Prior to the start of the 15-16 season, Matt Cane published an article on Hockey-Graphs arguing why teams should use four forwards on the power play rather than the standard 3 forwards 2 defensemen set up. Cane's findings were such that power plays with the unconventional set up shot the puck more and scored more than the traditional set up. Consequently, four forwards also allowed more shots, and their goalies had a lower save percentage (suggesting that these shots against were also more dangerous). Further research showed that the goal differential from scoring more tended to outweigh these new dangers. Give the full link a click, it's a great read.
I returned to this article earlier in the week after laboring over the Rangers current personnel set up. The top-7 defensemen on the Rangers currently shape up as McDonagh, Klein, Staal, Holden, Skjei, McIlrath, and Girardi. Of this crop there is one player who has seen power play time consistently, and that is McDonagh. Klein and Holden can spot-duty. Skjei is an unknown, but I'd imagine the Rangers have eyes on him taking on that role this season. Such is life for the Rangers. Adapt or die.
With that set up, it would be in the Rangers best interest to let McDonagh play on the first PP unit, and allow whoever wins the spot between Holden, Skjei, and Klein to play on the 2nd unit.
Like the teams that Cane researched in the Hockey-Graphs article above (seriously, read it, it's great) the Rangers of 2015-2016 were a more dangerous power play when running a power play with only one defenseman.
In terms of pure numbers, when running a PP with one defenseman, the Rangers scored 21 goals and allowed 2 (90%); they generated 321 shots, and allowed 34 (89.4%). When running a PP with two defensemen, the Rangers scored 17 goals and allowed 2 (89%); they generated 309 shots and allowed 42 (88%).
[what I don't have here that is a hindrance to this analysis is TOI splits between 1-dman power players and 2-dmen power plays. Considering how close the total shots are though, I'd imagine the splits are at or near 50/50 with a slight lean towards 2-dmen power plays as research has shown that 1-dmen power plays produce shots at a greater rate per 60]
My real takeaway from this analysis though, is that the Rangers were much more dangerous when they used only 1 dman (proven by the 6 more goals).
To display the difference in danger of shots, I'm using corisca.hockey's expected goals, and applying a visualization that I saw Stephen Burtch use on Twitter.
What I really want to detail here is the long-tail that the 1-dman chart has. With one defenseman on the ice, the Rangers were able to generate shots (unluckily no goals) with an expected goal rating of over 0.4 - which did not occur a single time with two defensemen on the ice.
Chris Kreider seemed to be a major contributor to the Rangers bad luck last season, having 3 of the Rangers 7 most dangers shots on goal with a 1D power play, and scoring on none of them.
In the spirit of fairness, I also wanted to post density charts for shots against for each situation, but since there are only 2 goals for each, it's not cooperating, so here are screenshots of the top-5 most dangerous shots against the Rangers with 1-dman and 2-dmen on the ice during a power play.
It's time to throw out the conventional thinking, that having only 1 defenseman on the point during the power play opens the team to potentially too many high-danger chances against. Certainly, against teams that may have prolifically fast PKs, maybe you want two d-men back there for safety; but in reality, the PP isn't the time to play it safe.
The Rangers have enough firepower up front (as currently constructed) to use 8 different forwards on their power plays.
Might I suggest:
Kreider - Stepan - Nash
Zuccarello - McDonagh
Miller - Hayes - Buchnevich
Zibanejad (trigger man, top of the circle, Ovechkin's spot) - Skjei
Play four forwards on the PP, coach.