but were themselves swept.
In the second round:
- NY Islanders (higher) defeated Washington (lower)
- Montreal (lower) defeated Quebec (higher); this was the series that featured the infamous Good Friday Massacre
- Edmonton (higher) defeated Calgary (lower)
- Minnesota (higher) defeated St. Louis (lower)
That’s another 3-1 for the higher team.
And the rest of the way:
- Edmonton (higher) defeated Minnesota (lower)
- NY Islanders (higher) defeated Montreal (lower)
- Edmonton (higher) defeated NY Islanders (lower)
All in all, that’s a shocking 13-2 overall record for the higher PDO team in each playoff series.