Forums

How are draws calculated in the ELO system

Sort:
aman_makhija

I learnt how the rating changes for wins are calculated

http://www.chess.com/forum/view/general/win-percentages-for-specific-rating-differences

But how does Elo's system calculate the rating changes for draws?

For instance if a 2000 draws a 2100, how many points does he gain with a k-factor of 20?

0110001101101000
aman_makhija wrote:

I learnt how the rating changes for wins are calculated

http://www.chess.com/forum/view/general/win-percentages-for-specific-rating-differences

But how does Elo's system calculate the rating changes for draws?

For instance if a 2000 draws a 2100, how many points does he gain with a k-factor of 20?

From the link:

"K factor x [actual score - expected score]"

-----------

The "actual score" of a draw is 1/2
So a draw against someone rated 100 points higher would be

20 x [0.5 - 0.35] = 3

A draw against someone rated 100 points lower would be

20 x [0.5 - 0.65] =  -3

aman_makhija

Thanks alot, 0110001101101000.

0110001101101000

Smile