Author: Dann Corbit
Date: 13:34:58 07/07/05
Go up one level in this thread
On July 07, 2005 at 15:43:03, Dann Corbit wrote:
>On July 07, 2005 at 15:01:26, Dann Corbit wrote:
>
>>On July 07, 2005 at 14:51:56, Gian-Carlo Pascutto wrote:
>>
>>>On July 07, 2005 at 14:37:19, Dann Corbit wrote:
>>>
>>>>On July 07, 2005 at 14:14:36, Gian-Carlo Pascutto wrote:
>>>>
>>>>>On July 07, 2005 at 13:56:04, Dann Corbit wrote:
>>>>>
>>>>>>On July 07, 2005 at 05:05:50, Gian-Carlo Pascutto wrote:
>>>>>>
>>>>>>>On July 05, 2005 at 14:37:46, Dann Corbit wrote:
>>>>>>>
>>>>>>>>The logfile does not consider the depth on-chip at the leaves. About 6 plies
>>>>>>>>more. So consider it really to be 16-18 plies.
>>>>>>>
>>>>>>>This is quite simply completely wrong, and contradicts what Hsu and Campbell
>>>>>>>published.
>>>>>>>
>>>>>>>http://sjeng.org/ftp/deepblue.pdf
>>>>>>
>>>>>>I read the paper. I was referring to this:
>>>>>>"This typically results in 4- or 5-ply searches plus quiescence in middlegame
>>>>>>positions and somewhat deeper searches in endgames."
>>>>>>
>>>>>>I did not see the contradiction. Can you please point it out ot me?
>>>>>
>>>>>The first number in the logs is the combined depth (excluding quiescence, but
>>>>>nobody counts that). The nominal depth was around 12 ply for the combined
>>>>>search, not 16-18.
>>>>
>>>>Then it represents the estimated maximum combined depth (last column of table
>>>>2)?
>>>
>>>No, that's another matter. Maximum depth is rather meaningless.
>>>
>>>Look at Page 5, 1)b) for the statement that the nominal depth is 12 ply on
>>>average. It's been a while since I read it but basically something like 12 (5)
>>>meant 12 - 5 = 7 ply software, 5 ply hardware, and then extensions and quiescene
>>>search.
>>
>>It makes me wonder why they got such excellent answers, then.
>
>If they could average 100M NPS, then a 3 minute search (40/2 average) would give
>18,000,000,000 {18 billion} nodes and 36 billion at 200 M (and I seem to recall
>a theoretical peak NPS rate of 1 billion).
>
>Since 6^12 = 2,176,782,336 [assuming a branching factor of 6 for pure
>alpha-beta with no pruning whatsoever, no null move, and with 36 moves average
>at each level] a 12 ply search should have taken only 21 seconds at 100 M NPS
>and 10.5 seconds at 200M.
>
>The math does not make sense to me.
Using the IBM logs, it appears that the branching factor was far smaller than 6.
With this program:
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>
char string[32767];
char curr[32767];
char prev[32767];
int main(void)
{
int first = 0;
double current,
ratio,
previous=0;
int index;
while (fgets(string, sizeof string, stdin)) {
char *where = strstr(string, "T=");
if (where == NULL)
continue;
where += 2;
index = 0;
while (isspace(*where)) where++;
while (isdigit(*where)) {
curr[index++] = *where++;
}
curr[index] = 0;
current = atof(curr);
if (first && previous) {
if (current == 1 && previous == 1)
{
puts("time diff too small");
goto update;
}
if (previous > current)
{
puts("move change or game change");
goto update;
}
ratio = current / previous;
printf("branch factor for %s/%s= %f\n", prev, curr, ratio);
}
update:
previous = current;
strcpy(prev, curr);
first = 1;
}
return 0;
}
Here is the output I received:
move change or game change
time diff too small
branch factor for 1/4= 4.000000
branch factor for 4/13= 3.250000
move change or game change
branch factor for 1/2= 2.000000
branch factor for 2/7= 3.500000
branch factor for 7/19= 2.714286
branch factor for 19/62= 3.263158
branch factor for 62/208= 3.354839
move change or game change
time diff too small
branch factor for 1/2= 2.000000
branch factor for 2/6= 3.000000
branch factor for 6/23= 3.833333
branch factor for 23/167= 7.260870
move change or game change
branch factor for 1/2= 2.000000
branch factor for 2/4= 2.000000
branch factor for 4/10= 2.500000
branch factor for 10/20= 2.000000
branch factor for 20/87= 4.350000
branch factor for 87/164= 1.885057
move change or game change
branch factor for 3/7= 2.333333
branch factor for 7/19= 2.714286
branch factor for 19/72= 3.789474
branch factor for 72/165= 2.291667
move change or game change
branch factor for 4/17= 4.250000
branch factor for 17/78= 4.588235
branch factor for 78/168= 2.153846
move change or game change
branch factor for 1/2= 2.000000
branch factor for 2/5= 2.500000
branch factor for 5/22= 4.400000
branch factor for 22/133= 6.045455
branch factor for 133/514= 3.864662
move change or game change
branch factor for 3/8= 2.666667
branch factor for 8/12= 1.500000
move change or game change
branch factor for 2/6= 3.000000
branch factor for 6/10= 1.666667
move change or game change
time diff too small
time diff too small
branch factor for 1/6= 6.000000
branch factor for 6/16= 2.666667
branch factor for 16/32= 2.000000
branch factor for 32/63= 1.968750
move change or game change
branch factor for 1/2= 2.000000
branch factor for 2/5= 2.500000
branch factor for 5/34= 6.800000
branch factor for 34/102= 3.000000
branch factor for 102/170= 1.666667
move change or game change
branch factor for 6/12= 2.000000
branch factor for 12/60= 5.000000
branch factor for 60/175= 2.916667
move change or game change
time diff too small
time diff too small
branch factor for 1/2= 2.000000
branch factor for 2/9= 4.500000
branch factor for 9/30= 3.333333
branch factor for 30/59= 1.966667
branch factor for 59/176= 2.983051
move change or game change
branch factor for 3/3= 1.000000
branch factor for 3/11= 3.666667
branch factor for 11/21= 1.909091
branch factor for 21/1683= 80.142857
move change or game change
branch factor for 1/2= 2.000000
branch factor for 2/8= 4.000000
branch factor for 8/29= 3.625000
branch factor for 29/128= 4.413793
branch factor for 128/376= 2.937500
move change or game change
branch factor for 1/2= 2.000000
branch factor for 2/3= 1.500000
branch factor for 3/15= 5.000000
branch factor for 15/34= 2.266667
branch factor for 34/83= 2.441176
branch factor for 83/167= 2.012048
move change or game change
branch factor for 6/22= 3.666667
branch factor for 22/96= 4.363636
branch factor for 96/161= 1.677083
move change or game change
branch factor for 1/3= 3.000000
branch factor for 3/10= 3.333333
branch factor for 10/36= 3.600000
branch factor for 36/73= 2.027778
move change or game change
branch factor for 1/3= 3.000000
branch factor for 3/7= 2.333333
branch factor for 7/37= 5.285714
branch factor for 37/162= 4.378378
move change or game change
branch factor for 10/101= 10.100000
branch factor for 101/153= 1.514851
branch factor for 153/395= 2.581699
branch factor for 395/760= 1.924051
move change or game change
time diff too small
branch factor for 1/3= 3.000000
branch factor for 3/7= 2.333333
branch factor for 7/21= 3.000000
branch factor for 21/91= 4.333333
branch factor for 91/162= 1.780220
move change or game change
branch factor for 5/15= 3.000000
branch factor for 15/43= 2.866667
branch factor for 43/164= 3.813953
branch factor for 164/864= 5.268293
branch factor for 864/938= 1.085648
move change or game change
branch factor for 6/15= 2.500000
branch factor for 15/230= 15.333333
move change or game change
branch factor for 4/34= 8.500000
move change or game change
branch factor for 1/3= 3.000000
branch factor for 3/6= 2.000000
branch factor for 6/20= 3.333333
branch factor for 20/67= 3.350000
branch factor for 67/159= 2.373134
move change or game change
branch factor for 1/8= 8.000000
branch factor for 8/64= 8.000000
branch factor for 64/143= 2.234375
move change or game change
time diff too small
time diff too small
time diff too small
branch factor for 1/2= 2.000000
branch factor for 2/4= 2.000000
branch factor for 4/10= 2.500000
branch factor for 10/19= 1.900000
branch factor for 19/111= 5.842105
branch factor for 111/153= 1.378378
move change or game change
branch factor for 4/9= 2.250000
branch factor for 9/84= 9.333333
branch factor for 84/134= 1.595238
branch factor for 134/326= 2.432836
move change or game change
branch factor for 5/16= 3.200000
branch factor for 16/69= 4.312500
branch factor for 69/146= 2.115942
move change or game change
branch factor for 2/9= 4.500000
branch factor for 9/53= 5.888889
branch factor for 53/193= 3.641509
move change or game change
branch factor for 1/4= 4.000000
branch factor for 4/19= 4.750000
branch factor for 19/41= 2.157895
branch factor for 41/58= 1.414634
branch factor for 58/63= 1.086207
branch factor for 63/77= 1.222222
branch factor for 77/135= 1.753247
branch factor for 135/153= 1.133333
move change or game change
branch factor for 1/3= 3.000000
branch factor for 3/6= 2.000000
branch factor for 6/20= 3.333333
branch factor for 20/84= 4.200000
branch factor for 84/343= 4.083333
branch factor for 343/847= 2.469388
move change or game change
time diff too small
branch factor for 1/2= 2.000000
branch factor for 2/5= 2.500000
branch factor for 5/20= 4.000000
branch factor for 20/60= 3.000000
branch factor for 60/153= 2.550000
move change or game change
branch factor for 1/14= 14.000000
branch factor for 14/51= 3.642857
branch factor for 51/145= 2.843137
branch factor for 145/153= 1.055172
move change or game change
branch factor for 2/5= 2.500000
branch factor for 5/13= 2.600000
branch factor for 13/62= 4.769231
branch factor for 62/245= 3.951613
branch factor for 245/539= 2.200000
move change or game change
branch factor for 1/2= 2.000000
branch factor for 2/15= 7.500000
branch factor for 15/28= 1.866667
branch factor for 28/73= 2.607143
branch factor for 73/154= 2.109589
move change or game change
branch factor for 1/6= 6.000000
branch factor for 6/21= 3.500000
move change or game change
branch factor for 3/8= 2.666667
branch factor for 8/39= 4.875000
branch factor for 39/112= 2.871795
branch factor for 112/195= 1.741071
move change or game change
branch factor for 2/8= 4.000000
branch factor for 8/22= 2.750000
branch factor for 22/96= 4.363636
branch factor for 96/163= 1.697917
move change or game change
branch factor for 3/7= 2.333333
branch factor for 7/15= 2.142857
branch factor for 15/42= 2.800000
branch factor for 42/157= 3.738095
move change or game change
branch factor for 1/5= 5.000000
branch factor for 5/23= 4.600000
branch factor for 23/70= 3.043478
branch factor for 70/831= 11.871429
move change or game change
move change or game change
move change or game change
branch factor for 1/4= 4.000000
branch factor for 4/15= 3.750000
branch factor for 15/47= 3.133333
branch factor for 47/160= 3.404255
move change or game change
branch factor for 1/3= 3.000000
branch factor for 3/12= 4.000000
branch factor for 12/84= 7.000000
branch factor for 84/162= 1.928571
move change or game change
branch factor for 1/3= 3.000000
branch factor for 3/18= 6.000000
branch factor for 18/158= 8.777778
branch factor for 158/269= 1.702532
move change or game change
time diff too small
branch factor for 1/4= 4.000000
branch factor for 4/7= 1.750000
branch factor for 7/29= 4.142857
branch factor for 29/83= 2.862069
branch factor for 83/689= 8.301205
move change or game change
move change or game change
branch factor for 3/5= 1.666667
branch factor for 5/17= 3.400000
branch factor for 17/67= 3.941176
branch factor for 67/98= 1.462687
branch factor for 98/111= 1.132653
move change or game change
branch factor for 1/3= 3.000000
branch factor for 3/3= 1.000000
branch factor for 3/7= 2.333333
branch factor for 7/46= 6.571429
branch factor for 46/130= 2.826087
branch factor for 130/168= 1.292308
move change or game change
branch factor for 1/5= 5.000000
branch factor for 5/20= 4.000000
branch factor for 20/49= 2.450000
branch factor for 49/169= 3.448980
move change or game change
branch factor for 4/13= 3.250000
branch factor for 13/39= 3.000000
branch factor for 39/209= 5.358974
move change or game change
branch factor for 2/6= 3.000000
branch factor for 6/13= 2.166667
branch factor for 13/45= 3.461538
branch factor for 45/129= 2.866667
branch factor for 129/150= 1.162791
move change or game change
time diff too small
branch factor for 1/3= 3.000000
branch factor for 3/3= 1.000000
branch factor for 3/13= 4.333333
branch factor for 13/22= 1.692308
branch factor for 22/53= 2.409091
branch factor for 53/145= 2.735849
branch factor for 145/172= 1.186207
move change or game change
branch factor for 2/12= 6.000000
branch factor for 12/29= 2.416667
branch factor for 29/67= 2.310345
move change or game change
time diff too small
branch factor for 1/2= 2.000000
branch factor for 2/8= 4.000000
branch factor for 8/25= 3.125000
branch factor for 25/151= 6.040000
branch factor for 151/397= 2.629139
move change or game change
branch factor for 3/8= 2.666667
branch factor for 8/13= 1.625000
branch factor for 13/29= 2.230769
branch factor for 29/47= 1.620690
branch factor for 47/187= 3.978723
move change or game change
branch factor for 1/3= 3.000000
branch factor for 3/11= 3.666667
branch factor for 11/27= 2.454545
branch factor for 27/65= 2.407407
branch factor for 65/229= 3.523077
branch factor for 229/311= 1.358079
branch factor for 311/538= 1.729904
move change or game change
time diff too small
time diff too small
time diff too small
time diff too small
branch factor for 1/2= 2.000000
branch factor for 2/3= 1.500000
branch factor for 3/7= 2.333333
branch factor for 7/21= 3.000000
branch factor for 21/49= 2.333333
branch factor for 49/177= 3.612245
move change or game change
branch factor for 1/7= 7.000000
branch factor for 7/14= 2.000000
branch factor for 14/30= 2.142857
branch factor for 30/41= 1.366667
branch factor for 41/124= 3.024390
branch factor for 124/159= 1.282258
branch factor for 159/1508= 9.484277
move change or game change
move change or game change
branch factor for 6/11= 1.833333
branch factor for 11/51= 4.636364
branch factor for 51/77= 1.509804
branch factor for 77/201= 2.610390
branch factor for 201/222= 1.104478
move change or game change
branch factor for 1/3= 3.000000
branch factor for 3/5= 1.666667
branch factor for 5/22= 4.400000
branch factor for 22/31= 1.409091
branch factor for 31/36= 1.161290
branch factor for 36/63= 1.750000
branch factor for 63/136= 2.158730
branch factor for 136/172= 1.264706
branch factor for 172/1387= 8.063953
move change or game change
move change or game change
move change or game change
move change or game change
branch factor for 12/36= 3.000000
branch factor for 36/73= 2.027778
branch factor for 73/204= 2.794521
move change or game change
time diff too small
time diff too small
branch factor for 1/2= 2.000000
branch factor for 2/3= 1.500000
branch factor for 3/11= 3.666667
branch factor for 11/24= 2.181818
branch factor for 24/50= 2.083333
branch factor for 50/74= 1.480000
branch factor for 74/135= 1.824324
branch factor for 135/304= 2.251852
move change or game change
branch factor for 1/2= 2.000000
branch factor for 2/5= 2.500000
branch factor for 5/8= 1.600000
branch factor for 8/19= 2.375000
branch factor for 19/28= 1.473684
branch factor for 28/52= 1.857143
branch factor for 52/93= 1.788462
branch factor for 93/106= 1.139785
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