Zugzwang Collection

[Carlos Ylich]

Great Collection King !!
Good Job.
Thanks,
Carlos Ylich

[kingliveson]

The 'thanks' belong to the gentlemen who contributed the positions and links.

[Adam Hair]

Some engines that find the bishop underpromotion:

Houdini 1.5a
Robbolito 0.10
Stockfish 2.2.2
Crafty 23.4
Tarrasch Toy Engine 0.906
AdroitChess 0.3

Engines that do not:
Komodo 3 and 4
TJChess 1.1

Engine that refuses to analyze that stupid position :
Gaviota 0.84

[Adam Hair]

From Chess.com:

Podgaets, Mikhail vs. Dvoretzky, Mark
URSS
1974
0-1

8/p5k1/Pp1p2p1/2pP4/6nq/5r2/1PP2PQ1/5RKB w - - 0 1

[Adam Hair]

Some engines that find the bishop underpromotion:

Houdini 1.5a
Robbolito 0.10
Stockfish 2.2.2
Crafty 23.4
Tarrasch Toy Engine 0.906
AdroitChess 0.3

Engines that do not:
Komodo 3 and 4
TJChess 1.1

Engine that refuses to analyze that stupid position :
Gaviota 0.84

I forgot to add that Rybka 2.2n2 also misses the bishop underpromotion. Like Komodo, it wants to promote the pawn to a queen.

Code: Select all

Rybka 2.2n2 32 bit
   
      2   00:00             27   864    0.00   Kb8-c7
      3   00:00             32   1,024    0.00   Kb8-c7
      4   00:00             38   1,216    0.00   Kb8-c7
      5   00:00             53   1,130    0.00   Kb8-c7 b7xa8Q
      6   00:00             72   1,536    0.00   Kb8-c7 b7xa8Q
      7   00:00             98   2,090    0.00   Kb8-c7 b7xa8Q
      8   00:00            141   3,008    0.00   Kb8-c7 b7xa8Q
      9   00:00            206   3,348    0.00   Kb8-c7 b7xa8Q
     10   00:00            319   5,185    0.00   Kb8-c7 b7xa8Q
     11   00:00            490   6,351    0.00   Kb8-c7 b7xa8Q
     12   00:00            744   9,643    0.00   Kb8-c7 b7xa8Q
     13   00:00          1,042   11,351    0.00   Kb8-c7 b7xa8Q
     14   00:00          1,377   15,000    0.00   Kb8-c7 b7xa8Q
     15   00:00          1,801   19,619    0.00   Kb8-c7 b7xa8Q
     16   00:00          2,383   22,183    0.00   Kb8-c7 b7xa8Q
     17   00:00          3,099   28,848    0.00   Kb8-c7 b7xa8Q
     18   00:00          4,086   33,206    0.00   Kb8-c7 b7xa8Q
     19   00:00          5,128   41,675    0.00   Kb8-c7 b7xa8Q
     20   00:00          6,345   46,080    0.00   Kb8-c7 b7xa8Q
     21   00:00          7,708   50,273    0.00   Kb8-c7 b7xa8Q
     22   00:00          9,447   61,616    0.00   Kb8-c7 b7xa8Q
     23   00:00         10,915   64,606    0.00   Kb8-c7 b7xa8Q
     24   00:00         13,064   71,157    0.00   Kb8-c7 b7xa8Q
     25   00:00         15,770   79,159    0.00   Kb8-c7 b7xa8Q
     26   00:00         18,967   88,685    0.00   Kb8-c7 b7xa8Q
     27   00:00         22,756   99,158    0.00   Kb8-c7 b7xa8Q
     28   00:00         26,719   109,005    0.00   Kb8-c7 b7xa8Q
     29   00:00         31,887   115,788    0.00   Kb8-c7 b7xa8Q
     30   00:00         38,816   126,989    0.00   Kb8-c7 b7xa8Q
     31   00:00         47,267   140,701    0.00   Kb8-c7 b7xa8Q
     32   00:00         56,703   148,500    0.00   Kb8-c7 b7xa8Q
     33   00:00         68,660   160,520    0.00   Kb8-c7 b7xa8Q
     34   00:00         83,405   170,472    0.00   Kb8-c7 b7xa8Q
     35   00:00        125,436   167,684    0.00   Kb8-c7 b7xa8Q
     36   00:01        149,418   174,662    0.00   Kb8-c7 b7xa8Q
     37   00:01        179,527   180,940    0.00   Kb8-c7 b7xa8Q
     38   00:01        214,877   185,213    0.00   Kb8-c7 b7xa8Q
     39   00:01        271,603   187,287    0.00   Kb8-c7 b7xa8Q
     40   00:02        331,458   155,124    0.00   Kb8-c7 b7xa8Q
     41   00:04        625,626   160,120    0.00   Kb8-c7 b7xa8Q
     42   00:04        772,277   162,718    0.00   Kb8-c7 b7xa8Q
     43   00:05        935,517   164,797    0.00   Kb8-c7 b7xa8Q
     44   00:07      1,247,922   164,547    0.00   Kb8-c7 b7xa8Q
     45   00:09      1,490,194   166,081    0.00   Kb8-c7 b7xa8Q
     46   00:13      2,211,923   169,333    0.00   Kb8-c7 b7xa8Q
     47   00:17      2,849,089   169,738    0.00   Kb8-c7 b7xa8Q

[BB+]

I forgot to add that Rybka 2.2n2 also misses the bishop underpromotion. Like Komodo, it wants to promote the pawn to a queen.

What I want to see is an engine that promotes to a queen/rook in its PV, but gives this a mate score (rather than a stalemate score).

[Adam Hair]

Some engines that find the bishop underpromotion:

Houdini 1.5a
Robbolito 0.10
Stockfish 2.2.2
Crafty 23.4
Tarrasch Toy Engine 0.906
AdroitChess 0.3

Engines that do not:
Komodo 3 and 4
TJChess 1.1

Engine that refuses to analyze that stupid position :
Gaviota 0.84

Gaviota gave no output because there is only one move. Miguel made a change to force it to give the PV, and it also finds the bishop underpromotion.

[Uly]

I forgot to add that Rybka 2.2n2 also misses the bishop underpromotion.

All versions of Rybka are going to miss Bishop under-promotions in the PV as it's a feature that Vas never implemented.

[Adam Hair]

I forgot to add that Rybka 2.2n2 also misses the bishop underpromotion.

All versions of Rybka are going to miss Bishop under-promotions in the PV as it's a feature that Vas never implemented.

Yeah. It occurred to me afterwards that this was well-known behavior for Rybka.

[noctiferus]

Yes. Vas always rejected the idea of including this feature, because it had a small impact on Elo gain due to rare occurence, and was costing too much in terms of speed.
Can't find the specific links, but it was a long discussion on Rybka forum...
Maybe Uly can be more precise.