## Search found 2456 matches

Fri Jun 18, 2010 2:26 am
Forum: Computer Chess Club: General Topics
Topic: Chess Statistics
Replies: 42
Views: 5420

### Re: Chess Statistics

Just to give a little secret, your precise formula is nothing but: (w+l)!/w!/l!*0.5^w*0.5^l where you take values for which w-l is bigger than the score. For the case when w-l is exactly equal to the score you take 1/2 of the value making the simplest interpolation. So your "precise" formula is exac...
Fri Jun 18, 2010 1:37 am
Forum: Computer Chess Club: General Topics
Topic: Chess Statistics
Replies: 42
Views: 5420

### Re: Chess Statistics

The precise formula for 1/1/0 gives 1 - (Binomial[3, 0] + Binomial[2, 0])/2^3=0.75 LOS Ok enough of that "precise" formula mambo jambo. There cannot be precise formula for trinomial statistics using binomial formulas. The draws have the impact, even though very small, and that obviously makes you b...
Thu Jun 17, 2010 7:51 pm
Forum: Computer Chess Club: General Topics
Topic: Chess Statistics
Replies: 42
Views: 5420

### Re: Chess Statistics

I do not want to enter into intuitive guesses. The draws for LOS do not enter in the precise calculation of LOS given by my earlier PRECISE formula. It cancels. If you go to check it, you will see that a statistical calculation (I have one, but I do not know how to attach it to a message or PM, it ...
Thu Jun 17, 2010 2:32 pm
Forum: Computer Chess Club: General Topics
Topic: Chess Statistics
Replies: 42
Views: 5420

### Re: Chess Statistics

Seems you do not understand the result. I know that it is a trinomial distribution, used to calculate the error intervals, there the number of draws is very important. But for LOS it is not. Can you understand that or your brain is just flat? What Edmund is saying is correct, what you are saying si...
Thu Jun 17, 2010 1:22 pm
Forum: Computer Chess Club: General Topics
Topic: Chess Statistics
Replies: 42
Views: 5420

### Re: Chess Statistics

YOU asked it, now take that: For any match +a =b -c, the formula which gives the exact LOS LOS = 1 - ( binomial( a+c+2,0) + binomial( a+c+2,1) + ... + binomial( a+c+2, c) + binomial(a+c+1,c) ) / 2^(a+c+2) and nothing depends on the number of draws. Seams you don't understand the problem from the st...
Thu Jun 17, 2010 1:19 pm
Forum: Computer Chess Club: General Topics
Topic: Chess Statistics
Replies: 42
Views: 5420

### Re: Chess Statistics

Edmund wrote:in your example loss_ratio = 0
thus having a negative square root
I agree it doesn't work for zero, so you can't use it per se in my example, but works for any positive number .
However, you can use the same "trick" as for elo calculations when there are zero points for one opponent.
Thu Jun 17, 2010 1:10 pm
Forum: Computer Chess Club: General Topics
Topic: Chess Statistics
Replies: 42
Views: 5420

### Re: Chess Statistics

the variance in my calculation = SQRT((1 - Draws/N) * N) So in your example: 1/10000/0: SQRT((1 - 10000/10001) * 10001) vs 1/0/0: SQRT((1 - 0/1) * 1) the difference is very low Ok that explains. Your variance approximation is not accurate enough for these cases. Why not use SQRT((win_ratio*loss_rat...
Thu Jun 17, 2010 1:05 pm
Forum: Computer Chess Club: General Topics
Topic: Chess Statistics
Replies: 42
Views: 5420

### Re: Chess Statistics

Laskos wrote:Likelihood of Success that one engine is better than another. It does not depend on the number of draws. Error intervals yes, depend. If you want a precise formula for LOS, I can give it.
Would you please give it, since just expending the acronym doesn't tell much.
Thu Jun 17, 2010 12:57 pm
Forum: Computer Chess Club: General Topics
Topic: Chess Statistics
Replies: 42
Views: 5420

### Re: Chess Statistics

you will notice that the draw rate is very much considered. It shouldn't be considered for LOS. (your example is wrong, look at the number of losses). Seams you have a different definition of LOS. How are you defining it then? P.S. Table formulas like ones based on just difference in wins/losses ar...
Thu Jun 17, 2010 12:55 pm
Forum: Computer Chess Club: General Topics
Topic: Chess Statistics
Replies: 42
Views: 5420

### Re: Chess Statistics

This los calculation uses an normal distribution to approximate the win distribution. The otherwise needed multinominal distribution would take ages to calculate an exact value for your request with > 10000 games. Of course you use normal distribution approximation. There is nothing wrong in using ...