HFBoards  

Go Back   HFBoards > General Hockey Discussion > By The Numbers
By The Numbers Hockey Analytics... the Final Frontier. Explore strange new worlds, to seek out new algorithms, to boldly go where no one has gone before.

+/- anomalies

Reply
 
Thread Tools Search this Thread
Old
03-05-2012, 02:52 PM
  #51
Iain Fyffe
Hockey fact-checker
 
Iain Fyffe's Avatar
 
Join Date: Feb 2009
Location: Fredericton, NB
Country: Canada
Posts: 1,948
vCash: 500
Quote:
Originally Posted by Ogopogo View Post
Thank you for taking my bait and proving my point.

10 games played is EXACTLY my point. 11 players had better +/- than Orr that year because they played more games on a good team. +/- has so many external factors that are not controlled by the individual that it is a completely worthless number.
That's just ridiculous. If you think the number of games counts as an externality that invalidates the statistic, then the same externality invalidates all recorded statistics.

If that's the point you were trying to make, it is the weakest point I think I've ever seen, and does nothing to support your argument.

Again, you're going to need a better example.

Iain Fyffe is offline   Reply With Quote
Old
03-05-2012, 03:16 PM
  #52
Nalyd Psycho
Registered User
 
Nalyd Psycho's Avatar
 
Join Date: Feb 2002
Location: No Bandwagon
Country: Canada
Posts: 22,188
vCash: 500
Quote:
Originally Posted by seventieslord View Post
I agree, but if corsi is probably adjusted for shot quality we probably have a winner.

(maybe it already is? I haven't researched it hard enough)
If so then absolutely that is a great efficiency stat.

__________________
Every post comes with the Nalyd Psycho Seal of Approval.
Nalyd Psycho is online now   Reply With Quote
Old
03-05-2012, 03:34 PM
  #53
Prophecy35
Registered User
 
Join Date: Dec 2009
Posts: 218
vCash: 500
If you really consider how statistics actually work, especially in hockey, every stat needs some context, even goals. In 84-85 (random 80s season) there were 56 players that scored 30 goals. Flash forward to 03-04 and there were just 20. Take someone like Warren Young who scored 40 goals, and then any one of Iginla/Kovy/Nash at 41. Are they nearly equivalent at face value? Sure, goals are goals after all. Was Young as effective? Well if just reading the stat line was that straightforward, then you would have no reason to notice that he played with Lemieux and never had a season like that before or after.

I don't agree with adjusted stats, and I'm not treating it like the bible, as some do, but context is always necessary when looking at any stat, even something as straightforward as goals.

One player that really is amazing is Herb Cain. What a generational talent. I mean, he won the NHL scoring race in 43-44. Fabulous. That is precisely what you get when not looking at the complete picture.

The reality is, that was during the extremely watered down war years, it was an anomaly season for him to an extreme degree, and he has no real accomplishments of note outside of that season, as far as I can tell.

Simply put, no matter what the stat, it can almost never be taken at face value. I still maintain that +/-, though a troublesome stat, can be useful when used in the right contexts.

Prophecy35 is offline   Reply With Quote
Old
03-05-2012, 03:38 PM
  #54
Ogopogo*
 
Ogopogo*'s Avatar
 
Join Date: Apr 2005
Location: Edmonton
Country: Canada
Posts: 14,216
vCash: 500
Quote:
Originally Posted by Iain Fyffe View Post
That's just ridiculous. If you think the number of games counts as an externality that invalidates the statistic, then the same externality invalidates all recorded statistics.

If that's the point you were trying to make, it is the weakest point I think I've ever seen, and does nothing to support your argument.

Again, you're going to need a better example.
Read post 23

Ogopogo* is offline   Reply With Quote
Old
03-05-2012, 04:28 PM
  #55
Iain Fyffe
Hockey fact-checker
 
Iain Fyffe's Avatar
 
Join Date: Feb 2009
Location: Fredericton, NB
Country: Canada
Posts: 1,948
vCash: 500
Quote:
Originally Posted by Ogopogo View Post
Read post 23
Did that already, though with the personal attacks it contains on anyone who disagrees with you, it's difficult to take it seriously.

Besides that, of course, is the obvious fact that the Orr example was presented by you after the post you refer to here, so surely it was meant to make an additional point of some kind, yes?

Iain Fyffe is offline   Reply With Quote
Old
03-05-2012, 04:31 PM
  #56
Iain Fyffe
Hockey fact-checker
 
Iain Fyffe's Avatar
 
Join Date: Feb 2009
Location: Fredericton, NB
Country: Canada
Posts: 1,948
vCash: 500
Quote:
Originally Posted by Prophecy35 View Post
Simply put, no matter what the stat, it can almost never be taken at face value. I still maintain that +/-, though a troublesome stat, can be useful when used in the right contexts.
This is the essential point. +/- is more troublesome than certain stats, of course (though less than some others), but writing it off as useless is naive.

Iain Fyffe is offline   Reply With Quote
Old
03-05-2012, 04:33 PM
  #57
Johnny Engine
Registered User
 
Join Date: Jul 2009
Posts: 1,012
vCash: 500
Quote:
Originally Posted by tarheelhockey View Post
Here's the problem, though.

...links...

The major outlets including the NHL present raw +/- as THE basic measure of defense. Even if you go a step deeper and look at the NHL's main stat sheets: http://www.nhl.com/ice/playerstats.h...=nav-sts-indiv

it gives you GP-G-A-P-plusminus-PIM as the basic stat line with 7 more columns until you get to TOI... which apparently ranks with shifts/game and faceoff% in their list of priorities. This sends a message to people looking at leaderboards that raw +/- is a meaningful statistic in and of itself. The people running stats for the league should surely be expected to know better, even if the media outlets don't.
Yeah, you're definitely right about the way +/- is promoted. That's stupid.
However, I'm just going to throw it out there that when I look at those main stats sheets, the first things I look at, in order, are either points or goals (because one of them will be highlighted), GP (because it's on the hard left), and then TOI (because it's over on the hard right). I'm not sure if it's laid out that way on purpose, or whether my eyes do that because I've already internalized it as one of the more important stats on the sheet.
Either way, when someone says "advanced stats", they aren't talking about TOI.

Johnny Engine is online now   Reply With Quote
Old
03-05-2012, 04:34 PM
  #58
Ogopogo*
 
Ogopogo*'s Avatar
 
Join Date: Apr 2005
Location: Edmonton
Country: Canada
Posts: 14,216
vCash: 500
Quote:
Originally Posted by Iain Fyffe View Post
Did that already, though with the personal attacks it contains on anyone who disagrees with you, it's difficult to take it seriously.

Besides that, of course, is the obvious fact that the Orr example was presented by you after the post you refer to here, so surely it was meant to make an additional point of some kind, yes?
Read carefully.

My additional point was: A player who gets the most ice time on a team that scores more than it allows will likely be the highest +/- player on the team.

Because +/- is a team stat, getting more playing time on that team will affect your +/- more. So, a player that is completely mediocre could have the highest +/- on a good team simply by being on the ice a lot. Being good may have nothing to do with it.

Charlie Huddy comes to mind immediately.

Ogopogo* is offline   Reply With Quote
Old
03-05-2012, 04:43 PM
  #59
seventieslord
Moderator
 
seventieslord's Avatar
 
Join Date: Mar 2006
Location: Regina, SK
Country: Canada
Posts: 21,505
vCash: 500
Quote:
Originally Posted by Ogopogo View Post
could have the highest +/- on a good team simply by being on the ice a lot. Being good may have nothing to do with it.

Charlie Huddy comes to mind immediately.
Being put out on the ice a lot and being good are closely related.

seventieslord is online now   Reply With Quote
Old
03-05-2012, 04:45 PM
  #60
tarheelhockey
Moderator
 
tarheelhockey's Avatar
 
Join Date: Feb 2010
Location: The Triangle
Country: United States
Posts: 23,470
vCash: 500
Over on the Canes board, I have embarked on a season-long project to review every ES goal scored in our games and assign a plus or minus only to players who had a causative effect. The project is crowdsourced by allowing any forumer to post objections or additions, and contains a Margin of Error option in case of disagreement (of which there is surprisingly little).

See here: http://hfboards.hockeysfuture.com/sh....php?t=1013809

Of course it won't be finished till next month, but I hope it can be used to benchmark the accuracy of standard plus-minus.

One interesting discovery that is already apparent: forwards are near-universally "plus" players and defensemen are near-universally "minus" players. The nature of their positions limits the impact they can have on each end of the ice. So, one apparent weakness of standard +/- is that it distributes pluses (defensemen) and minuses (forwards) in a manner that is completely team-dependent and can't be adjusted.

tarheelhockey is offline   Reply With Quote
Old
03-05-2012, 04:47 PM
  #61
Iain Fyffe
Hockey fact-checker
 
Iain Fyffe's Avatar
 
Join Date: Feb 2009
Location: Fredericton, NB
Country: Canada
Posts: 1,948
vCash: 500
Quote:
Originally Posted by Johnny Engine View Post
Yeah, you're definitely right about the way +/- is promoted. That's stupid.
Absolutely. Plus-minus is not a defensive stat at all. The plusses come from offence, and the minuses from defence, basically. It's equal parts offence and defence.

Quote:
Originally Posted by Ogopogo View Post
Read carefully.

My additional point was: A player who gets the most ice time on a team that scores more than it allows will likely be the highest +/- player on the team.
Think harder. Who gets the most ice time on a team? Wouldn't that generally be its best players?

Coaches do not send players out at random.

Quote:
Originally Posted by Ogopogo View Post
Because +/- is a team stat, getting more playing time on that team will affect your +/- more. So, a player that is completely mediocre could have the highest +/- on a good team simply by being on the ice a lot. Being good may have nothing to do with it.
No kidding, that's why you don't take it at face value. You're still well short of demonstrating that there is zero value in the stat.

Iain Fyffe is offline   Reply With Quote
Old
03-05-2012, 04:48 PM
  #62
tarheelhockey
Moderator
 
tarheelhockey's Avatar
 
Join Date: Feb 2010
Location: The Triangle
Country: United States
Posts: 23,470
vCash: 500
Oh -- and another thing about tha project which I think is an improvement. It excludes ENG and SHG.

tarheelhockey is offline   Reply With Quote
Old
03-05-2012, 05:27 PM
  #63
plusandminus
Registered User
 
Join Date: Mar 2011
Posts: 776
vCash: 500
Quote:
Originally Posted by tarheelhockey View Post
Over on the Canes board, I have embarked on a season-long project to review every ES goal scored in our games and assign a plus or minus only to players who had a causative effect. The project is crowdsourced by allowing any forumer to post objections or additions, and contains a Margin of Error option in case of disagreement (of which there is surprisingly little).

See here: http://hfboards.hockeysfuture.com/sh....php?t=1013809

Of course it won't be finished till next month, but I hope it can be used to benchmark the accuracy of standard plus-minus.

One interesting discovery that is already apparent: forwards are near-universally "plus" players and defensemen are near-universally "minus" players. The nature of their positions limits the impact they can have on each end of the ice. So, one apparent weakness of standard +/- is that it distributes pluses (defensemen) and minuses (forwards) in a manner that is completely team-dependent and can't be adjusted.
Interesting. Do you prefer feedback here in this thread or in the thread in the Carolina section?

I have only glanced, but can imagine it being controversial to align + and - arbitrarily. (I know you are serious and provide videos and gives explanations, which is good.) For example, not being involved in the play can be a minus when allowing a goal. Sometimes a goal against may also be the goalie's fault. But as I say, I have only glanced, and maybe you are considering that.
At first look, it seems that you could do well to combine this with icetimes. That is because forwards generally gets +, and defencemen generally -.

Something I miss, is two columns showing the "factual" + and - (for even strength only, excluding empty net goals, which I understood was what you're looking at). Then one can compare how "favoured" or "unfavoured" different players are.

plusandminus is offline   Reply With Quote
Old
03-05-2012, 05:34 PM
  #64
Ogopogo*
 
Ogopogo*'s Avatar
 
Join Date: Apr 2005
Location: Edmonton
Country: Canada
Posts: 14,216
vCash: 500
Quote:
Originally Posted by Iain Fyffe View Post
Absolutely. Plus-minus is not a defensive stat at all. The plusses come from offence, and the minuses from defence, basically. It's equal parts offence and defence.


Think harder. Who gets the most ice time on a team? Wouldn't that generally be its best players?

Coaches do not send players out at random.


No kidding, that's why you don't take it at face value. You're still well short of demonstrating that there is zero value in the stat.
If you need to "find the context" for every player to figure out what their +/- really means, then the stat is useless. You could just "find the context" and not even care about their +/-.

If the +/- cannot give you a realiable indication of anything for an individual, it is garbage.

It is like trying to run a science experiment without controlling the variables. Your conclusions mean nothing because it could be one of a dozen things giving you the result.

Ogopogo* is offline   Reply With Quote
Old
03-05-2012, 05:35 PM
  #65
Ogopogo*
 
Ogopogo*'s Avatar
 
Join Date: Apr 2005
Location: Edmonton
Country: Canada
Posts: 14,216
vCash: 500
Quote:
Originally Posted by seventieslord View Post
Being put out on the ice a lot and being good are closely related.
True but not my point.

Ogopogo* is offline   Reply With Quote
Old
03-05-2012, 05:42 PM
  #66
Taco MacArthur
Team Leader
 
Taco MacArthur's Avatar
 
Join Date: Sep 2005
Posts: 18,839
vCash: 693
Quote:
Originally Posted by Ogopogo View Post
If the +/- cannot give you a realiable indication of anything for an individual, it is garbage.
Plus-minus gives you a very accurate indication of the number of (non-power play) goals that a player was on the ice for, compared with the number of (non-power play) goals that a player was on the ice against.

In fact, it's 100% accurate. Very reliable.

I'm not sure what sort of magic you're hoping for, but your threshold of "any stat that isn't 100% perfect is completely worthless" must make for a nice world view.

Taco MacArthur is offline   Reply With Quote
Old
03-05-2012, 05:47 PM
  #67
Johnny Engine
Registered User
 
Join Date: Jul 2009
Posts: 1,012
vCash: 500
Quote:
Originally Posted by Ogopogo View Post
If you need to "find the context" for every player to figure out what their +/- really means, then the stat is useless. You could just "find the context" and not even care about their +/-.
So you're saying that if two guys play the #1 defenseman role on teams that respectively, lead their divisions, and they both put up 40 points and go out against top lines, one of those guys having a far superior goal differential when he's on the ice doesn't add anything to the comparison?

(by the way, my example doesn't even illustrate the nonsense you just came up with. Context, by defintion, doesn't exist if it isn't context for something.)

Johnny Engine is online now   Reply With Quote
Old
03-05-2012, 05:57 PM
  #68
seventieslord
Moderator
 
seventieslord's Avatar
 
Join Date: Mar 2006
Location: Regina, SK
Country: Canada
Posts: 21,505
vCash: 500
Quote:
Originally Posted by Taco MacArthur View Post
Plus-minus gives you a very accurate indication of the number of (non-power play) goals that a player was on the ice for, compared with the number of (non-power play) goals that a player was on the ice against.

In fact, it's 100% accurate. Very reliable.

I'm not sure what sort of magic you're hoping for, but your threshold of "any stat that isn't 100% perfect is completely worthless" must make for a nice world view.
And isn’t this the guy that has the best players of all-time all nicely lined up in a list based entirely on a points system including an offensive dominance metric that is in complete slavery to top-10s in scoring?

seventieslord is online now   Reply With Quote
Old
03-05-2012, 06:01 PM
  #69
Ogopogo*
 
Ogopogo*'s Avatar
 
Join Date: Apr 2005
Location: Edmonton
Country: Canada
Posts: 14,216
vCash: 500
Quote:
Originally Posted by Taco MacArthur View Post
Plus-minus gives you a very accurate indication of the number of (non-power play) goals that a player was on the ice for, compared with the number of (non-power play) goals that a player was on the ice against.

In fact, it's 100% accurate. Very reliable.

I'm not sure what sort of magic you're hoping for, but your threshold of "any stat that isn't 100% perfect is completely worthless" must make for a nice world view.
It would be so much more effective to abolish +/- in its current form and simply have a guy watching the game and crediting players with a + when they do something on the ice that is clearly a significant positive contribution and giving them a - when they do something that is clearly a negative contribution. Actually watch them play and give individual marks for individual accomplishment or mistakes.

Scrap this garbage of painting everyone with the same brush. Some players make a positive difference and some make a negative difference - giving every single player on the ice credit or blame is the wrong way to do it.


P.S. It is very reliable to tell you what?

Ogopogo* is offline   Reply With Quote
Old
03-05-2012, 06:03 PM
  #70
Ogopogo*
 
Ogopogo*'s Avatar
 
Join Date: Apr 2005
Location: Edmonton
Country: Canada
Posts: 14,216
vCash: 500
Quote:
Originally Posted by seventieslord View Post
And isn’t this the guy that has the best players of all-time all nicely lined up in a list based entirely on a points system including an offensive dominance metric that is in complete slavery to top-10s in scoring?
Please do not post false/inaccurate things about me or things I have done. It is perhaps the very worst form of trolling.

Ogopogo* is offline   Reply With Quote
Old
03-05-2012, 06:03 PM
  #71
Taco MacArthur
Team Leader
 
Taco MacArthur's Avatar
 
Join Date: Sep 2005
Posts: 18,839
vCash: 693
Quote:
Originally Posted by Ogopogo View Post
It would be so much more effective to abolish +/- in its current form and simply have a guy watching the game and crediting players with a + when they do something on the ice that is clearly a significant positive contribution and giving them a - when they do something that is clearly a negative contribution. Actually watch them play and give individual marks for individual accomplishment or mistakes.

Scrap this garbage of painting everyone with the same brush. Some players make a positive difference and some make a negative difference - giving every single player on the ice credit or blame is the wrong way to do it.
Ah, abolish! Let's have less information! I can't interpret a statistic properly, so no one should have access to it!

Are you intending to have the same person watch all games, or different people? Because the first is untenable, and the second introduces all sorts of biases.

Taco MacArthur is offline   Reply With Quote
Old
03-05-2012, 06:05 PM
  #72
Ogopogo*
 
Ogopogo*'s Avatar
 
Join Date: Apr 2005
Location: Edmonton
Country: Canada
Posts: 14,216
vCash: 500
Quote:
Originally Posted by Taco MacArthur View Post
Ah, abolish! Let's have less information! I can't interpret a statistic properly, so no one should have access to it!

Are you intending to have the same person watch all games, or different people? Because the first is untenable, and the second introduces all sorts of biases.
You mean like referees? How does the league survive with those guys if it couldn't possibly have a guy scoring "real" +/-?

Ogopogo* is offline   Reply With Quote
Old
03-05-2012, 06:05 PM
  #73
Taco MacArthur
Team Leader
 
Taco MacArthur's Avatar
 
Join Date: Sep 2005
Posts: 18,839
vCash: 693
Quote:
Originally Posted by Ogopogo View Post
P.S. It is very reliable to tell you what?
The number of (non-power play) goals that a player was on the ice for, compared with the number of (non-power play) goals that a player was on the ice against.

Like I mentioned in the post you quoted. Are you acting dense intentionally? It is perhaps the very worst form of trolling.

Taco MacArthur is offline   Reply With Quote
Old
03-05-2012, 06:06 PM
  #74
Taco MacArthur
Team Leader
 
Taco MacArthur's Avatar
 
Join Date: Sep 2005
Posts: 18,839
vCash: 693
Quote:
Originally Posted by Ogopogo View Post
You mean like referees? How does the league survive with those guys if it couldn't possibly have a guy scoring "real" +/-?
So you're okay with biases now, just not the biases that are inherent in plus-minus?

Taco MacArthur is offline   Reply With Quote
Old
03-05-2012, 06:07 PM
  #75
Ogopogo*
 
Ogopogo*'s Avatar
 
Join Date: Apr 2005
Location: Edmonton
Country: Canada
Posts: 14,216
vCash: 500
Quote:
Originally Posted by Taco MacArthur View Post
The number of (non-power play) goals that a player was on the ice for, compared with the number of (non-power play) goals that a player was on the ice against.

Like I mentioned in the post you quoted. Are you acting dense intentionally? It is perhaps the very worst form of trolling.
Is this for real?

You are saying the current +/- is a reliable measure of a player's effectiveness on the ice - knowing full well a player is given a plus or a minus whether he was involved in the play or not?

Then you speak about dense?

Ogopogo* is offline   Reply With Quote
Reply

Forum Jump


Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -5. The time now is 10:41 PM.

monitoring_string = "e4251c93e2ba248d29da988d93bf5144"
Contact Us - HFBoards - Archive - Privacy Statement - Terms of Use - Advertise - Top - AdChoices

vBulletin Copyright ©2000 - 2013, Jelsoft Enterprises Ltd.
HFBoards.com is a property of CraveOnline Media, LLC, an Evolve Media, LLC company. ©2013 All Rights Reserved.