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Subject: counter example

Author: Vincent Diepeveen

Date: 13:05:21 10/13/02

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On October 13, 2002 at 15:55:05, Vincent Diepeveen wrote:

hello, you can also see it from the other side.

suppose the hardware search (which theoretical is impossible)
would be a+b.

In that case the only way to search is to start with:

1,2,3,4,5,6,7,8,9,10,11,12,13 ply. If you skip an iteration with
so many extensions then you get dicked completely.

If you look with me in game 1 the first output:

 3(4) -25  T=0
Bc8g4 ph2h3
 4(5) -25  T=0
Bc8g4 ph2h3
 5(5)[Bg4](-22) -22  T=0
Bc8g4 bf1g2
 6(5)[Bg4](-23) -23  T=0
Bc8g4 nf3e5 Ng8f6 ne5g4B
 7(5) #[Bg4](-18) -18  T=1
Bc8g4 bf1g2 Ng8f6 nf3e5 Pe7e6
 8(6) #[Bg4](-21) -21  T=1
Bc8g4 bf1g2 Ng8f6 o-o Pe7e6 ph2h3
 9(6) #[Bg4](-12) -12  T=4
Bc8g4 nf3e5 Bg4e6 bf1g2 Pg7g6 o-o
10(6)<ch> 'g3'
[0 sec (main.c:6581)] -12  T=13
Bc8g4 nf3e5 Bg4f5 pd2d4 Pe7e6 bc1f4

from 3(4) it jumps to 4(5) that's from 7 to 9 ply.
And after a few seconds already it has 10(6) which would be 16 ply??
that's impossible to search in 16 seconds with 100 million nodes a second.

Please follow knuth. impossible right.

Look at the mainline length. At 5(5) it shows only a 2 ply mainline.
If that's 5 ply in total from which say 3 ply in hardware (up to 5 ply
maximum, but of course at 5 ply you don't get that) then it is logical
to get a 2 ply  mainline.

If i search 10 ply from which 5 ply in software and i get a 2 ply mainline,
then i cry murder, rape and FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF. But i am
not happy.

It is missing 3 ply then.

Well as we know it is not missing 3 ply there.

6(5) Bc8g4 nf3e5 Ng8f6 ne5g4B

the ne5g4 gets extended there it is an important capture.

10(6) Bc8g4 nf3e5 Bg4e6 bf1g2 Pg7g6 o-o

up to 6 ply in hardware. Suppose you do just 4 ply in software.
How do you get 480 processors *ever* to work then?

Answer: NOT.

A 4 ply tree in mainline is very small. Everything from hashtable.

Answer: it was doing 6 ply searches there and had most searches like 4 ply
searches in hardware.

Makes sense. You can perhaps get a 50 cpu's or so to work with a 6 ply
search. *at most*.

No way to get 50 cpu's to work with a 4 ply software search.

>On October 13, 2002 at 15:47:43, Jeremiah Penery wrote:
>
>>On October 13, 2002 at 14:14:13, Vincent Diepeveen wrote:
>>
>>>On October 13, 2002 at 13:50:24, Jeremiah Penery wrote:
>>>
>>>for any chessprogrammer it is very clear Jeremiah.
>>>
>>>It's 12 ply and the 6 only means that the hardware search can
>>>be up to 6 ply within that 12 ply nominal.
>>
>>For the millionth time, explain 4(5) then.
>
>it's a lot easier when you try to imagine how you would start
>a search. Look at 4 ply you want to involve other cpu's too.
>
>You have 480 chess chips. 9 out of 10 is idling anyway
>(we know this because everyone says it was capable in theory
>to get a billion nodes a second in theory, yet it got only
>126 million nodes on average; there is no discussion here)
>
>you want to use as many cpu's as possible. So at the root you
>ask a few chips. Of course you must take into account extensions too.
>
>If a 4 ply search for this chip is too much, then you split it. and
>split it. Giving a 2 ply search to chip A, and a 3 ply search to
>chip B.
>
>The 5 in short has no meaning here.
>
>You can see that the mainlines at the start of the game (so before
>hashtables are filled with a lot of info that extends lines)
>that the lines it gives at 4 , 5 , 6 ply is usually 1 ply long.



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