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MNHockey Frequently Asked Questions (FAQ)
  1. How does MNHockey compute its ratings?
  2. Are some teams or leagues given preferential treatment?
  3. How accurate can this be?
  4. We beat Team X twice, how can they still be ranked ahead of us?
  5. We won both our games this past weekend and our rating went down, how is this?
  6. What does a team's overall rating number mean?
  7. What does each of the columns on the ratings page mean?
  8. Why are some game scores missing and team records inaccurate?
  9. A game score is incorrect, how do I get it corrected?
  10. There are missing or duplicate game scores, how do I correct them?
  11. How can my league help?
  12. How can my team help?
  13. How can I help?
  14. How is it that MNHockey is free?

Last updated on 17 Nov 2007.





1. How does MNHockey compute its ratings?
MNHockey's ratings are computed mathematically, with no subjective weighting or human determined values. MNHockey rates teams based upon how well they play against other teams and how good those teams are. These two factors are "AGD" or "average goal differential" and "SCHED" or "strength of schedule". AGD is currently calculated by accumulating the goal differential of each game, to a maximum of 8, and divides it by the number of games played. Using a max game goal differential of 8 does "penalize" teams that blow out opponents, but this is common in rating systems and discourages running up scores. The strength of schedule is computed by averaging the rating of each game opponent. AGD and SCHED are added together to compute a team's rating.


2. Are some teams or leagues given preferential treatment?
There is no preferential treatment for teams from certain leagues. All teams are assumed to be equal and having a rating of zero before the system mathematically calculates your SCHED and AGD based entirely upon game performance. A team's SCHED is not only determined by the teams it plays, but by the teams its opponents play and its opponents' opponents play, etc. This is why a struggling AAA team will likely be ranked above average AA teams.


3. How accurate can this be?
If a group of teams (i.e. a league) doesn't play others outside its group, their placement relative to all other teams cannot be accurately be determined, but relative to one another it is accurate. Groups of teams with limited outside play can be inaccurately skewed by the scores of only a few games, which might not be representative of the group's overall ability. Accuracy significantly increases with more games and more interplay and it makes sense for there to be a minimum number of games before teams are ranked.

Assuming teams have all played enough games against both league and non-league teams, inaccuracies may still exist. Some teams play differently (a lot differently) depending upon which goalie is in net for a specific game. In this case, the ratings average out the play and may not completely reflect either scenario. Missing players, home vs. away, double rostered players are a few other scenarios that could influence the accuracy of the ratings. It's not an exact science. The ratings should be used to determine what teams might be good non-league opponents and which bracket of a tournament may be more appropriate, they are not meant to be the AP Poll for youth hockey.

There are a couple weaknesses to the current system. The first deficiency is with teams that emphasize development in some games. They are "penalized". That same team may then focus on winning big tournaments and succeed, but may never achieve the rating that they "deserve". Secondly, teams that "come on" in the second half of the season are "penalized" by early poor performances. All games throughout the season count equally and that may not reflect a teams performance near the end of the season.


4. We beat Team X twice, how can they still be ranked ahead of us?
Yes, it seems wrong, but a team that you have a winning record against can be ranked ahead of you. It's all in mathematics. It depends on who else your team has played and how well you did as well as who the other team has played and how well they did. In a season of games, there will be some anomalies.


5. We won both our games this past weekend and our rating went down, how is this?
Your rating can go down even though your team wins. This can happen for a couple different reasons. First, if your team is rated 3.0 points (1 point = 1 goal) better than your opponent and you win two close games by 1 goal each, your average goal differential (AGD) is +1.0 against a team that it was expected to be +3.0. This would likely have a negative impact on your rating. Another scenario has you doing as expected against your opponent, but a large percentage of the teams you played earlier in the season doing unexpectedly bad. This lowers your strength of schedule and would lower your team's rating. It is almost impossible to guess how much and in what direction your rating will move each week because of the complexity of the math.

Two additional notes. During the entire season, new team continue to be added to the system. Teams rated in the middle of the pack in October may fall 100 spots by the end of the season while improving, simply because the number of teams added to MNHockey increases over time. It might be best to compare your team to others in your league or geographic area and see if your rating improves relative to theirs. Also, MNHockey now has available a page that explains the mathematics behind the rating. From either the scores page for a particular team or from the team information page, you can find a link to the math page by clicking on the graphic.


6. What does a team's overall rating number mean?
Everything is relative. The number specifically means nothing, but might be used to understand the relative competitiveness of two different teams. A 1.0 point differential equates to a theoretical goal 1.0 goal advantage by the team with the higher point value. Squirts, Peewees and Bantams are all calculated separately. While a Peewee Minor AAA team can get a pretty good sense on how good they would fair against a Peewee Major AA team because all Peewee ratings are calculated relative to one another, one cannot compare a Squirt Major AAA team to a Peewee Minor AA team in the same fashion. MNHockey has some limitations and figuring the relative difference between stronger squirt teams and weaker peewee teams is one of them.


7. What does each of the columns on the ratings page mean?
"Record" is represented by wins-loses-ties. As described above, the "Rating" is simply the sum of the "AGD" and "SCHED". "AGD" is average goal differential. This can be a positive or negative number that equals goals for (GF) minus goals against (GA) divided by games played (GP). One caveat, the system currently has a maximum goal differential of eight for any single game played. This means that if a team plays a number of games decided by more than eight goals, it's not quite as simple as GF-GA/GP. "SCHED" is the average strength of schedule of all opponents. Fundamentally you can add the "RATING" for all opponents and divide by GP. "Details" will give you more information about the team while "Scores" is a link to a team's complete set of season game scores as recorded in MNHockey.

A couple hints to give you the full power of MNHockey. Any teams with known team websites will be represented by underline/hotlinked team names. Clicking on the team name will open an additional window to this team's web site. When viewing scores, each opponent's schedule is just a click away. For example, if you are viewing the game scores of Team X and they played Team Y, you can view Team Y's game scores by simply clicking on Team Y's name.


8. Why are some game scores missing and team records inaccurate?
Missing scores are typically not in the system for one of a couple different reasons. First, games scores found on league and team web sites are the primary source of information and if the game score isn't located on a web site where someone might find it, it won't get entered into the system. Second, game scores against ambiguous teams (i.e. "Rochester" or "Raiders") don't identify the exact opponent and will not get recorded unless the exact team can be identified. Spell out team names more clearly so there is no question in the mind of our volunteers. Lastly, some scores aren't entered or entered in a timely fashion because there is no volunteer covering their league/division. Please consider volunteering. To find out more, go to the Report Scores.


9. A game score is incorrect, how do I get it corrected?
Sometimes mistakes happen. It may be on our side, or it might have come from a team or league web site. Too many humans involved... If reasonable, work to get the score corrected on its posted site first. Then, please send any corrections to errors@mnhockeyrankings.com. Quoting an online third-party source that can verify the correct score makes things easier.


10. There are missing or duplicate game scores, how do I correct them?
Again, mistakes are inevitable. If duplicate scores have been posted, feel free to immediately contact us at errors@mnhockeyrankings.com to get things corrected. We try to catch these ourselves, but we appreciate your help. If they are missing game scores, give us a couple weeks and make sure they are posted on the web first. If they are on the web and we aren't updating the web site, please send the web site listing the games scores to scores@mnhockeyrankings.com.


11. How can my league help?
Accurately post all league scores! The number one thing a league can do is post, on the internet in a timely fashion, all league game scores. Encouraging associations/teams to create team web sites and make non-league game scores available to the public would also help.


12. How can my team help?
Post game results to your associations website or create a team web site and list all game scores in an area where our volunteers can easily find it. Also, please clearly identify your opponents. Ambiguity means we cannot post the results, even if you have them on your web site.


13. How can I help?
Volunteer. Keep us honest. Report tournament results (frequently, it's hard to find complete, accurate and unambigious tournament results). Encourage others to do the same. Please visit the Report Scores page where additional information on volunteering with MNHockey can be found.


14. How is it that MNHockey is free?
MNHockey is free just as Google is free. Advertising will eventually cover the cost of running the website. MNHockey's mission is to provide you the best, most complete and accurate information about Minnesota youth hockey.


 
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