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Forums :: Blog World :: Bill Meltzer: Meltzer's Musings: Trial on the Isle, Quick Hits
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Just5
Philadelphia Flyers
Location: PA
Joined: 05.22.2008

Jul 14 @ 11:10 PM ET
The emergence of Hedman as a top defenseman really makes that team.
- MJL


No question. And he was a huge question mark just 2 years ago
Tomahawk
Location: Driver's Seat: Mitch Marner bandwagon. Grab 'em by the Corsi.
Joined: 02.04.2009

Jul 15 @ 12:02 AM ET
Regardless, Getzlaf doesn't make Tomahawk's list, because he prefers players who score highly on possession stats. And that's his opinion and preference.

So that's that.

- Giroux_Is_God



Getzlaf is a good possession player, but I didn't pick him b/c he's not very mobile and he also skirts the top of the "young" qualification that was originally put forth.

Duchene I would have included in my top-15... just ran out of spots.
Tomahawk
Location: Driver's Seat: Mitch Marner bandwagon. Grab 'em by the Corsi.
Joined: 02.04.2009

Jul 15 @ 12:48 AM ET
I think Tomahawk can speak for himself. Getzlaff was 2nd only to Sidney Crosby in the entire League at ES points. Which matters far more then a flawed possession number.
- MJL



Aren't points a similarly imperfect way of isolating individual player contribution?

Doesn't it take all five guys to move the puck up the ice and put the team in a position to score? Isn't there an inherent flaw in the way goals and assists are doled out? Are all goals and assists earned? Aren't there plays/passes that make goals possible that aren't credited as points? Isn't it also true that points are highly dependent on position, tactics, usage, time spent on the PP, linemate quality, team SH%, line matchups, team schedules, etc?

If so, don't we have to stop using points to valuate players because they're not perfect in their ability to gauge a player's contributes in relation with other players?

Of course not.

Points are still a perfectly good, albeit imperfect, indicator of worth... we just have be mindful to provide a little background and/or context along with the number... as most people are in the habit of doing when presenting perfectly good, albeit imperfect, possession numbers.

Giroux_Is_God
Philadelphia Flyers
Location: CLASS DISMISSED
Joined: 12.15.2011

Jul 15 @ 1:11 AM ET
Aren't points a similarly imperfect way of isolating individual player contribution?

Doesn't it take all five guys to move the puck up the ice and put the team in a position to score? Isn't there an inherent flaw in the way goals and assists are doled out? Are all goals and assists earned? Aren't there plays/passes that make goals possible that aren't credited as points? Isn't it also true that points are highly dependent on position, tactics, usage, time spent on the PP, linemate quality, team SH%, line matchups, team schedules, etc?

If so, don't we have to stop using points to valuate players because they're not perfect in their ability to gauge a player's contributes in relation with other players?

Of course not.

Points are still a perfectly good, albeit imperfect, indicator of worth... we just have be mindful to provide a little background and/or context along with the number... as most people are in the habit of doing when presenting perfectly good, albeit imperfect, possession numbers.


- Tomahawk

10/10
Jsaquella
Philadelphia Flyers
Location: Bringing Hexy Back
Joined: 06.16.2006

Jul 15 @ 1:25 AM ET
Aren't points a similarly imperfect way of isolating individual player contribution?

Doesn't it take all five guys to move the puck up the ice and put the team in a position to score? Isn't there an inherent flaw in the way goals and assists are doled out? Are all goals and assists earned? Aren't there plays/passes that make goals possible that aren't credited as points? Isn't it also true that points are highly dependent on position, tactics, usage, time spent on the PP, linemate quality, team SH%, line matchups, team schedules, etc?

If so, don't we have to stop using points to valuate players because they're not perfect in their ability to gauge a player's contributes in relation with other players?

Of course not.

Points are still a perfectly good, albeit imperfect, indicator of worth... we just have be mindful to provide a little background and/or context along with the number... as most people are in the habit of doing when presenting perfectly good, albeit imperfect, possession numbers.


- Tomahawk


SuperSchennBros
Location: Not protected by the Mods...I mean Mob. Take your best shot!
Joined: 09.01.2012

Jul 15 @ 1:57 AM ET
Getzlaf is a good possession player, but I didn't pick him b/c he's not very mobile and he also skirts the top of the "young" qualification that was originally put forth.

Duchene I would have included in my top-15... just ran out of spots.

- Tomahawk

Sweet Jesus, are you guys still talking about this?

Let's not forget that Crosby and Getzlaf did play together on the same World Junior Championship team.

1. Crosby
2. Malkin
3. Stamkos
4. Giroux (Yes I think he's that good)
5. Tarvares
6. Toews
7. Kopitar (Low on my list because I feel he has a lot of help)
8. MacKinnon
9. Duchene
10. Nugent-Hopkins
Giroux_Is_God
Philadelphia Flyers
Location: CLASS DISMISSED
Joined: 12.15.2011

Jul 15 @ 2:31 AM ET

- Jsaquella


Dodgeball. What a classic.
wilsonecho91
Season Ticket Holder
Philadelphia Flyers
Location: A dream to some...a nightmare to others, AK
Joined: 11.13.2007

Jul 15 @ 2:40 AM ET
10/10
- Giroux_Is_God


Deduct .5 for the term "valuate."
MJL
Philadelphia Flyers
Location: Candyland, PA
Joined: 09.20.2007

Jul 15 @ 7:57 AM ET
Aren't points a similarly imperfect way of isolating individual player contribution?

Doesn't it take all five guys to move the puck up the ice and put the team in a position to score? Isn't there an inherent flaw in the way goals and assists are doled out? Are all goals and assists earned? Aren't there plays/passes that make goals possible that aren't credited as points? Isn't it also true that points are highly dependent on position, tactics, usage, time spent on the PP, linemate quality, team SH%, line matchups, team schedules, etc?

If so, don't we have to stop using points to valuate players because they're not perfect in their ability to gauge a player's contributes in relation with other players?

Of course not.

Points are still a perfectly good, albeit imperfect, indicator of worth... we just have be mindful to provide a little background and/or context along with the number... as most people are in the habit of doing when presenting perfectly good, albeit imperfect, possession numbers.


- Tomahawk


The percentage of false data involving goals and assists is very small when compared to possession numbers for individual players. Context is only one issue involving possession numbers. That's the big difference. False data is a big issue with individual possession numbers, while it's not with goals and assists awarded. Which makes goals and assists a far more accurate stat indicator of offensive ability for individual players then a flawed stat such as Corsi does to determine possession.
And you know how you realize that a player made a breakout play in his own end that resulted in a goal scored that he does not get credit for in the stat line? Watch the game.
Tomahawk
Location: Driver's Seat: Mitch Marner bandwagon. Grab 'em by the Corsi.
Joined: 02.04.2009

Jul 15 @ 8:29 AM ET
The percentage of false data involving goals and assists is very small when compared to possession numbers for individual players.
- MJL


Are you going to actually provide evidence that this is a mathematical fact, or am I just supposed to take your word for it?

MJL
Philadelphia Flyers
Location: Candyland, PA
Joined: 09.20.2007

Jul 15 @ 9:17 AM ET
Are you going to actually provide evidence that this is a mathematical fact, or am I just supposed to take your word for it?


- Tomahawk



I'll do so right after you provide evidence that refutes my premise of false data involving using Corsi in rating individual players. Which hasn't happened to this point in time from anyone.
This is the typical response of moving the argument away from the facts, to twisting it around to something such as asking to provide evidence, when I've already done so, multiple times, over a long period of time, to support my opinion.

The very fact that goals scored, or even assists is brought up and compared to Corsi, in terms of false data, points to a clear lack of understanding of the stat, and how it is compiled.
Tomahawk
Location: Driver's Seat: Mitch Marner bandwagon. Grab 'em by the Corsi.
Joined: 02.04.2009

Jul 15 @ 9:41 AM ET
I'll do so right after you provide evidence that refutes my premise of false data involving using Corsi in rating individual players. Which hasn't happened to this point in time from anyone.
This is the typical response of moving the argument away from the facts, to twisting it around to something such as asking to provide evidence, when I've already done so, multiple times, over a long period of time, to support my opinion.

The very fact that goals scored, or even assists is brought up and compared to Corsi, in terms of false data, points to a clear lack of understanding of the stat, and how it is compiled.

- MJL


Nobody has ever said that Corsi is perfect... so it's not up to any of us to prove that to you, since none of us believe that to be the case.

On the other hand, you're the one who keeps claiming every advanced stat is false, so isn't the burden of proof really on you now to prove to us that the 'false data' renders the stats useless, when it doesn't for other stats you feel 'matter much more'?
MJL
Philadelphia Flyers
Location: Candyland, PA
Joined: 09.20.2007

Jul 15 @ 10:16 AM ET
Nobody has ever said that Corsi is perfect... so it's not up to any of us to prove that to you, since none of us believe that to be the case.

On the other hand, you're the one who keeps claiming every advanced stat is false, so isn't the burden of proof really on you now to prove to us that the 'false data' renders the stat useless, when it doesn't for other stats you feel 'matter much more'?

- Tomahawk



There is a number of things here that are innacurate. My premise against Corsi is not based on anybody saying it's not perfect. I have stated multiple times that even the developers of Corsi are aware of it's flaws, and how that has to be taken into account when used. But time and again, it's misused to rate individual players.

Secondly, you are also incorrect in stating that I have claimed every advanced stat is false. I've stated repeatedly that I think that Corsi as a team stat is a pretty good stat. Because the issues of false data is removed. Thirdly, I've never stated that the false data renders the stat useless. Only that it is unreliable to rate individual players, but it is again, a good stat, in fact really the only stat and best available to measure possession on a team basis.

And lastly, I have repeatedly not only posted game examples of how the false data is accumalated, but also have provided articles from reliable sources that support my opinion. And I've done that multiple times.

But what clearly hasn't happened is anyone who is a proponent of Corsi, hasn't stepped to the plate and successfully refuted my premise on why Corsi is unreliable to rate individual players.

And the premise you offered earlier in this thread involving goals and assists, makes me wonder if the premise of false data is even clearly understood. Because that is not even remotely the same as how false shot data is compiled in forming Corsi data.
Tomahawk
Location: Driver's Seat: Mitch Marner bandwagon. Grab 'em by the Corsi.
Joined: 02.04.2009

Jul 15 @ 10:46 AM ET
I have stated multiple times that even the developers of Corsi are aware of it's flaws, and how that has to be taken into account when used. But time and again, it's misused to rate individual players.
- MJL


So nobody who talks about Corsi here makes a note of mentioning contextual info like ZS, QoC, tactics, linemates/partners to offset some of the inherent 'flaws'?

Common, that's BS.

Yes, Corsi NEEDS context -- and we tend to give it.

Goals/points NEED context, too. Otherwise, somebody might believe that Brayden Schenn is more valuable to the Flyers than Couturier, because he has more points over the past several seasons.

Even you have to admit, context got a lot easier since the same people who developed Corsi started tracking and publishing usage data.

Secondly, you are also incorrect in stating that I have claimed every advanced stat is false. I've stated repeatedly that I think that Corsi as a team stat is a pretty good stat. Because the issues of false data is removed. Thirdly, I've never stated that the false data renders the stat useless. Only that it is unreliable to rate individual players, but it is again, a good stat, in fact really the only stat and best available to measure possession on a team basis.
- MJL


So you like it... but just make a point to undermine it at every turn? That's odd.

And lastly, I have repeatedly not only posted game examples of how the false data is accumalated, but also have provided articles from reliable sources that support my opinion. And I've done that multiple times.
- MJL


You mean like the article about Fistric you keep quoting from? The one that doesn't make any mention that he only spent a measly 25-games w/ the Oilers that season and tried to compare him to guys who spent a full season there?


But what clearly hasn't happened is anyone who is a proponent of Corsi, hasn't stepped to the plate and successfully refuted my premise on why Corsi is unreliable to rate individual players.
- MJL


There's a mountain of work out there that addresses your concern. I suggest that you do a little bit of reading yourself, instead putting demands on people here to answer all your questions for you.




Again, Corsi needs context. If somebody here just says Player A is better than Player B because he has a higher CF%, I'd be the first one to question that methodology.

You've seen me try to put the Umberger trade in context, and not just slavishly support Hartnell b/c he had great possession numbers.

So why keep making it sound like people who mention stats believe that Corsi is some magic, perfect catch-all stat?
MJL
Philadelphia Flyers
Location: Candyland, PA
Joined: 09.20.2007

Jul 15 @ 11:25 AM ET
So nobody who talks about Corsi here makes a note of mentioning contextual info like ZS, QoC, tactics, linemates/partners to offset some of the inherent 'flaws'?

Common, that's BS.

Yes, Corsi NEEDS context -- and we tend to give it.

Goals/points NEED context, too. Otherwise, somebody might believe that Brayden Schenn is more valuable to the Flyers than Couturier, because he has more points over the past several seasons.

Even you have to admit, context got a lot easier since the same people who developed Corsi started tracking and publishing usage data.


- Tomahawk


No, it's not BS. The entire conversation on Grossmann and his value as a player, clearly points out that it's used in poor context. As does criticism leveled to numerous other players, such as MacDonald. Proof positive.



So you like it... but just make a point to undermine it at every turn? That's odd.


- Tomahawk


Must be a reading comprehension problem . I like Corsi as a team stat. I think it's unreliable as an individual stat for rating players. Because of the false data issue. With the team stat, the false data issue is removed. Not odd at all.


You mean like the article about Fistric you keep quoting from? The one that doesn't make any mention that he only spent a measly 25-games w/ the Oilers that season and tried to compare him to guys who spent a full season there?


- Tomahawk


Your only dealing with one part of the article, and that was only one example given. It was a pretty extensive and long article.




There's a mountain of work out there that addresses your concern. I suggest that you do a little bit of reading yourself, instead putting demands on people here to answer all your questions for you.


- Tomahawk


I've researched Corsi extensively. This is simply just trying to dodge the issue, and turn the responsibility on someone else. I haven't put any demands on anyone. My stance on Corsi, and what the fatal flaws of it are, and why it shouldn't be used to rate individual players, hasn't been refuted, simply because it can't be. It's just a fact of the stat. And all I've gotten are poor comparable such as goals and assists made earlier.




Again, Corsi needs context. If somebody here just says Player A is better than Player B because he has a higher CF%, I'd be the first one to question that methodology.

You've seen me try to put the Umberger trade in context, and not just slavishly support Hartnell b/c he had great possession numbers.

So why keep making it sound like people who mention stats believe that Corsi is some magic, perfect catch-all stat?

- Tomahawk



Because the majority of people who use Corsi think that it is some perfect magic, perfect catch all stat. And there's plenty of eividenc of that on a regular basis. It's simply unreliable to use to rate individual players.
Tomahawk
Location: Driver's Seat: Mitch Marner bandwagon. Grab 'em by the Corsi.
Joined: 02.04.2009

Jul 15 @ 11:46 AM ET
No, it's not BS. The entire conversation on Grossmann and his value as a player, clearly points out that it's used in poor context. As does criticism leveled to numerous other players, such as MacDonald. Proof positive.
- MJL


I distinctly recall people bringing up eyeball observations, entry/exit data (OMG, also flawed!) and a number of other things during those debates.

Must be a reading comprehension problem . I like Corsi as a team stat. I think it's unreliable as an individual stat for rating players. Because of the false data issue. With the team stat, the false data issue is removed. Not odd at all.
- MJL


You act like it's your job to set the record straight every time -- we've read about your issues w/ stats ad nauseum. For all your daily attacks, the number of stats proponents have grown exponentially here over the past few months.

As people start to get a better understanding of what the numbers can (and can't) do, you'll eventually see everybody accept them -- including you eventually, I'm betting.

"All truth passes through three stages. First, it is ridiculed. Second, it is violently opposed. Third, it is accepted as being self-evident." - Arthur Schopenhauer

...that was only one example given. It was a pretty extensive and long article.
- MJL


There was very little take-away value from that piece. It was just some attempted hole-poking by bringing up one single small-sample outlier... it was mostly embarrassing.

I've researched Corsi extensively...
- MJL


I doubt many people here are convinced that you know what you're talking about... thanks to all the newbie mistakes you've made and the chronic lack of understanding that you keep displaying about the field of stats in general, not just to how they relate to hockey.

Because the majority of people who use Corsi think that it is some perfect magic, perfect catch all stat.
- MJL


Names?
MJL
Philadelphia Flyers
Location: Candyland, PA
Joined: 09.20.2007

Jul 15 @ 11:55 AM ET
I distinctly recall people bringing up eyeball observations, entry/exit data (OMG, also flawed!) and a number of other things during those debates.


- Tomahawk


The eye test was given the smallest weight, especially in the Grossmann discussion. Full paragraphs based on stats like Corsi, with one sentence at the end of to paraphrase, "my eye test confirms all of this"



You act like it's your job to set the record straight every time -- we've read about your issues w/ stats ad nauseum. For all your daily attacks, the number of stats proponents have grown exponentially here over the past few months.

As people start to get a better understanding of what the numbers can (and can't) do, you'll eventually see everybody accept them -- including you eventually, I'm betting.

"All truth passes through three stages. First, it is ridiculed. Second, it is violently opposed. Third, it is accepted as being self-evident." - Arthur Schopenhauer


- Tomahawk


There's nothing here that addresses the issue of false data in Corsi for individual players. That simply isn't going away, until they change the way the data is compiled. Which would be very difficult. As I've also said repeatedly, and the article you linked supports, if they could find away to eliminate the false data, or atleast lower it to an acceptable level, it would be a pretty good stat. But at it's current state, not reliable for individual players. It's theory is sound, but the collection of data to form the numbers,for individual players, is flawed.

That little quote is cute, but it assumes that Corsi is "truth" when it's not. It's a flawed result.



There was very little take-away value from that piece. It was just some attempted hole-poking by bringing up one single small-sample outlier... it was mostly embarrassing.


- Tomahawk


The article was quite extensive. It dealt with first bringing up and explaining the basic premise of the article, including giving some sound examples of how false data is compiled. It also looked at the Roth/Irvin system. As well as looking at a case study involving a player to illustrate the flaws. And also offering how the stat cold be made better. And the author also linked numerous other reference articles to support his conclusion. So the only thing embarrasing here is really the complete and gross misrepresentation of the context and content of the article.



I doubt many people here are convinced that you know what you're talking about... thanks to all the newbie mistakes you've made and the chronic lack of understanding that you keep displaying about the field of stats in general, not just to how they relate to hockey.


- Tomahawk


I have no need to lower myself to this level. I'm only interested in discussing the context of the debate and the opinions offered. Not those making the opinions.

I challenge you to refute the premise of flawed data in using Corsi to rate individual players. It's that simple. That's what the discussion is about.



Who?

- Tomahawk


No need to name names. The subject of Corsi and it's use, is the debate.
Tomahawk
Location: Driver's Seat: Mitch Marner bandwagon. Grab 'em by the Corsi.
Joined: 02.04.2009

Jul 15 @ 12:11 PM ET
That little quote is cute, but it assumes that Corsi is "truth" when it's not. It's a flawed result.
- MJL


It's as much truth as any other statistical record... the sooner you learn to accept that the better, because this thing is moving forward with a ton of momentum and it really doesn't care if you're on board or not.

Keep kicking and screaming all you want, eventually nobody's going to give a (frank).
MJL
Philadelphia Flyers
Location: Candyland, PA
Joined: 09.20.2007

Jul 15 @ 12:44 PM ET
It's as much truth as any other statistical record... the sooner you learn to accept that the better, because this thing is moving forward with a ton of momentum and it really doesn't care if you're on board or not.

Keep kicking and screaming all you want, eventually nobody's going to give a (frank).

- Tomahawk



Again, this has zero to do with the debate on Corsi and the effects of false data on the numbers compiled. This is now how many replies on the debate, without once addressing the issue of false data with Corsi.

The Roth/Irvin system of plus/minus moved forward, with a ton of momentum, and really didn't care about who was on board. And it didn't matter who cared either.

But you and I know the flaws involved with it, don't we? So really what does what you posted have anything to do with anything? It doesn't! It's just tap dancing around the issue.

And Corsi is no where near as truthful as any other statistical record. That's obvious.
Tomahawk
Location: Driver's Seat: Mitch Marner bandwagon. Grab 'em by the Corsi.
Joined: 02.04.2009

Jul 15 @ 12:50 PM ET
Again, this has zero to do with the debate on Corsi and the effects of false data on the numbers compiled. This is now how many replies on the debate, without once addressing the issue of false data with Corsi.
- MJL



The issue has been addressed. Not a single stat in hockey truly encapsulates individual achievement/value... not a single one. All inadvertently capture the contribution of teammates, opponents and coaches.

So what makes Corsi different? Not a damned thing.
Tomahawk
Location: Driver's Seat: Mitch Marner bandwagon. Grab 'em by the Corsi.
Joined: 02.04.2009

Jul 15 @ 1:03 PM ET
...plus/minus moved forward, with a ton of momentum, and really didn't care about who was on board. And it didn't matter who cared either.

But you and I know the flaws involved with it, don't we? So really what does what you posted have anything to do with anything? It doesn't! It's just tap dancing around the issue.

- MJL


Yeah, +/- is based on goals, which is the problem. Relatively small sample size, variability of SH%, and variability of SV% render it relatively non-predictive. A guy could be +20 one season and -20 the next. It's way too dependent on everything around him.

Team and individual shot attempt #'s are highly repeatable from season to season, hence they hold much more value and are much more predictive.

For all your research, you think you would have understood the critical difference between +/- and shot metrics.

MJL
Philadelphia Flyers
Location: Candyland, PA
Joined: 09.20.2007

Jul 15 @ 1:10 PM ET
The issue has been addressed. Not a single stat in hockey truly encapsulates individual achievement/value... not a single one. All inadvertently capture the contribution of teammates, opponents and coaches.

So what makes Corsi different? Not a single thing.

- Tomahawk



No that's not addressing it. That's tap dancing around it. Let's go back to a post you made earlier today about player who help move the puck up the ice that contributes to a goal being scored, and receives no statistical credit for it. And that type of thing certainly happens in Hockey. But what doesn't happen there, is for false data to be accumulated in the assist or goal stat column. And it was really a bad comparable to offer. So I guess we have to go back to the basics.

The event measured in the goal stat column is obviously a goal scored by a player. The event measured in Corsi, is a shot attempted for or against. So let's explore the difference here. When a shot attempted for on the ice happens, every player that is on the ice for that team, gets that added to their column. So a player who wasn't even involved in the play, can get credit statistically for something that he had nothing to do with. Same as with a shot attempted against. A player could have played his check and his man, or the puck perfectly. But a teammate screwed up, leading to a shot attempt against. And that goes into every players column for the purpose of comiling Corsi numbers.

Now in order for goals to be a comparable situation, when a goal is scored on the ice for a team, every player on the ice would get a goal scored added to their stat column. Which would also add a large amount of false data to skew the stat. But that doesn't happen. Now while the player that made the nice breakup or outlet pass to start the play, that was more then two passes away from the goal, doesn't get statistical credit for the play. What also doesn't happen is that there is no false data contributed.
Now there is certainly some human element involved there. But the NHL is pretty good ad reviewing game tape to makes sure the correct player gets credit for a goal or an assist. But it's not 100% foolproof. And there are also instances where a freak occurrence happens such as an "own goal" where a player gets credit for a blunder by the opposition. But those two instances pale in comparison to the every game accumalation of false corsi shot data.

So as we can see here, there is a clear difference in our opinions offered. I'm willing to actually debate the subject and make reasonable points, rather then focus on the poster making the opinion.

And I again I offer the direct challenge of refuting my opinion of why Coris is not reliable to rate individual players, due to the issue of false data.
MJL
Philadelphia Flyers
Location: Candyland, PA
Joined: 09.20.2007

Jul 15 @ 1:14 PM ET
Yeah, +/- is based on goals, which is the problem. Relatively small sample size, variability of SH%, and variability of SV% render it relatively non-predictive. A guy could be +20 one season and -20 the next. It's way too dependent on everything around him.

Team and individual shot attempt #'s are highly repeatable from season to season, hence they hold much more value and are much more predictive.

For all your research, you think you would have understood the critical difference between +/- and shot metrics.


- Tomahawk



This ignores how I have repeatedly posted that Corsi solves one problem of small sample size of goal events in a game, which makes it an improvement over standard +/-. I've posted that multiple times over the course of Corsi discussions. So the above is really just a poor assumption not based on the reality of the situation, and not at all an accurate description of what I understand.

And again is just focused on the poster instead of the subject matter, and the issue of false data in Corsi.
Tomahawk
Location: Driver's Seat: Mitch Marner bandwagon. Grab 'em by the Corsi.
Joined: 02.04.2009

Jul 15 @ 1:18 PM ET
No that's not addressing it. That's tap dancing around it. Let's go back to a post you made earlier today about player who help move the puck up the ice that contributes to a goal being scored, and receives no statistical credit for it. And that type of thing certainly happens in Hockey. But what doesn't happen there, is for false data to be accumulated in the assist or goal stat column. And it was really a bad comparable to offer. So I guess we have to go back to the basics.

The event measured in the goal stat column is obviously a goal scored by a player. The event measured in Corsi, is a shot attempted for or against. So let's explore the difference here. When a shot attempted for on the ice happens, every player that is on the ice for that team, gets that added to their column. So a player who wasn't even involved in the play, can get credit statistically for something that he had nothing to do with. Same as with a shot attempted against. A player could have played his check and his man, or the puck perfectly. But a teammate screwed up, leading to a shot attempt against. And that goes into every players column for the purpose of comiling Corsi numbers.

Now in order for goals to be a comparable situation, when a goal is scored on the ice for a team, every player on the ice would get a goal scored added to their stat column. Which would also add a large amount of false data to skew the stat. But that doesn't happen. Now while the player that made the nice breakup or outlet pass to start the play, that was more then two passes away from the goal, doesn't get statistical credit for the play. What also doesn't happen is that there is no false data contributed.
Now there is certainly some human element involved there. But the NHL is pretty good ad reviewing game tape to makes sure the correct player gets credit for a goal or an assist. But it's not 100% foolproof. And there are also instances where a freak occurrence happens such as an "own goal" where a player gets credit for a blunder by the opposition. But those two instances pale in comparison to the every game accumalation of false corsi shot data.

So as we can see here, there is a clear difference in our opinions offered. I'm willing to actually debate the subject and make reasonable points, rather then focus on the poster making the opinion.

And I again I offer the direct challenge of refuting my opinion of why Coris is not reliable to rate individual players, due to the issue of false data.

- MJL



Omitted data is just as 'false' as superfluous data in statistics. Both can corrupt a data set and lead to bad conclusions.

There's nothing you can do about that, except for refine your data-collection methods. Adv stats people are in the process of doing just that. I can't say the same about the NHL scorekeepers.

Tomahawk
Location: Driver's Seat: Mitch Marner bandwagon. Grab 'em by the Corsi.
Joined: 02.04.2009

Jul 15 @ 1:19 PM ET
And again is just focused on the poster instead of the subject matter...

- MJL


You need to come up with a new out for when you get pinned into a corner... that one is getting tired and predictable.
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