I just found it again.
you can click on the rating system link from
http://www.flyordie.com/tanx/help.html
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Rating system
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Ratings are amended each time you kill someone by adding small amount from your previous rating value. On the other hand, a small amount is subtracted if you've been killed. The amount added or subtracted depends on the ratings of the players.
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Rating difference Probability of win
0 0.50
100 0.54
200 0.59
400 0.68
800 0.82
1200 0.91
1800 0.97
2400 0.99
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Overall ratings are decreased each day by an amount depending on the current rating.
Rating Amount subtracted
below 500 1
600 2
800 5
1000 8
1500 18
2000 32
So players with higher rating will see their rating decrease quicker. A 500 rating will reach zero in approximately 1.5 years without playing.
Series of games
Playing a series of games against the same opponent within a given time interval will adjust the calculation as follows:
The expected score is calculated for the series of games from the pre-match rating-difference of the two players, and the ratings are amended based on the expected score and the actual score of the series of games. These are basically the extensions of the above calculation for more games played. However, as more matches will reflect the skill difference more precisely, the amendment is raised based on the number of games played.
Number of games in a series of games Maximum rating change.
1 4
2 10
3 15
4 20
5 24
6 28
7 32
8 35
9 38
10 41
15 50
20 56
infinite 64
Note that if you play a 3rd player in between playing the same opponent, it will still be treated as a series of games.
---------------------------------------------------------Rating categories:
General of the army
General Above 700
Lieutenant General 600 - 699
Major General 550 - 599
Brigadier General 500 - 549
Colonel 450 - 499
Lieutenant Colonel 400 - 449
Major 350 - 399
Captain 300 - 349
First Lieutenant 250 - 299
Second Lieutenant 200 - 249
Staff Sergeant 150 - 199
Sergeant 100 - 149
Corporal 50 - 99
Private 1st class 0 - 49
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Hope this helped you
