Wednesday, February 10, 2010

Of Points and Ranking

We have recently had a few comments and questions about the points and ranking system used in the Cribbage Pro game. These comments and questions have been very insightful and helpful in understanding a different perspective, and in response to some of this we are making a few changes to the system.

So, effective immediately, the following changes are now live in the "Top 50" tracking system:

  • Players with unfinished games over 50% of finished games will not qualify for the "Top 50" - they will simply not show up in the top 50 at all until they have played enough games through to bring the percentage back above the line.
  • Players at level 6 or above (points >= 2500) will not be awarded points for a win against a Novice computer player (and no loss of points for a loss) going forward. Players who have already accrued points, will retain their points.
  • Players at level 8 or above (points >= 2750) will not be awarded points for a win against an Intermediate or Novice computer player (and no loss of points for a loss). Players who have already accrued points, will retain their points.
  • The minimum award for a win against the advanced computer will be increased from 2 to 4 points, the intermediate win will stay at 2 but the novice will be decreased to 1.
We believe that these changes will close some of the "loop holes" players have found in the system and will make the ranking in the single-player game more "fair".

Please keep your comments and questions coming in, and let us know what you think.

Since I am writing a post on points and ranking, I should also spend a minute explaining the system being used. Again, if you have sent us an email with this question, the below is going to look familiar.

The first thing to mention here is that it is not a "Ladder" system or a simple points system, it is actually a ranking system which can be foreign to some, so I'll explain what that means. In the next update, we will include more details about the points system we use in the help file to make it more clear what is going on. It is definitely a miss on our part to not have that already included there.

In regards to the points specifically, it is a bit of a technical explanation, so I'll try and explain as best I can. The system is designed for ranking each player as accurately as possible, not a points system as stated earlier, and so as such we give virtual "points" or rankings to the computer players you are playing against (the advanced player is ranked as a "2500" point player). So the points then really is your "Rank" against all others, and just as others win and lose, their points will follow the same algorithm. Those computer players only have so many points themselves to "give away", and as your level goes beyond their level, you get fewer and fewer points up to the minimum amount of 2 points for a win (now adjusted as noted above). Similarly, if you lose then the system works in reverse and so the penalties are larger as your points are larger then theirs (up to the maximum of 41). The system we are using is very close to this one:

It is intended for player to player ranking more then computer ranking, which is why it seems odd right now. When we add the multi-player functions, it will make a lot more sense. However, we may change/tweak the algorithm as well as we are still in beta with it, and it can be concerning to be ranked high and lose so many points so quickly when you lose a game. We will likely keep this one for multi-player either way, as we believe it proves out to be the fairest we have found.

The three point levels the computer players are:

Advanced: 2500
Intermediate: 2000
Novice: 1500

You can use the formula given and these point levels of the computer players to calculate a potential win/loss point award as well. No extra points are given today for a skunk or double skunk beyond what you get by winning by so many points, and we currently do not have plans to change that.

-- Josh