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.