Sorry, but every metric (as well as actually watching it) says it is night and day with him on it as opposed to off. Even using Corsi, only he and Bailey have been remotely good on the PP this season:
CF% on PP:
1. Bailey (2:00 minutes) 7.8
2. Oliver Wahlstrom 7.6
None of the other players with a minute or more average ice time are above 5.
And I didn't just use PPP/60 (which isn't flawed by any means as long as you are getting ice time)- but I also used the fact that HE HAS PERSONALLY BEEN ON THE ICE FOR HALF OUR POWER PLAY GOALS and considering he is EIGHTH among forwards in PP ice time, that too speaks volumes.
Collectively, when you put all that together it isn't exaggeration or labeling him a savior by any means (especially when he DOES NOT HANDLE THE PUCK- WHICH IS OUR #1 PROBLEM- INCLUDING THE ENTRY) but it is absolutely factual we are much much better with him on it....
I think we're talking past each other so I'll try to clarify as best I can.
The New York Islanders power play is bad, it's 18.8% on the season and is ranked 21st in the league. After Wahlstrom's initial boost to the power play (until the end of February) the power play has operated below that 18.8% until April 23 (I didn't look up any stats after that).
Whether or not Wahlstrom is the best option to be on the power play isn't something I'm debating. He should be on the power play. I'm saying, and the stats support, that the power play is not more effective (read: converting at a higher percentage) when he's on it than when he's not.
You're using all of these proxies for production instead of just looking at the PP% during the games in which he plays and is given ice time. Is it good that the PP gets more shots when he's on the ice? Yes. Is it good that he's producing points with the ice time he's been given? Yes. Does that make the power play better as a whole because he's on it? No, it does not. There is no meaningful difference between the success rate of the power play when he's on it verses when he's not (up until that April 23 date).
The reason PPP/60 is or any /60 stat is flawed is because it's treating all minutes as the same, which just isn't the case. There are some players who can continue their point production when given more minutes and there are some players who can't. I also don't care what his production is on the power play, I care whether the power play is actually going to score. Whether that's Bailey, Wahlstrom, or they're shooting the puck off Brian Strait's head in the press box, it's irrelevant who is scoring the goals.
Edit: To piggyback off our previous conversation and how I broke down the season into different stretches (mostly 8 game ones).
From 4/3-4/18 the team played in 8 games, Wahlstrom played in all of those games. The team's PP was at 8.3% over those games. He then sat out for the next 3 games 4/20-4/24, the PP was 42.9% during that short stretch. Wahlstrom played the final 8 games and the PP was 21.4%. There hasn't been much of a correlation between Wahlstrom playing and the team succeeding on their power play chances.
From March 1 until the end of the season the PP% is 14.3.