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Subject: Re: Some more test position with the same team(Nxa1 bad)

Author: Eelco de Groot

Date: 21:54:48 10/21/00

Go up one level in this thread


On October 21, 2000 at 20:34:33, Paulo Soares wrote:

>On October 21, 2000 at 19:26:23, Chessfun wrote:
>
>>On October 21, 2000 at 19:14:14, Uri Blass wrote:
>>
>>>White is losing in this line and has no advantage but programs have the illusion
>>>that white has advantage or at least equality and it pushes them to play the
>>>wrong Bxc4.
>>>
>>>Some programs do not play Bxc4 at tournament time control because the illusion
>>>is too deep for them to see it.
>>>
>>>The fact that tiger never considers Bxc4 as best may be a result of right
>>>evaluation or result of not seeing the illusion because it is too deep.
>>
>>
>>I think it is evaluation not as posted 1) but 2).
>>
>>
>>>My experience with chess programs tells me that the common case with programs is
>>>the case that the illusion is too deep for the programs to see.
>>>
>>>It can be proved by giving them the position before Ne5 and checking if they see
>>>positive evaluation.
>>
>>
>>Both Tiger's are negative before Ne5 and even forcing Bxc4 is a -1.00
>>swing from what it wants to play. Which is why I say 2).
>>
>>
>>>Crafty17.11 does not see positive evaluation but it can see evaluation that is
>>>close to 0 and it may push it to play Bxc4(I do not know,I remember that an old
>>>version of Crafty could play the wrong Bxc4 after a long time).
>>>Hiarcs7.32 can see positive evaluation only to fail low later and the same for
>>>other programs.
>>
>>As I said Tiger and Gambit seeing it as a -1.00 swing they fail immediately
>>and it seems to me the reason is they know by evaluation or knowledge that Bxc4
>>is wrong.
>>
>>Sarah.
>
>Rebel Tiger 12.e select Bxc4 in my PIII-450 HT=64Mb.
>I believe that most of the programs will select Bxc4 and later to discard it,
>like Uri wrote previously. Perhaps "new Tigers" also selects Bxc4 if you give
>more time.
>
>Paulo
>
>00:00:00.6	0,02	7	41576	Qxd4  Qxd4  Nxd4  b5  Be3  a6
>00:00:01.9	-0,18	8	101591	Qxd4  Qxd4  Nxd4  b5  Bf4  a6  Bxb8  Rxb8  Nxc6
>00:00:01.1	-0,16	8	138166	Nxd4
>00:00:02.4	-0,10	8	214796	Nxd4  b5
>00:00:07.6	-0,06	9	707472	Nxd4  Nf6  e5  Qe7  Bxc4  Qxe5+  Be3  Ng4  Nf3  Nxe3
>Nxe5  Nxd1  Rxd1
>00:00:31.1	-0,12	10	3201260	Nxd4  b5  Bf4  Nd7  f3
>00:00:31.2	-0,10	10	3278507	Qxd4
>00:00:33.8	0,00	10	3398686	Qxd4  Qxd4  Nxd4  b5  Bf4  b4
>00:00:48.7	-0,08	11	5132242	Qxd4  Qxd4  Nxd4  b5  Bf4  Bb7  e5  Nd7
>00:01:41.1	0,00	12	11305699	Qxd4  Qxd4  Nxd4  b5  Be2  Nf6  0-0
>00:03:34.2	0,00	13	24388883	Qxd4  Qxd4  Nxd4  b5  a4  b4  Nd1  Ba6  f3  c5
>00:18:16.9	0,02	13	139595658	Bxc4


Hi guys,

If Q5T isn't totally off here then in second position 1.Bxc4 is still playable
because after 1. ..dxc3 can follow 2.Bxf7+.
I haven't checked it, not so good with tactics, I'll leave that to you all I
think!

Regards, Eelco

Running way in background:

Rebel Engine for ECTool. (c) Ed Schröder

Engine version   :  REBEL CENTURY 2
Rebel personality :  "Q5T Experimental"
Opening book file :  REBEL.MVS
Hash table size  :  4 MB
Analysis mode   :  Analyzing next move
Refresh interval : 500 ms

Game begin

00:00  03.01  -0.04  1.Nxd4 Bc5 2.Be3
00:00  05.00  -0.17  1.Qxd4 Qxd4 2.Nxd4 b5 3.Bd2 Nf6
00:01  05.01  -0.11  1.Nxd4 b5 2.a3 Bc5 3.Be3
00:02  06.01  -0.18  1.Qxd4
00:03  06.01  0.15  1.Qxd4 Qxd4 2.Nxd4 b5 3.Bf4 Nd7 4.Nxc6
00:03  07.00  -0.07  1.Qxd4 Qxd4 2.Nxd4 b5 3.Bf4 b4 4.Na4 Nf6 5.Bxc4
00:10  08.00  -0.20  1.Qxd4 Qxd4 2.Nxd4 b5 3.f4+ b4 4.Nd1 c5 5.Nf3
00:40  09.00  -0.13  1.Qxd4 Qxd4 2.Nxd4 b5 3.f4 Nf6 4.a3 Bc5 5.Be3 a5
02:13  09.03  -0.13  1.Bxc4
02:20  09.03  0.14  1.Bxc4 b5 2.Nxb5 Bb4+ 3.Bd2 Bxd2+
03:30  10.00  0.20  1.Bxc4 b5 2.Nxb5 Bb4+ 3.Bd2 Bxd2+
06:31  11.00  0.14  1.Bxc4 b5 2.Nxb5 Bb4+ 3.Bd2 Bxd2+


Last Move : 1... dxc3 (White to play)

00:00  01.09  2.90  2.Bxf7+ Ke7
00:00  02.00  2.53  2.Bxf7+ Ke7 3.Bg5+ Nf6 4.Bxf6+ gxf6
00:01  03.00  0.03  2.Bxf7+ Ke7 3.Qb3 Qd3 4.bxc3 Qxe4+
00:02  04.00  1.17  2.Bxf7+ Ke7 3.Qb3 Qb6 4.Bxg8 Qxb3 5.Bxb3
00:06  05.00  0.71  2.Bxf7+ Ke7 3.Qb3 Qb6 4.Bxg8 Qxb3 5.Bxb3 cxb2 6.Bxb2
00:23  06.00  0.39  2.Bxf7+ Ke7 3.Qb3 Qb6 4.Bxg8 Qxb3
01:30  07.00  0.59  2.Bxf7+ Ke7 3.Qb3 Nf6 4.bxc3 Qa5 5.e5
06:32  08.00  0.59  2.Bxf7+ Ke7 3.Qb3 Qb6 4.Bxg8 Qxb3 5.Bxb3 cxb2 6.Bxb2 Bg4
11:40  09.00  0.87  2.Bxf7+ Ke7 3.Qb3 Qb6 4.Bxg8 Qxb3 5.Bxb3 cxb2 6.Bxb2




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