Author: Robert Hyatt
Date: 19:52:20 04/26/01
Go up one level in this thread
On April 26, 2001 at 20:29:07, Uri Blass wrote:
>On April 26, 2001 at 20:06:38, Robert Hyatt wrote:
>
>>On April 26, 2001 at 17:30:11, Uri Blass wrote:
>>
>>>On April 26, 2001 at 17:24:09, Robert Hyatt wrote:
>>>
>>>>On April 26, 2001 at 16:57:53, Christophe Theron wrote:
>>>>
>>>>>
>>>>>
>>>>>If it is just that, then there are ways to avoid these problems. Expensive, but
>>>>>less expensive than brute force.
>>>>>
>>>>>The problem I abhor is when my program gets oursearched. This by far outweigths
>>>>>any other minor problem. Brute force always has this problem, not just in one
>>>>>game out of 1000.
>>>>>
>>>>>
>>>>>
>>>>> Christophe
>>>>
>>>>
>>>>Maybe that was Hsu's point. At 200M nodes per second you probably won't
>>>>get outsearched if you search every node twice. :)
>>>
>>>Hsu is wrong.
>>>
>>>Deeper blue made a tactical mistake in the second game against kasparov because
>>>it did not search deep enough.
>>>
>>>It did not see that the final position is drawn and it proves that search is
>>>important also at 200M nodes per second.
>>>
>>>Uri
>>
>>
>>By that definition every lost game makes a tactical mistake.
>
>The point is that it is not a mistake because of a zunzwang so recursive null
>move could help to find the right move faster.
>
>Deeper blue
> Since _nobody_
>>has shown a draw in that position with a computer, I can personally forgive
>>deep blue as well.
>
>I remember that Diep could see enough in order to play 44.Kh1 and not 44.Kf1 in
>the position some plies before the drawn position.
>
>I guess that other programs can also do the same if you give them enough time.
>
>Here is the relevant position
>[D]R7/1r3kp1/1qQb1p1p/1p1PpP2/1Pp1B3/2P4P/6P1/6K1 w - - 0 1
>
>Deeper blue searched 192 seconds and played 44.Kf1
>I am interested to know what programs can see after 192*200,000,000 nodes.
>
>Uri
Here is crafty's output on my notebook. Lots of mind changing...
I will guarantee you that if a program plays Kh1 over Kf1 it is
_not_ because it is avoiding a draw. They are not going to see that
from here...
The following is the best 4 moves and scores, searched for
60 seconds. NOthing marks the first 2 as being much different.
the third is close...
({14:+1.85} 1. Kf1 Rb8 2. Ra6 Qxc6 3. dxc6 Kf8 4. Ra7 Rc8 5. Rb
7 h5 6. Rxb5 Ke7 7. Ra5 Rc7 8. Ke2 h4 $18)
({14:+1.88} 1. Kh2 Rb8 2. Ra6 Qxc6 3. dxc6 Kf8 4. Ra7 Rd8 5. Rb
7 Rc8 6. Rxb5 $18)
({14:+1.54} 1. Kh1 Rb8 2. Ra6 Qxc6 3. dxc6 Kf8 4. Ra7 Rc8 5. Rb
7 Ra8 6. Rxb5 Ra1+ 7. Kh2 Re1 8. Rd5 Bxb4 9. cxb4 Rxe4 $18)
({14:+0.39} 1. Qxb6 Rxb6 2. Ra7+ Kf8 3. Kf1 Bb8 4. Rd7 Bd6 5. K
e2 Be7 6. Ra7 Bd6 7. h4 Rb8 $14)
I don't want to even talk about Diep or any other program playing Kh1 or
not playing Kf1 until I see real PVs and scores to prove they know that Kf1
leads to a draw...
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