One thing about team CORSI that doesn't come up enough - or that is not as well explained as a reason to why it isn't THE stat that it is trotted out to be. Whenever there is an exception, the counter-argument is always: "That is what Toronto fans said too. That is what the Avs fans said too" regarding how teams allow perimeter shots.
Take the Flames. A young, less talented team than the contenders out there. No one is arguing against that (though I would argue they aren't quite as unskilled as most people keep stating in the media).
Watch their systems play in the defensive zone. They sit back a bit more. They are more patient in the defensive zone than a lot of other teams. It seems to me that Hartley has it drilled into them that once the opposing team has gained the zone, the team plays more of a positional defence. Sure, they do pressure the puck carriers a bit, but not as much as other teams.
Compare that to the Wild. They are very, very aggressive in the defensive zone. They don't give a team time or space out there. Without looking, I would just guess that the Wild have better CORSI stats as a team.
Consider Edmonton with their 'swarm' defence. Remember when they were losing and all those 'this guy scored' pics? Well, they really pressured the puck carrier, but didn't pick up any trailing men. They had great CORSI stats then if I remember, even though they were giving up golden opportunity after golden opportunity, and were rarely in a situation that someone could point and say: "They controlled the game, and they lost out of sheer bad luck."
I think where CORSI really becomes valuable is when you are comparing individuals on the same team. Same system (for the most part - the coach will obviously utilize guys a bit differently, and often there is a set play involved), same team, same season. You can see which players on your team further impact the team other than the regular stats page, or scoring chances. I think it is a wonderfully useful tool to compare players amongst themselves on the same team, and see where perhaps players should be facing lower quality of competition (sheltering) or players that perhaps you can trust against better competition.
I am just not sold on the team CORSI, as there seems to be too many exceptions. Calgary has been an exception all season long. Colorado was a huge exception last year - even winning the division. I am not convinced that CORSI was predictive in their collapse. Perhaps it was the roster changes that impacted the team more severely (losing Statsny, who I think was their best FO guy, and someone who seemed to be utilized like Backlund when they moved ROR to wing) hurt them more than helped. Maybe Varlamov is having a down year, and based on how relatively inexperienced their defensive corps are, that would have a big impact. Perhaps Roy has been trying to adjust how their team plays this year and tinkering with the systems. Perhaps the team is tuning him out a little bit?
Maybe it was predictive after all. I just don't see why it is some kind of a law. Leafs plainly sucked out there and were a poorly built team that was much like Calgary for the few years before the blow-up - constantly would go on many ups and downs, and most nights seemingly playing with half-effort.
As the OP pointed out, Anaheim has been a good exception as well to CORSI.
I can't say that the Flames won't regress next year. If they do, it is not because CORSI predicted it. I would bet it would be due to changes on the team somewhere. Maybe Treliving will demand a tighter defensive system much like Sutter did for Keenan. Maybe the roster moves that they will make will change the chemistry too much. Maybe Hartley will have players start tuning him out. Who knows... but it just seems like in a 30 team league, the amount of outliers is too great to have anything other than a casual correlation at best
Generally, yes, there is somewhat of a correlation with taking shots on net and winning a game. You can't win games if you don't take shots on net. What it continues to ignore is scoring chances (subjective) and quality of shots (again, shots from the slot = shots from the red line). The confidence level should decrease significantly, no?
CORSI (in my opinion) should be broken down into categories. Shots from the slot. Shots from the point. Shots of greater than 60 degrees. 2nd shots. 3rd shots. Shots through traffic. Etc... Sure, this is all way more difficult to calculate, but it would really be much more predictive.
But then again, a team will switch its' roster in the off-season, change up its' systems, and you would be left with a fairly different team on that stats paper. Even goalie save percentages can differ so much. Just look at Kipper's save percentages over the years. Look at Dubynk. Also, players themselves regress or improve. Players play through injuries, players become healthy, players are sometimes overly-favored by the coaches (and this is where advanced stats should really help to guide coaches here) or unfairly disliked by the coaches.
I like stats in sports. I believe they absolutely have a place moving forward, and it is yet another thing to look up and compare between players and teams. I just think they are in their infancy. It also seems like a lot of teams don't put a whole lot of stock into what we as fans are following in terms of statistical information, and have their own 'secret' stats that they utilize that are not only much more useful, but probably much more predictive.
Some stats guy wrote a nice post in one of the Flame-bashing threads on how the confidence interval was so low for CORSI, that he would be fired if he submitted work like that to his boss. He was a statistician of some sort. I was more or less sold on these current advanced stats right up until his post where he just ripped them apart. I should have saved it. If there are any statisticians on this forum (more than just guys like me who have had to take a couple of stats courses as part of their program, but guys who have majored in actuarial science), I am sure they could come up with an even better rebuttal to all things CORSI, PDO, and perhaps a few other ones that are being utilized. It is way beyond me.
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