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01-21-2013, 12:48 AM
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tarheelhockey
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Join Date: Feb 2010
Location: The Triangle
Country: United States
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2012-13 Qualitative +/- Ratings

Find last year's results here.

The concept

The basic idea of Subjective +/- is very simple: we assign +/- to players based on their actions, rather than their circumstances.

The single fundamental problem with standard +/- is that it is linked to events that have no direct relation to the scoring of goals -- a player gets a + or - regardless of where he was on the ice, or what he was doing. This creates all kinds of problems for the stat, but the bottom line is that it doesn't actually tell you anything about how well or poorly a player has performed. It simply tells you that certain events happened and he was on the ice at the time. This project is an attempt to generate data that actually measures performance in a rationally subjective manner.


The rules

1) Assignment of pluses and minuses is based upon our collective evaluation. We must identify a direct link between a player's actions and the scoring of a goal in order for a point to be assigned.

2) A "plus" is assigned when a player actually contributes to a goal by his actions (or, rarely, by his non-actions). This could be as subtle as a screen or pick away from the puck, but it must have a tangible impact upon the sequence of events that lead directly to the goal.

3) A "minus" is assigned when a player actually contributes to a goal-against by his actions (or, often, by his non-actions). A "minus" is not necessarily related to defensive play; offensive errors which lead directly to a goal against, such as own-goals and turnovers in front of the net, may count as minuses.

4) Only goals scored at even strength will be counted. Unlike standard +/-, SH goals are ignored.

5) Goals scored in the immediate sequence of events following the end of a power play will not be counted, even if they are technically ES goals. The idea is that a team is still essentially shorthanded for a few seconds after a penalty ends.

6) Empty net goals will not be counted.

7) Goals that are judged to be the fault of the goaltender will not be counted. The idea is to hold players responsible for things that are reasonably under their control.


Procedure

I will review each game and post an initial summary of points awarded. This is intended to be a draft, not a final judgment. To the best of my ability, a video showing full replays of each goal will also be posted.

All forumers are welcome and encouraged to review the video and note any potential errors or omissions. This crowd-sourcing of our data ensures that it is valid and useful. Please speak up if you see something that needs to be changed!

If there is a substantial amount of disagreement over a point, it will go in the Margin of Error (MoE) column. This provides some transparency as to the accuracy of the final numbers.



I hope this will be a fun way to learn a little more about our players and the game, and perhaps generate some useable data that will benefit the hockey community in some small way. This being the second season, I'm excited to see how the numbers begin to create a more detailed and informative picture.

To everyone who takes the time to contribute, Thank You!


Last edited by tarheelhockey: 10-11-2014 at 10:17 PM.
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