Good evening,

j00j4nt200 wrote:1.

I tried to simulate formula for curiosity purpose.

Let say I have 2172ratio, and my opponent have 2013 - I win and should have 2179, but in excel i can't get it right:

=2172+24*(1-(1/(1+(10*((2013-2172)/400)))))

Can you help me find where is my mistake?

First it is not like that, let's do this, with your rating, New rating as X ->

X = old rating (2172) + Kfactor(24)*(result(1) - [1/{ 1+10^((2013-2172)/400)}]) --> let's put this easier. First we will start from the right. 2013-2172 = -159 -> -159/400 = -0,3975 --> 10^(-0,3975) = 0,4004054683305463421664975725889 -> 1+0,4004054683305463421664975725889 = 1,4004054683305463421664975725889. Now we divide 1 with 1,4004054683305463421664975725889. -> 0,71407890258535025281131344970418,

next step: x = 2172 + 24 * ( 1-0,71407890258535025281131344970418) -> 1 - 0,71407890258535025281131344970418 = 0,28592109741464974718868655029582 - > next step is multipliying with the k factor.

24 * 0,28592109741464974718868655029582 = 6,8621063379515939325284772070996 ~ nearly 7,

now we solve the new rating.

New rating (x) = 2172 + 6,8621063379515939325284772070996 = 2178,8621063379515939325284772071 since there is no coma, your new rating is 2178+1 = 2179. This means:

New rating (X) = 2179 !!

I hope that helps a bit.

j00j4nt200 wrote:2.

Can you tell me (for curiosity purpose again) what is average user ratio last year, and this year?

And what is average user ratio (for user that played more than 1k games) last year and this year?

I have no idea what the average rating is, but it used to be around 1635 or so when I joined chesscube some 1 year and a half ago. I suppose it is much alike now. maybe a bit higher up to 1800 although I am not too sure.

Regards Xabier.