View Single Post
Old
04-29-2012, 09:25 AM
  #60
plusandminus
Registered User
 
Join Date: Mar 2011
Posts: 980
vCash: 500
Quote:
Originally Posted by seventieslord View Post
Just to make sure, how sure are you that you executed the estimate formula the same way that the originators did? I know that a factor of 1.2 or 1.3 is applied to first lines at ES, so it wouldn't surprise me if something similar or greater was applied on the PK too. Because it's true, top unit PKers should end up with more GA, typically. the fact that they are facing top PP unity typically outweighs the fact that they are the best PKers, right? I can't imagine they would have done this project without accounting for that, but I could be wrong.
Just to make sure, what formula and project do you refer to?
You mention 1st lines, but is that really so "black and white"? It seems that many players move around a lot between different lines?

When I wrote here yesterday, it was about the simple kind of situational estimations that focused only on situational GF+GA.
Estimated ES icetime = ESGF+ESGA / teamESGF+teamESGA.
Estimated PP icetime = PPGF+PPGA / teamPPGF+teamPPGA.
Estimated SH icetime = SHGF+SHGA / teamSHGF+teamSHGA.
The above results in percentages. So as in the Stevens/Niedermayer case, I focused only on SHGF+SHGA.


Quote:
Originally Posted by seventieslord View Post
What did you classify as an "error"? How far away from the actual result did it have to be to be classified as such?
Let's take a made up example:
TeamNameFactualRankOnTeamRankOnTeamAccordingToEstimation
DETDefenceman111
DETDefenceman223
DETDefenceman332
DETDefenceman444
Two of the defencemen got correct rankings, while two didn't. 50 % correct. Sometimes the ranking was correct, sometimes off by 1 placement, sometimes by more.


Quote:
Originally Posted by seventieslord View Post
I think the unreliability of these numbers gets overstated by the conservative types around here. Everywhere you look, the players with the reputations of being the best players end up with the highest results and the worst end up with the lowest.
I too think that they basically pass the "eye-test" in the way you describe here. But I still think they may be up to 1-4 minutes wrong for the top players. If one player ends up with 28:22 per game, and another 29:20, I think we cannot be sure at all which one of them that actually had more factual icetime.
To keep to the original topic of this thread, that really shouldn't matter much anyway.

My main concern might be to be careful to distinguish between what we do know and what we don't know.
For stats from say 1970-71, we just hame GF, GA, PPGF, PPGA. An estimation is being made to calculate ESGF, ESGA, SHGF and SHGA. After that, those numbers are being used to estimate situational icetime shares within teams. After that, we estimate how much situational icetime each team as a whole might have had during the specific season. Then we combine the first estimation(s) with the last, to get our final result.

Maybe icetime in itself shouldn't be the ideal criteria anyway? Maybe "a minute is a minute" isn't the best way to approach this, as it is so often pointed out that there could be a significant difference between a "hard" minute and an "easy" one?


Quote:
Originally Posted by seventieslord View Post
You probably know your numbers better than I do. As far as the accuracy of the numbers, I am just parroting what I was told, and I do know 96% correllation doesn't necessarily mean "96% correct". I do think the numbers pass the smell test though - what about you?
Well, basically it does. There surely is a strong correlation between minutes played and goals on ice for. The more one plays, the more goals one will be on ice for, even though the pace may be different for different players. I do think it passes the smell test overall, but in cases of a less than 2-3 minutes difference I think one should keep an open mind to that we don't know for sure which player actually played the more minutes. And we certainly don't know everything about the quality of the minutes.

By the way, here is a curiosity that I've been thinking about. Lidstrom has several times led the best team in the league in icetime. Sometimes he has even has had the most ES and PP and SH minutes on the team, despite playing on such a great team. How come? Is it because he has greater endurance(?) than other players in the league? Wouldn't one expect every team to have their 1st defenceman logging huge minutes? An average defenceman playing on a team with poor defencemen should be able to have the same role as Lidstrom has in Detroit and log similar numbers. Yet it's often the best defencemen of the league that ends up with the most minutes. (I haven't studied this yet, it's just a more or less spontanous thought.)


Quote:
Originally Posted by seventieslord View Post
What's more, with no change to the methodology used, it ends up with higher totals of top players in the first 20 years post-expansion compared to what we're used to nowadays, which is exactly how everyone remembers it.
Yes.


Quote:
Originally Posted by seventieslord View Post
I think that no matter what you do, you should keep it scaled relative to league size. So if you choose 30 players in a 6-team league, you need to use 150 in a 30-team league. Not because the talent pool is five times larger, BUT, the amount of players with the opportunity to play x number of minutes and thus score x number of points in a season, does change proportionally with the number of teams.
Sounds logical to me too.

plusandminus is offline   Reply With Quote