Hard to find mate

Ajedrecista · Post by **Ajedrecista** » Mon Nov 28, 2022 8:26 pm

Code: Select all

2Q5/k7/8/8/8/8/1pp1p3/brrbK3 w - - 0 1
8/8/7k/4Q3/8/8/3p1pp1/3Kbrrb w - - 0 1
8/8/7k/8/4Q3/8/3p1pp1/3Kbrrb w - - 0 1
8/8/6k1/Q7/8/8/3p1pp1/3Kbrrb w - - 0 1
8/6p1/4Q3/6k1/8/8/3p1pp1/3Kbrrb w - - 0 1
Q7/8/8/7k/8/8/3p1pp1/3Kbrrb w - - 0 1
7k/8/5p2/8/8/8/P1Kp1pp1/4brrb w - - 0 1
8/8/8/8/4Q3/7k/3p1pp1/3Kbrrb w - - 0 1
8/8/4k3/8/8/8/3p1ppQ/3Kbrrb w - - 0 1
3Q4/8/8/8/k7/8/3p1pp1/3Kbrrb w - - 0 1
6k1/8/5Q2/8/8/8/3p1pp1/3Kbrrb w - - 0 1
8/8/7Q/4k3/8/8/3p1pp1/3Kbrrb w - - 0 1
6k1/8/8/8/8/8/P2p1pp1/3Kbrrb w - - 0 1
6k1/8/8/8/8/5p2/P2p1pp1/3Kbrrb w - - 0 1
6k1/8/8/8/8/3Q4/3p1pp1/3Kbrrb w - - 0 1
1k6/8/8/8/8/8/3p1ppP/3Kbrrb w - - 0 1

Good solving!

Regards from Spain.

Ajedrecista.

peter · Post by **peter** » Tue Nov 29, 2022 10:54 am

Ajedrecista wrote: ↑Mon Nov 28, 2022 8:26 pm K+Q (or K+P) against a lone king and a BRRB setup in the eighth rank (for example all in the queenside or all in the kingside) with pawns blocking rooks and bishops is a frequent arrangement:

https://pdb.dieschwalbe.de/P1101251
https://pdb.dieschwalbe.de/P1182321
https://pdb.dieschwalbe.de/P1182322
https://pdb.dieschwalbe.de/P1182438
https://pdb.dieschwalbe.de/P1193047
https://pdb.dieschwalbe.de/P1194083
https://pdb.dieschwalbe.de/P1197233
https://pdb.dieschwalbe.de/P1198388
https://pdb.dieschwalbe.de/P1199652
https://pdb.dieschwalbe.de/P1201204
https://pdb.dieschwalbe.de/P1226917
https://pdb.dieschwalbe.de/P1242244
https://pdb.dieschwalbe.de/P1269251
https://pdb.dieschwalbe.de/P1269252
https://pdb.dieschwalbe.de/P1270303
https://pdb.dieschwalbe.de/P1307131

Most of these problems were composed by Josef Halumbirek, who really exploited this pattern. Here are the FEN strings of these problems in the same order than posted before:
Code: Select all
2Q5/k7/8/8/8/8/1pp1p3/brrbK3 w - - 0 1
8/8/7k/4Q3/8/8/3p1pp1/3Kbrrb w - - 0 1
8/8/7k/8/4Q3/8/3p1pp1/3Kbrrb w - - 0 1
8/8/6k1/Q7/8/8/3p1pp1/3Kbrrb w - - 0 1
8/6p1/4Q3/6k1/8/8/3p1pp1/3Kbrrb w - - 0 1
Q7/8/8/7k/8/8/3p1pp1/3Kbrrb w - - 0 1
7k/8/5p2/8/8/8/P1Kp1pp1/4brrb w - - 0 1
8/8/8/8/4Q3/7k/3p1pp1/3Kbrrb w - - 0 1
8/8/4k3/8/8/8/3p1ppQ/3Kbrrb w - - 0 1
3Q4/8/8/8/k7/8/3p1pp1/3Kbrrb w - - 0 1
6k1/8/5Q2/8/8/8/3p1pp1/3Kbrrb w - - 0 1
8/8/7Q/4k3/8/8/3p1pp1/3Kbrrb w - - 0 1
6k1/8/8/8/8/8/P2p1pp1/3Kbrrb w - - 0 1
6k1/8/8/8/8/5p2/P2p1pp1/3Kbrrb w - - 0 1
6k1/8/8/8/8/3Q4/3p1pp1/3Kbrrb w - - 0 1
1k6/8/8/8/8/8/3p1ppP/3Kbrrb w - - 0 1

Nice collection, Jesus, thank you!

Don't understand the comments to the last one at the Schwalbe- site:

Cook: unlösbar 7. Db1+ Ka4! erfordert 39 Züge, jedoch ist die Lösung dann nicht mehr eindeutig.

Chest says:

Engine: ChestUCI Ver.5.2 (0 MB)
von Franz Huber
FEN: 1k6/8/8/8/8/8/3p1ppP/3Kbrrb w - - (2+8)
Stellungs-Analyse: C0/R0/K6/P1/X5 W:2/4
Suche nach 1. Spezial-Matt [C0/R0/K0/P1/X0] in 39 ... (Hash=2044MB)
Suche abgeschlossen ... (Zeit=0.37s)
39.02 0:00 +M39 1.h4
Berechnung abgebrochen !
Matt in 39 gefunden ! (1. Lösung in 00:00)
39/39 0:00 +M39 1.h4 Kb7 2.h5 Kb6 3.h6 Kb5 4.h7 Kb4 5.h8D Ka3 6.Da1+ Kb3 7.Db1+ Ka4 8.Db2 Ka5 9.Da1+ Kb4 10.Da2 Kb5 11.Da3 Kb6 12.Da4 Kb7 13.Da5 Kb8 14.Da6 1647
Bester Zug: h2-h4 Zeit: 0:05.813 min K/s: 1.647.206 Knoten: 606.172

Jouni · Post by **Jouni** » Tue Nov 29, 2022 4:31 pm

Analysis by The Huntsman 1:
...
1.h4 Kc7 2.h5 Kc6 3.h6 Kc5 4.h7 Kb4 5.h8Q Ka3 6.Qa1+ Kb3 7.Qb1+ Ka4 8.Qb2 Ka5 9.Qa1+ Kb4 10.Qa2 Kb5 11.Qa3 Kb6 12.Qa4 Kb7 13.Qa5 Kc6 14.Qb4 Kc7 15.Qb5 Kc8 16.Qb6 Kd7 17.Qc5 Ke6 18.Qc6+ Ke5 19.Qd7 Kf6 20.Qd6+ Kf7 21.Qe5 Kf8 22.Qe6 Kg7 23.Qf5 Kh8 24.Qg5 Kh7 25.Qe5 Kg8 26.Qf6 Kh7 27.Qf8 Kg6 28.Qe7 Kf5 29.Qd6 Kg5 30.Qe6 Kf4 31.Qd5 Kg4 32.Qe5 Kh4 33.Qe7+ Kg3 34.Qe4 Kh3 35.Qe6+ Kg3 36.Qf5 Kh4 37.Qg6 Kh3 38.Qg5 Kh2 39.Qh4#
+- (#39) Depth: 71/77 00:00:20 311mN

I haven't used Chest in years. 32b and single thread. OUTDATED. But I use Chest database

however.

F.Huber · Post by **F.Huber** » Tue Nov 29, 2022 5:17 pm

Jouni wrote: ↑Tue Nov 29, 2022 4:31 pm I haven't used Chest in years. 32b and single thread. OUTDATED.

Maybe, but still OUTSTANDING!

Ajedrecista · Post by **Ajedrecista** » Tue Nov 29, 2022 8:03 pm

Hello Peter:

peter wrote: ↑Tue Nov 29, 2022 10:54 am Nice collection, Jesus, thank you!

Don't understand the comments to the last one at the Schwalbe- site:
Cook: unlösbar 7. Db1+ Ka4! erfordert 39 Züge, jedoch ist die Lösung dann nicht mehr eindeutig.
Chest says:

Engine: ChestUCI Ver.5.2 (0 MB)
von Franz Huber
FEN: 1k6/8/8/8/8/8/3p1ppP/3Kbrrb w - - (2+8)
Stellungs-Analyse: C0/R0/K6/P1/X5 W:2/4
Suche nach 1. Spezial-Matt [C0/R0/K0/P1/X0] in 39 ... (Hash=2044MB)
Suche abgeschlossen ... (Zeit=0.37s)
39.02 0:00 +M39 1.h4
Berechnung abgebrochen !
Matt in 39 gefunden ! (1. Lösung in 00:00)
39/39 0:00 +M39 1.h4 Kb7 2.h5 Kb6 3.h6 Kb5 4.h7 Kb4 5.h8D Ka3 6.Da1+ Kb3 7.Db1+ Ka4 8.Db2 Ka5 9.Da1+ Kb4 10.Da2 Kb5 11.Da3 Kb6 12.Da4 Kb7 13.Da5 Kb8 14.Da6 1647
Bester Zug: h2-h4 Zeit: 0:05.813 min K/s: 1.647.206 Knoten: 606.172

As I understand, the cook is that the original stipulation was #38, but 7.- ..., Ka4 delays the checkmate one move more instead of the proposed 7.- ..., Ka3 by the composer.

Regarding '[...] the solution is no longer unique' (Google translator), I think it means that there is more than one solution with #39 (for example two or more equally good moves for either the winning side or the losing side). Something like that is said below in my post ('[...] all White's moves are uniquely forced in at least one full-length line. [...]').

The information provided by PDB is very good and therefore I found the issue of the magazine where the problem was originally published thanks to the excellent archive of the magazine: Problem 20 of the September 1978 issue of The Problemist.

https://www.theproblemist.org/mags.pl?type=tp

The Problemist — September 1978 (Vol. 10 No. 15)

The rightmost chessboard at the top of page 259.

The Problemist wrote:[...] In the remaining four problems, 17-20, we
show what we believe to be the longest accurate minimals with R, B, S and P—accurate in the sense that all White's moves are
uniquely forced in at least one full-length line. You will see that
we have composed three of them specially for this article, which
is perhaps one indication that the field of the direct-mate minimal
is by no means exhausted. [...]

The solution is in the right column of the next page:

The Problemist wrote:SOLUTIONS (from previous page)
[...] 20—5.h8Q Ka3!
6.Qa1+ Kb3 7.Qb1+ Ka3 8.Qc2 Kb4 9.Qa2 Kb5...13.Qa6 Kc7
14.Qb5 Kc8 15.Qb6 Kd7...21.Qe6 Kg7 22.Qf5 Kh8! 23.Qg5!
Kh7 24.Qe5! Kg8(Kh6) 25.Qf6(+)! Kh7 26.Qf8 Kg6 27.Qe7
Kf5...30.Qb4 Ke3...33.Qe4 Kh3 34.Qe6+! Kg3 35.Qf5 Kh4
36.Qg6 Kh3 37.Qg5 Kh2 38.Qh4≠.

------------

F.Huber wrote: ↑Tue Nov 29, 2022 5:17 pm
Jouni wrote: ↑Tue Nov 29, 2022 4:31 pm I haven't used Chest in years. 32b and single thread. OUTDATED.
Maybe, but still OUTSTANDING!

Regarding Chest: the programme and their programmers are true legends!

Regards from Spain.

Ajedrecista.

peter · Post by **peter** » Tue Nov 29, 2022 9:26 pm

Ajedrecista wrote: ↑Tue Nov 29, 2022 8:03 pm As I understand, the cook is that the original stipulation was #38, but 7.- ..., Ka4 delays the checkmate one move more instead of the proposed 7.- ..., Ka3 by the composer.

Regarding '[...] the solution is no longer unique' (Google translator), I think it means that there is more than one solution with #39 (for example two or more equally good moves for either the winning side or the losing side). Something like that is said below in my post ('[...] all White's moves are uniquely forced in at least one full-length line. [...]').

Thanks again for further investigation, for sure you will be right about the comments in Schwalbe, understood that in that way too, just wouldn't call duals at eighth move "cooked", but that's a term of different meanigs as well too of course, so nevermind, if it's a mate in x- puzzle, correct DTM also matters much of course, regards

Hard to find mate

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Re: Hard to find mate.

Re: Hard to find mate.