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I reached the lofty heights of 1400 a few short games ago but now back to where I belong. The amount of rating points +/- vary considerably. Will someone explain how this works please?

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Players are rated using the following formula:

New Rating = Old Rating + K * (Score - Win Expectancy)

K is a constant (32 for 0-2099, 24 for 2100-2399, 16 for 2400 and above)

Score is 1 for a win, 0.5 for a draw and 0 for a loss.

The Win Expectancy is calculated using the following formula :

Win Expectancy = 1 / (10^((OpponentRating-YourRating)/400)+1)

The Win Expectancy is used in the rating calculation but is interesting on its own. For example, the calculation below is for a rating difference of 200. This shows that if you have a rating 200 points higher than another player, you can expect to beat them, on average, three times for each four games played.

Win Expectancy = 1 / (10^(-200/400)+1) = 0.76

Note: ^ = "to the power of", e.g. 2^3=8.

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Ah the FAQs. Silly me. Thanks and sorry!

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Originally posted by Dudley
I reached the lofty heights of 1400 a few short games ago but now back to where I belong. The amount of rating points +/- vary considerably. Will someone explain how this works please?
You probably play games that you are winning quicker than the ones you are losing. Its fairly normal for this to happen, as if you are winning, then your plans are probably working, whereas if you feel you are losing, then you'll have to think longer.

D

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Originally posted by Ragnorak
You probably play games that you are winning quicker than the ones you are losing. Its fairly normal for this to happen, as if you are winning, then your plans are probably working, whereas if you feel you are losing, then you'll have to think longer.

D
i find that it's the 50/50 games that take longer...

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