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Subject: Re: IQ-Test Position 166, any hint how to solve it ?

Author: Stuart Cracraft

Date: 19:47:56 08/27/04

Go up one level in this thread


On August 26, 2004 at 11:39:31, Robert Hyatt wrote:

>On August 25, 2004 at 12:52:46, Volker Böhm wrote:
>
>>
>>Hi,
>>
>>the following position of the iq - test (position 166) cannot be solved from
>>spike in reasonalbe time (> 2h):
>>
>>r4r1k/6pp/3p3b/1p1Npb2/3nB2q/2N3P1/PP3P1P/R2Q1RK1 b - - 0 1
>>
>>(The move to find is Qxe4)
>>
>>The reason is a nullmove-problem. After the queen-sac there are many moves that
>>leads to a mate-thread. But one queen back spike tends to prune because of
>>nullmove result.
>>
>>I tested the position with fritz 8, he solves it in 8 ply in nearly no time.
>>(PRODEO NEEDS 7 Ply, Ruffian 1.01 11 Ply).
>>
>>Are there non commercial engines that solves this position too in a short amount
>>of time?
>>Maybe the author of this engine would be so kind to explain the rule that solves
>>the nullmove-problem.
>>
>>Thanks Volker
>
>
>Here is my output:
>
>                8->   0.23  -0.16   1. ... Qh3 2. Bg2 Qg4 3. Ne3 Qxd1 4.
>                                    Rfxd1 Rac8 5. Nxf5 Rxf5 6. Nd5 (s=2)
>                9     0.47  -0.03   1. ... Qh3 2. Bxf5 Qxf5 3. f4 Rab8
>                                    4. fxe5 Qxe5 5. Qd3 Rxf1+ 6. Qxf1 Be3+
>                                    7. Nxe3 Qxe3+ 8. Qf2
>                9     0.68     -1   1. ... Qxe4!!
>                9     0.71  -1.01   1. ... Qxe4 2. Nxe4 Bxe4 3. Nc3 Bf3
>                                    4. Qd3 b4 5. a4 bxc3 6. bxc3
>                9->   0.71  -1.01   1. ... Qxe4 2. Nxe4 Bxe4 3. Nc3 Bf3
>                                    4. Qd3 b4 5. a4 bxc3 6. bxc3 (s=6)
>               10     0.75  -1.01   1. ... Qxe4 2. Nxe4 Bxe4 3. Nc3 Bf3
>                                    4. Qd3 b4 5. a4 bxc3 6. bxc3 (s=5)
>               10->   0.85  -1.01   1. ... Qxe4 2. Nxe4 Bxe4 3. Nc3 Bf3
>                                    4. Qd3 b4 5. a4 bxc3 6. bxc3 (s=3)
>               11     0.97  -1.28   1. ... Qxe4 2. Nxe4 Bxe4 3. Nc3 Bf3
>                                    4. Qd3 b4 5. Rfe1 bxc3 6. bxc3 Ra3
>                                    (s=2)
>               11->   1.19  -1.28   1. ... Qxe4 2. Nxe4 Bxe4 3. Nc3 Bf3
>                                    4. Qd3 b4 5. Rfe1 bxc3 6. bxc3 Ra3
>                                    (s=3)
>               12     1.36  -1.22   1. ... Qxe4 2. Nxe4 Bxe4 3. Nc3 Bf3
>                                    4. Qd3 b4 5. Rfe1 bxc3 6. bxc3 Ra3
>                                    7. Rab1 (s=2)
>               12->   2.57  -1.22   1. ... Qxe4 2. Nxe4 Bxe4 3. Nc3 Bf3
>                                    4. Qd3 b4 5. Rfe1 bxc3 6. bxc3 Ra3
>                                    7. Rab1 (s=3)
>               13     3.00  -1.25   1. ... Qxe4 2. Nxe4 Bxe4 3. Nc3 Bf3
>                                    4. Qd3 b4 5. Rfe1 bxc3 6. bxc3 Ra3
>                                    7. Qc4 Nc2 (s=2)
>               13->   4.70  -1.25   1. ... Qxe4 2. Nxe4 Bxe4 3. Nc3 Bf3
>                                    4. Qd3 b4 5. Rfe1 bxc3 6. bxc3 Ra3
>                                    7. Qc4 Nc2 (s=3)
>               14     6.08  -1.47   1. ... Qxe4 2. Nxe4 Bxe4 3. Nc3 Bf3
>                                    4. Qd3 b4 5. Rfb1 bxc3 6. bxc3 Ne2+
>                                    7. Kf1 Rad8 8. Rb6 e4 (s=2)
>               14->  18.31  -1.47   1. ... Qxe4 2. Nxe4 Bxe4 3. Nc3 Bf3
>                                    4. Qd3 b4 5. Rfb1 bxc3 6. bxc3 Ne2+
>                                    7. Kf1 Rad8 8. Rb6 e4 (s=3)
>               15    22.98  -1.67   1. ... Qxe4 2. Nxe4 Bxe4 3. Nc3 Bf3
>                                    4. Qd3 b4 5. Rae1 bxc3 6. bxc3 Ra3
>                                    7. Qc4 Nc2 8. Rb1 Bd2 (s=2)
>               15->  32.85  -1.67   1. ... Qxe4 2. Nxe4 Bxe4 3. Nc3 Bf3
>                                    4. Qd3 b4 5. Rae1 bxc3 6. bxc3 Ra3
>                                    7. Qc4 Nc2 8. Rb1 Bd2 (s=3)
>               16    38.96  -1.54   1. ... Qxe4 2. Nxe4 Bxe4 3. Nc3 Bf3
>                                    4. Qd3 b4 5. Rae1 bxc3 6. bxc3 Ra3
>                                    7. Qc4 Nc2 8. Rb1 Bd2 9. Qe6 (s=2)

In your output, what does s=2 and s=3 mean?
How about !! ? And is the -value relative to the
side on move? Finally, is this your 4-cpu Xeon?
If so, what speed are the chips and what are
the characteristics that distinguish between
the Xeon and a regular Intel chip?

Stuart




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