Mate in 4 test...

[rightrook]

[d]8/3KpkPp/7B/8/8/8/8/8 w - - 0 1

Some of my programs (such as Junior 5) set at infinite mode have trouble with this mate in 4....!

regards

Robert

[michiguel]

[d]8/3KpkPp/7B/8/8/8/8/8 w - - 0 1

Some of my programs (such as Junior 5) set at infinite mode have trouble with this mate in 4....!

regards

Robert

Gaviota (AMD X2 +4600) sees it quickly.

Miguel

Code: Select all

setboard 8/3KpkPp/7B/8/8/8/8/8 w - - 0 1
d
+-----------------+
| . . . . . . . . |
| . . . K p k P p |
| . . . . . . . B |
| . . . . . . . . |    Castling: 
| . . . . . . . . |    ep: -
| . . . . . . . . |
| . . . . . . . . |
| . . . . . . . . | [White]
+-----------------+

analyze
        32   1:      0.0    +1.55  Kd7-d8   
       269   2:      0.0    +1.74  Kd7-c7   e7-e5    Kc7-d6   
       815   3:      0.0    +1.92  Kd7-c6   e7-e6    Kc6-d6   
      3501   4:      0.0    +1.78  Kd7-c6   Kf7-g8   Kc6-d5   Kg8-f7   
      8758   5       0.0      :-)  g7-g8=Q  
      8805   5       0.0      :-)  g7-g8=Q  
      8853   5       0.0      :-)  g7-g8=Q  
     33394   5       0.2      :-)  g7-g8=Q  
     34737   5:      0.2   +Mat_4  g7-g8=Q  Kf7xg8   Kd7-e6   Kg8-h8   
                                   Ke6-f7   e7-e5    Bh6-g7   
     36712   6:      0.2   +Mat_4  g7-g8=Q  Kf7xg8   Kd7-e6   <-transp 
     40706   7:      0.2   +Mat_4  g7-g8=Q  Kf7xg8   Kd7-e6   <-transp 

[Graham Banks]

Hi Miguel,

any chance of a new Gaviota?

Regards, Graham.

[sje]

Symbolic, 50 milliseconds and without tablebases:

Code: Select all

[SI] (01) Starting the first iteration
[SI] (01) ASRW Centroid: +3.972   Window: [+3.638 +4.305]   A/B Adj: 0/0
[PV] 1. Kd8 e5   Score: +3.905
[PV] 1. Kc6 e5   Score: +3.929
[SI] (01) Nodes: 167   Total: 202
[SI] (01) Times: [C: 00.00  U: 00.00]   Total: [C: 00.01  U: 00.01]
[SI] (01) F/P: 23.0918 KHz/43.3054 us   Mean: 13.547 KHz/73.8168 us
[SI] (01) Utilization rate: 1   Mean: 1
[SI] (01) Finished iteration one
[SI] (02) Starting the second iteration
[SI] (02) ASRW Centroid: +3.929   Window: [+3.595 +4.262]   A/B Adj: 0/0
[PV] 1. Kc6 e6 2. Kd6   Score: +3.932
[PV] 1. Kc7 e5 2. Kd6 e4   Score: +3.932
[SI] (02) Nodes: 413   Total: 615
[SI] (02) Times: [C: 00.00  U: 00.00]   Total: [C: 00.01  U: 00.01]
[SI] (02) F/P: 87.4259 KHz/11.4383 us   Mean: 30.8101 KHz/32.4569 us
[SI] (02) Utilization rate: 1   Mean: 1
[SI] (02) Finished iteration two
[SI] (03) Starting the third iteration
[SI] (03) ASRW Centroid: +3.932   Window: [+3.598 +4.265]   A/B Adj: 0/0
[PV] 1. Kc7 Kg8 2. Kc6 e5   Score: +3.751
[PV] 1. Kc6 Kg8 2. Kd5 Kf7   Score: +4.160
[PV] 1. g8=Q+ Kxg8 2. Ke6 Kh8 3. Kf7 e5   Score: +4.265
[SI] (03) Fail high; restarting the third iteration
[SI] (03) ASRW Centroid: +3.932   Window: [+3.598 +5.265]   A/B Adj: 0/1
[PV] 1. g8=Q+ Kxg8 2. Ke6 Kh8 3. Kf7 e5   Score: +5.265
[SI] (03) Fail high; restarting the third iteration
[SI] (03) ASRW Centroid: +3.932   Window: [+3.598 +6.598]   A/B Adj: 0/2
[PV] 1. g8=Q+ Kxg8 2. Ke6 Kh8 3. Kf7 e5   Score: +6.598
[SI] (03) Fail high; restarting the third iteration
[SI] (03) ASRW Centroid: +3.932   Window: [+3.598 PosInf]   A/B Adj: 0/3
[PV] 1. g8=Q+ Kxg8 2. Ke6 Kh8 3. Kf7 e5 4. Bg7#   Score: MateIn4
[SI] (03) Nodes: 5,272   Total: 5,887
[SI] (03) Times: [C: 00.02  U: 00.02]   Total: [C: 00.04  U: 00.04]
[SI] (03) F/P: 214.737 KHz/4.65687 us   Mean: 131.245 KHz/7.61933 us
[SI] (03) Utilization rate: 1   Mean: 1
[SI] (03) Finished iteration three
[SI] (04) Starting the fourth iteration
[SI] (04) ASRW Centroid: MateIn4   Window: [MateIn5 PosInf]   A/B Adj: 0/0
[PV] 1. g8=Q+ Kxg8 2. Ke6 Kh8 3. Kf7 e5 4. Bg7#   Score: MateIn4
[SI] (04) Nodes: 1,400   Total: 7,287
[SI] (04) Times: [C: 00.00  U: 00.00]   Total: [C: 00.04  U: 00.04]
[SI] (04) F/P: 399.315 KHz/2.50429 us   Mean: 149.84 KHz/6.6738 us
[SI] (04) Utilization rate: 1   Mean: 1
[SI] (04) Finished iteration four
[SI] (05) Starting the fifth iteration
[SI] (05) ASRW Centroid: MateIn4   Window: [MateIn5 PosInf]   A/B Adj: 0/0
[PV] 1. g8=Q+ Kxg8 2. Ke6 Kh8 3. Kf7 e5 4. Bg7#   Score: MateIn4
[SI] (05) Nodes: 2,816   Total: 10,103
[SI] (05) Times: [C: 00.00  U: 00.00]   Total: [C: 00.05  U: 00.05]
[SI] (05) F/P: 723.535 KHz/1.3821 us   Mean: 191.399 KHz/5.22469 us
[SI] (05) Utilization rate: 0.976173   Mean: 1
[SI] (05) Finished iteration five
[TT] Eval:  P:3,029 M:1,231 R:0.406405 S:1,798 U:0.000857353
[TT] Hint:  P:48 M:0 R:0 S:48 U:0.00585938
[TT] Main:  P:6,181 M:3,265 R:0.528232 S:4,383 U:0.00269794
[TT] Pawn:  P:1,798 M:1,764 R:0.98109 S:34 U:0.0001297
[TT] TBPr:  P:236 M:0 R:0 S:0 U:0
[ST] Nodes: 10,103   Times: [C: 00.05  U: 00.05]
[TB] Tablebase probe count: 0
[ST] F/P: 188.39 KHz/5.30813 us
[ST] Utilization rate: 1
[ST] PV: 1. g8=Q+ Kxg8 2. Ke6 Kh8 3. Kf7 e5 4. Bg7#   Score: MateIn4
[ST] Depth: 6   Maximum ply: 9   Termination: EarlyMate

[michiguel]

Hi Miguel,

any chance of a new Gaviota?

Regards, Graham.

Yes, I am working on it. I do not know when, but whenever I have a version worth releasing, I will do it.

Miguel

[Roman Hartmann]

Thanks for posting this position. Programs without a verification-search after a null-move will fail here. Disabling null-move in positions like that will solve the problem as well.

I was just able to fix a flaw in my verification-search because of that position

best regards
Roman

[rightrook]

Thank you Roman...

I just thought it might be helpful to someone out there....



regards

Robert