So I had a theory today that the more power play opportunities per game, the higher the PP% would be because the more PP opportunities, the more "practice" to fine tune your power play.

I was wrong. The yellow and line blue lines tell it all. There doesn't seem to be any sort of correlation between # of PPO and PP%. I guess that's because it works both ways: The more "practice" your power play gets... the more "practice" the other team's penalty kill gets. It almost looks like there's a correlation. It seems almost as if the OPPOSITE is true; that the more opporunities the lower the %... but I think the PP% is more linked to the SV% than anything else. Although..   maybe there is a correlation. Maybe the more PPO per game, the worse the PP% because the more you get the lazier you get. I don't know. It would be nice if hockey reference has a stat for power play shots and power play saves.. then we could open up a whole other can of crazy and really analyze the power play.

As expected, as the SV (line at the top) slowly gets better, the ultimate trend of the PP% is going down... just more proof that your goalie is your best penalty killer. What's weird though is that even though SV% has gone through the roof (it's up to a league avg of 9.11 now) , the PP% seems to be on the rise.

Here's the one REALLY interesting thing I noticed. Yes, the Power Play goals per game has the same overall trend as total goals per game (the both go down and up at the same time as expected).. however the power play goals haven't gone down anywhere NEAR as much as total goals per game.. in other words.. over time the power play goals have made up a much higher % of the team's overall goals. 

Proof.... Live by the power play... die by the power play.