Corsi WOWY, part 2: ?-Nielsen-Hunter

Editor's Note: Further examination of the Nielsen Effect courtesy of BenHasna.

A few interesting questions have been brought up following part 1 of my Corsi WOWY analysis, such as why do Sean Bergenheim and Frans Nielsen seem to work not nearly as well together as Trent Hunter and Frans Nielsen? Or who might benefit most from playing LW on a line with Nielsen and Hunter?

Although we won't find all the answers, I'll try to give a better idea and will look more closely at the numbers of Hunter and Bergenheim. Again, in case you'd like to know what this is all about, please check part 1, where I praised Nielsen almost as much as Dom normally does.

To tell which left winger worked best with those two is more difficult than just looking at the numbers of one single player. Generally, these numbers only tell us whose Corsi ratio benefited or suffered from playing with or without a certain other player. But they don't tell anything about how well whole line combinations worked. By combining a few numbers or remembering certain things from watching the games, we should still get a pretty good idea. But it's definitely a bit more vague. I'll give it a try, but not sure if my reasoning makes any sense and I'd surely welcome any comments.

By the way, over at the Cult of Hockey, there's an interesting interview with Jim Corsi about how it all started and what he thinks about "his" number. 

Let's check the facts first, thus the numbers of Trent Hunter. The table again includes all players who had at least 100 Corsi events in total (Even strength, excluding empty-net situations) while being on the ice together with Trent Hunter. It corresponds to the 2nd table in part 1 and therefore always has to be read from Hunter's point of view. For example, Hunter was on the ice together with Nielsen for 676 Corsi events in total. 0.558 of these 676 (377) were in the Isles' favour (299 were against them). But only 0.490 of the 782 Corsi events when Hunter was on the ice without Nielsen were in the Isles' favour. Hunter's Corsi ratio is 13.77 % higher with Nielsen than without him.

As said, my focus isn't on Hunter's numbers solely, but they surely are pretty impressive, too. They're much more difficult to interpret than Nielsen's numbers, though, as Hunter played against tough competition sometimes, but also had easier shifts in more offensive lines (together with Tavares and Schremp mostly). In addition, he takes as many shots himself as no other forward on this team. I don't know how much that affects these numbers, though. Generally, Corsi does a good job of telling which team dominates territorial play and creates more scoring chances. But I guess one single player does indeed get better or worse opportunitites on average per shot than certain team mates. Hunter actually often seems to gain the zone and pretty quickly shoot the puck from far out, which helps his Corsi, but perhaps not so much his scoring chance differential. He's not creating danger by taking a shot as much as maybe Moulson, Comeau or others. But as said, no idea really, how big of an impact that has. I'd be careful here and not praise Hunter too much just from looking at these numbers.

It's Bergenheim...

Anyway, I'm looking at Hunter's numbers mainly to find out who might have worked best with him and Nielsen at center. In order to get a better idea, let's get their numbers together and look at the wingers Hunter played with. I didn't include Bailey, as more than half of Hunter's time together with Bailey was when Bailey played center and thus obviously without Nielsen. 

Sim and Tambellini obviously can't be the best fits, as they both hurt Nielsen as well as Hunter's numbers quite a bit. It can't be Joensuu, either, as he played almost never with Nielsen. His shifts together with Hunter were centered by Schremp mostly and that trio seemed to do well indeed, but also played against relatively weak competition, I guess. It's Moulson or Bergenheim therefore. I don't think we'll be able to conclusively say who it is, but I'll do some more guesswork.

About one fourth of Hunter's shifts with Moulson were centered by Tavares, three fourths by Nielsen. Overall, Hunter and Moulson had a Corsi ratio of 0.522 when playing together. Now, in order to find out how high that ratio might have been, when they additionally played with Nielsen, we have to sort out the Moulson-Hunter shifts centered by Tavares. That's possible here, because Moulson was the only LW used in a line centerd by Tavares with Hunter at RW. We can see that from checking Hunter's time for line combinations with Tavares. As we can see in table 1, Hunter had a ratio of 0.493 together with Tavares, which therefore actually is about the ratio the whole line of Moulson-Tavares-Hunter had. To get to their overall ratio of 0.522, Hunter and Moulson therefore must have done better when centered by Nielsen. As three fourths of their shifts were centered by Nielsen, the ratio of Moulson-Nielsen-Hunter probably was a tad above 0.53.

If we do the same for Bergenheim's time with Hunter, we find that they were used together almost only when Nielsen was the center. So, the Corsi ratio of Bergenheim with Hunter (0.560) gives us a pretty good idea what the whole line of Bergenheim-Nielsen-Hunter actually did. 

Bergenheim-Nielsen-Hunter (about 0.560) therefore did a bit better together than Moulson-Nielsen-Hunter (0.530). But remember, part of this is already guesswork and this still doesn't mean Bergenheim-Nielsen-Hunter had perfect chemistry together. We'd still need to check these combinations for who they were on the ice against, where their shifts started and generally when they were used (mostly at home, during a good run of the whole team, etc.). Here, it wouldn't make sense if Bergenheim-Nielsen-Hunter were used in easy situations only, though. They're all three defensively responsible and probably achieved their good ratio against quite tough competition indeed. So, yeah, I'd say they were pretty impressive indeed and for sure better than for example Moulson-Tavares-Hunter who I'd guess were used in easier situations, but still only managed a ratio of about 0.493 together.

...surprisingly

We found in part 1 that Bergenheim and Nielsen didn't put up very impressive numbers together. And now it seems Bergenheim and Nielsen were (together with Hunter) part of one of the more convincing lines the Islanders used this season. How is that possible? Well, Bergenheim's other shifts together with Nielsen must have been quite mediocre. As we can see from checking Bergenheim's time for line combinations centered by Nielsen, only about one fourth of the time was together with Hunter. Another fourth was together with Sim and about half of the shifts were together with Okposo. Let's take a closer look therefore at how Sim and Okposo respectively did with and without Nielsen and Bergenheim.

As particularly Bergenheim-Nielsen and Nielsen-Okposo were used in so many more combinations, it's impossible to do the same as above and sort out the results for single line combinations. But it definitely looks like Bergenheim-Nielsen-Okposo as well as Bergenheim-Nielsen-Sim might have Corsi ratios below 0.500. As for Bergenheim-Nielsen-Okposo, that's nothing worrying, as they surely were used in the toughest situations you can imagine and after all probably even worked pretty well together. Bergenheim-Nielsen-Sim might also have had a few difficult shifts, but there's no way we'd expect this line to do significantly worse than other combinations centered by Nielsen. So, that line probably simply didn't work very well indeed.

Finally, it looks like Bergenheim's numbers with Nielsen suffered because of mainly two things. First of all, the toughest situations they were used in together (mainly with Okposo at RW) and then the fact that Sim was their RW for a good part of their shifts.