Rybka couldn't solve this..Any sggestions which engine can?

[Dr.Joy]

I had a lot of fun solving this study with my friend..It is hard but really brilliant, and we could solve it within around 30 minutes.

But trying it with Deep Rybka 3 - 64 bit on my Q6600 - 4GB Ram for over 10 hours on infinite analysis mode , Rybka had no idea what was going on.

I will not spoil the beautiful study by giving the solution but I will give it later. The first move is Ba3 which is not difficult of coarse but I would like to know if any engine can crack this study.


6KB/6P1/6b1/8/6P1/8/P2k2P1/2b5 b - - 0 1


(Sorry I don't know how to post a diagram)

[krazyken]

I had a lot of fun solving this study with my friend..It is hard but really brilliant, and we could solve it within around 30 minutes.

But trying it with Deep Rybka 3 - 64 bit on my Q6600 - 4GB Ram for over 10 hours on infinite analysis mode , Rybka had no idea what was going on.

I will not spoil the beautiful study by giving the solution but I will give it later. The first move is Ba3 which is not difficult of coarse but I would like to know if any engine can crack this study.


[D] 6KB/6P1/6b1/8/6P1/8/P2k2P1/2b5 b - - 0 1


(Sorry I don't know how to post a diagram)

all you are missing is the [D] in front of the position

[Ron Murawski]

[D] 6KB/6P1/6b1/8/6P1/8/P2k2P1/2b5 b - - 0 1

It's probably wrong, but here is Horizon analysis:

22 +1.96 24.4M 0:32.07 Ba3 g5 Kd3 g3 Kd4 g4 Bc5 a4 Ke4 a5 Kf3 a6 Kxg4 a7 Bxa7 Kf8 Bc5+ Kg8 Be4 Kf7 Bd5+ Kf6 Bg8 Ke5
21 +1.92 18.1M 0:22.06 Ba3 g5 Kd3 g3 Kd4 g4 Bc5 a4 Ke4 a5 Kf3 a6 Kxg4 a7 Bxa7 Kf8 Bc5+ Kg8 Be4 Kf7 Bd5+ Kg6 Bg8 Kf6 Bd4+ Kg6 Kf4
20 +1.92 14.2M 0:17.06 Ba3 g5 Kd3 g4 Bc5 a4 Ke4 a5 Kf3 a6 Kxg4 a7 Bxa7 Kf8 Bc5+ Kg8 Be4 Kf7 Bd5+ Kg6 Bg8 Kf6 Bd4+ Kg6
19 +1.83 11.0M 0:13.18 Ba3 g5 Kd3 g4 Bc5 a4 Ke4 a5 Kf3 a6 Kxg4 a7 Bxa7 Kf8 Bc5+ Kg8 Be4 Kf7 Bd5+ Kg6 Bg8 Kf6
18 +1.83 8.7M 0:10.54 Ba3 g5 Kd3 g4 Bc5 a4 Ke4 a5 Kf3 a6 Kxg4 a7 Bxa7 Kf8 Bc5+ Kg8 Be4 Kf7 Bd5+ Kf6 Bg8
18 +1.83 6.8M 0:08.17 Ba3!
17 +0.72 6.3M 0:07.50 Ba3 g5 Kd3 g4 Be7 a4 Ke4 a5 Kf3 a6 Bc5 a7 Bxa7 Kf8 Bc5+ Kg8 Kf4

[F.Huber]

Fast enough?

ChestUCI Ver.5.1:
CPU: Celeron 400MHz
FEN: 6KB/6P1/6b1/8/6P1/8/P2k2P1/2b5 b - - (6+3)
Position-Analysis: C0/R0/K2/P4/X5 B:3/18
AutoTurbo-Search for Special-Mate [C1/R0/K0/P0/X0] in 20 ... (Hash=64MB)
AutoTurbo-Search for Special-Mate [C0/R0/K0/P0/X1] in 20 ... (Hash=64MB)
AutoTurbo-Search for Special-Mate [C0/R0/K0/P0/X2] in 20 ... (Hash=64MB)
17/20 00:10 848.194 110.298 +M17 1. ... Ba3
17/17 00:10 1.032.223 112.565 +M17 1. ... Ba3 2.g5 Kc3 3.g4 Kb4 4.Kf8 Kc4+ 5.Kg8 Kc5 6.Kf8 Kd5+ 7.Kg8 Kd6 8.Kf8 Ke6+ 9.Kg8 Be4 10.g6 Bxg6 11.g5 Bf5 12.g6 Kf6 13.Kh7 Bxg6+ 14.Kg8 Bc5 15.a3 Bf5 16.a4 Kg6 17.a5 Be6+
AutoTurbo-Search for Special-Mate [C0/R0/K0/P2/X2] in 17 ... (Hash=64MB)
17/17 00:19 848.194 109.585 +M17 1. ... Ba3
17/17 00:19 1.032.223 111.833 +M17 1. ... Ba3 2.g5 Kc3 3.g4 Kb4 4.Kf8 Kc4+ 5.Kg8 Kc5 6.Kf8 Kd5+ 7.Kg8 Kd6 8.Kf8 Ke6+ 9.Kg8 Be4 10.g6 Bxg6 11.g5 Bf5 12.g6 Kf6 13.Kh7 Bxg6+ 14.Kg8 Bc5 15.a3 Bf5 16.a4 Kg6 17.a5 Be6+
AutoTurbo-Search for Special-Mate [C0/R0/K3/P2/X2] in 17 ... (Hash=64MB)
17/17 00:29 848.194 108.742 +M17 1. ... Ba3
17/17 00:29 1.032.223 111.230 +M17 1. ... Ba3 2.g5 Kc3 3.g4 Kb4 4.Kf8 Kc4+ 5.Kg8 Kc5 6.Kf8 Kd5+ 7.Kg8 Kd6 8.Kf8 Ke6+ 9.Kg8 Be4 10.g6 Bxg6 11.g5 Bf5 12.g6 Kf6 13.Kh7 Bxg6+ 14.Kg8 Bc5 15.a3 Bf5 16.a4 Kg6 17.a5 Be6+
Mate in 17 found ! (1 Solution in 00:09)
17/17 00:29 1.032.223 111.230 +M17 1. ... Ba3 2.g5 Kc3 3.g4 Kb4 4.Kf8 Kc4+ 5.Kg8 Kc5 6.Kf8 Kd5+ 7.Kg8 Kd6 8.Kf8 Ke6+ 9.Kg8 Be4 10.g6 Bxg6 11.g5 Bf5 12.g6 Kf6 13.Kh7 Bxg6+ 14.Kg8 Bc5 15.a3 Bf5 16.a4 Kg6 17.a5 Be6+
Best move: Ba3, Value: +Mate in 17, Depth: 17/17, Time: 00:29,763, 1.032.223 Nodes, 111.230 N/sec

[Dr.Joy]

Superb..It even found a faster mate than the one I and my friend found , But ours is more beautiful:


[D] 6KB/6P1/6b1/8/6P1/8/P2k2P1/2b5 b - - 0 1


1... Ba3 2. g5 Kc3 3. g4 Kb4 4. Kf8 Kc4+ 5. Kg8 Kc5 6. Kf8 Kd5+ 7. Kg8 Kd6 8.Kf8 Kd7+ 9. Kg8 Be7 10. a4 Ke8 11. a5 Bxg5 12. a6 Ke7 13. a7 Be4 14. a8=Q Bxa8 15. Kh7 Be4+ 16. Kg8 Bh6 17. g5 Bg6 18. gxh6 Ke8 19. h7 Bf7#

But I am really curious to know if a "normal" engine (but not a mate solver like Chest) can find the solution using infinite analysis mode.

[Dr.Joy]

Thank you very much for you help Kenny

[Dr.Joy]

Franz..I tried ChestUCI on Rybka GUI and it is not giving the solution..it is just analyzing and analyzing...on which GUI do you run your amazing engine?

[F.Huber]

Hi Joy,

I´m always using Arena 1.1 for ChestUCI, but of course it should also run on the Rybka GUI (do you mean Aquarium or Rybka ChessBase?).

Just try the following settings:
SearchDepth = 20
SearchMode = AutoTurbo
SearchOrder = XPK

This will find the solution in 1-2 seconds on your (hopefully) faster computer than my old notebook.

[Dr.Joy]

Wow..thank you Franz...it worked like magic..I tried before asking you changing the search depth and the search mode and gained nothing...but changing the search order was the magical touch.but why it isn't the default setting?

[F.Huber]

...but changing the search order was the magical touch.but why it isn't the default setting?

Well, because it depends on the given position!
Sometimes it's better first trying to restrict the opponents king mobility (with KPX), but in this position it's quite obvious that white shouldn't be allowed to make too many moves, so restricting the white moves (with XPK) is the best choice.

It's all a matter of experience with mate problems and ChestUCI ...