“Essentially if a winger is out for a lot of shots at net against — with ZoneStarts and QualComp being equal — what his Corsi-minus tells us is mainly whether he’s out with a weak center and defencemen.”

Maybe. But it might also mean that he is woefully bad at winning the puck battles in the corners in the offensive zone resulting in the opposition being able to recover more pucks and transition to offense easier and more frequently. I don’t think we can reasonably and fairly assign blame for poor corsi or poor goal stats because there is so much happening on the ice which may not be apparent if we just look at the direct cause of the shot or goal.

“Travis Moen or Scott Gomez would likely have a closer to average team shooting percentage when they are playing on the ice if they were to play a more offensive role.”

‘Average’ is still a long way from where Sidney Crosby is. Oh, and Gomez generally speaking has played an offensive role on his team.

“Nobody is arguing that scott Gomez and Sidney Crosby are equals offensively – except you so you can argue against it. ”

You indirectly are but you won’t admit it. Crosby’s 4 year FenF% is 0.534 and Gomez’s is 0.534. Perfectly identical. Gomez has more OZone starts too so that would seem to indicate over the prior four years that Gomez was given a more offensive role. So how do I make Crosby look better than Gomez using corsi stats?

You are making a ton of theoretical arguments without any numbers to back them up that don’t apply in practice.

Corsi is an OK proxy for scoring chances, I agree with that notion.

But even if we know who is out on the ice for scoring chances for and against, if we’re to be fair and accurates to the players we evaluate, it’s crucial to know who was actually involved in creating these scoring chances for and in making mistakes on chances against.

It’s not right to blame a dman for a scoring chances against if he made no mistake on the play. Nor is it right to give credit to a forward, if he had no impact on creating a scoring chance for this team.

But that’s typically what is done when people apply Corsi/scoring chance team metrics to individual players. For some reasons it’s assumed that players really deserve all those plus marks and minus marks, and that is solid data, when it’s not really close to that.

Wingers, for example, have fewer defensive responsibilities, more offensive responsibilities. That means it’s far less likely they will be involved in chances for. They very often deserve those plus marks on scoring chances for.

But they very often don’t deserve the minus marks on chances against.

Yet when team Corsi and scoring chance numbers are applied to individual players, the individual gets a plus for all chances for and a minus for all chances against no matter what they did on the play.

The stat is utterly riddled with false negatives and false positions.

And, no, it doesn’t always “even out” over a full year of play. Why should it?

There are cases of good players playing with crappy linemates pretty much all season long, and also cases of bad players playing with good linemates pretty much all season long.

So while Corsi plus/minus might often get it right on players, it’s the exceptions that really cause problems if you’re relying on it to rate individuals (as many bloggers do and maybe even some NHL GMs do, for all I know).

Essentially if a winger is out for a lot of shots at net against — with ZoneStarts and QualComp being equal — what his Corsi-minus tells us is mainly whether he’s out with a weak center and defencemen.

Try making NHL trades based on Corsi, factoring in all the other stats you want. You will make a small number of terrible trades based on Corsi plus/minus, because it’s not a reliable indicator of two-way play.

So if bloggers won’t to keep using Corsi plus/minus to rate the two-way play of players, they’re free to do so, but don’t expect the majority of the hockey world to embrace these numbers.

At best, it’s somewhat unfair and inaccurate to apply a team plus/minus number to an indvidual player. It makes me uneasy.

Travis Moen or Scott Gomez would likely have a closer to average team shooting percentage when they are playing on the ice if they were to play a more offensive role. Of course Moen especially would not likely be too successful a player in that role regardless of his team’s shooting percentage.

Nobody is arguing that scott Gomez and Sidney Crosby are equals offensively – except you so you can argue against it. That is another reason you are treated as such a pariah on the internet. You misrepresent everyone else’s arguments. You would be well advised to stop that.

I understand perfectly what you are saying. I just think it is complete and utter nonsense. Would Travis Moen’s (or even Scott Gomez’s) on-ice shooting percentage jump from bottom of the league to top of the league if his coaches just asked him to play more offensively? When you can prove that to me I’ll accept what you are saying, until then you just look like some idiot arguing that Scott Gomez is as good offensively as Sidney Crosby if only he played under more favourable wind conditions.

By that I mean you are suggesting that we should ignore that players have elevated on-ice shooting percentages because they only got elevated on-ice shooting percentages because they tried to get elevated on-ice shooting percentages and we shouldn’t credit players for trying.

Oh, BTW, the Red Wings try and play a puck control game. That is the style of game the coach asks them to play. Should we ignore their strong corsi ratings because they tried to get a strong corsi rating?

The analogy I have tried to use to explain it to him is wind. Wind causes trees to move. David is arguing that trees moving cause wind. He wastes a lot of time measuring that it is windier near his apple tree than his pear tree thinking that proves his point. All it proves is that his apple tree is in a windier location. It didn’t cause the wind.

The idea that PDO regresses to 1000 is clear. Obviously that number isn’t exactly one for all players, but it is a very good rule of thumb. Just like the rule of thumb that all the trees in your yard get the same weather.

The Ovechkin point made by Neil Greenberg is a valid one. He is showing that Ovechkin’s lack of scoring this year is not explainable by bad luck. He has a valid point and PDO shows it well.

Players do not drive the shooting percentage of their teammates and opponents who are on the ice while they are. At least not to a very significant level.

Stop wasting your time on this point.

You found that players who get hardly any ice time are not used in offensive situations and hence do not get high percentage shots, while players who get lots of ice time often do play in a significant number of offensive sitautions. The situation drives the shooting percentage.

If you put three career 11% shooters on a line and they all continue to shoot at 11%, no one is driving the shooting percentage, they’re all just performing at their true talent level. Now, if you put three career 11% shooters on a line together and two of them became 15% shooters (over a large enough sample size), then *that* would be evidence of players “driving shooting percentages”.

You continue to construct strawman arguments to knock down that few if any people actually believe.