Tyler Dellow got to to the root of the Oilers' problems on the power play and came to the conclusion that it was all about the zone entries:
I made notes as I was doing this as to who attempted to enter the defensive zone on the PP for the Oilers and, while my notes aren’t perfect, it looks like this is more of an issue with the putative first PP unit, with a core of RNH-Hall-Eberle-Schultz than it is for the Hemsky-Gagner-Yakupov grouping. Nothing precise but the second unit looks to be about 10% more likely to gain the zone than the first unit which roughly fits with what my eyes have been telling me. The first unit looks to me to be a bit more out of sync and a bit less likely to bring some trickery to play – they’re big fans of letting Hall wind up around the Oilers blue line and roar into the teeth of the defence. The second unit’s a bit more likely to use varied pace and puck movement to try and create an opening.
By his eye, the Hemsky / Gagner unit is not struggling as much as the Hall / Hopkins / Eberle unit and the numbers back his eye up. Below are two tables containing the shot and shot attempt rates of the top two power play combinations while on the ice:
Note how much better the second unit measures up by this metric:
But with missed shots added in, there isn't any separation at all.
98 forwards have played five games and an average of three minutes or more of 5v4 time. Jordan Eberle ranks 86th in shots for /60, while Ryan Nugent-Hopkins ranks 85th. Taylor Hall has an ever-so-slight edge on those two at 78th. The worst of the second line by this metric, Sam Gagner, ranks 73rd. Nail Yakupov ranks 67th, while Ales Hemsky has distinguished himself from the entire group at 53rd.
Add in the missed shots, and Taylor Hall is the highest-ranked Oiler at 74th and Gagner is lowest at 92nd. But for now, the Yakupov / Gagner / Hemsky unit is carrying the Oilers - they are scoring twice as often as the first unit. No one should expect that conversion rate to continue.
With the knowledge that shots per 60 predict 40% of power play success, and the continued struggle the Oilers have with shots on goal on the power play (they rank 27th this year), the need to fix the zone entry problem and get more pucks to the net is paramount, probably equal to the need to fix the defensive depth problem. Ralph Krueger can't fix the roster deficiencies, but he can certainly solve the structural deficiencies with a man advantage.