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

Author: Stuart Cracraft

Date: 22:13:41 08/28/04

Go up one level in this thread


On August 27, 2004 at 23:32:11, Robert Hyatt wrote:

>On August 27, 2004 at 22:51:09, Stuart Cracraft wrote:
>
>>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)
>>
>>Also, is that 16 ply in 38.96 seconds?
>>
>>Stuart
>

Nice coding -- I assume the Crafty that's been entered in any public
events is no where near that configuration in speed?

Stuart

>Yes.  Quad opteron 2.4ghz



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