Author: Uri Blass
Date: 02:23:19 11/17/01
Go up one level in this thread
On November 17, 2001 at 03:23:23, Ed Schröder wrote:
>On November 17, 2001 at 01:34:28, Uri Blass wrote:
>
>>On November 17, 2001 at 00:25:14, Ed Schröder wrote:
>>
>>>On November 16, 2001 at 19:12:59, Christophe Theron wrote:
>>>
>>>>On November 16, 2001 at 16:20:45, Hansjoerg wrote:
>>>>
>>>>>Some time ago I posted the (surprising) result from an engine tournament between
>>>>>Fritz 7 and Junior 7 (14.5-4.5).
>>>>>Now I finished 100 games and the result is F7 (49.5) - J7 (50.5)!
>>>>
>>>>
>>>>
>>>>Welcome to the world of statistics!
>>>>
>>>>
>>>>
>>>> Christophe
>>>
>>>
>>>Yep, ask any casino director where his profit comes from :)
>>>
>>>I once have written a 10-line C program, it randomly generates a score
>>>(1-0, 1/2-1/2, 0-1) and then starts counting. Results vary tremendously.
>><snipped>
>>>100 games: 70-30
>>
>>I understand your idea but
>>70-30 between equal programs does not make sense.
>
>
>But Uri, you can program yourself, just try it. It is pure statistics.
I know statistics and I understand numebrs
Even if I assume 50% for a win and 50% for a loss the probability for 70-30
is only (1/2)^100*100!/(70!*30!)=
(1/2)^100*(100*99*98*97*96*95*94*93*92*91*90*89*88*87*86*85*84*83*82*81*80*
79*78*77*76*75*74*73*72*71)/30!
I wrote simple program to calculate it
void main(void)
{
double result;
int i;
result=1;
for (i=71;i<=100;i++)
{
result=result*i;
result=result/2;
result=result/(101-i);
}
for(i=1;i<=70;i++)
result=result/2;
printf("%f ",result);
}
I get the result 0.000023 that means 0.0023%
it is clear that the probability for 71-29 is less than 1/2 of the probability
for 70-30 and the probability for 72-28 is less than 1/2 of the probability of
72-28... so the sum of the probabilities for bigger results than 70-30 is even
smaller so the probability to get strange result of 70-30 is clearly less than
0.01%
>
>And if you are not convinced, run 1000 blitz games, divide them in parts
>of 100, and you will see at least one 70-30 score.
I will not see at least one 70-30 result if the programs are equal.
I may see many 7-3 results but not 70-30 results.
Uri
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