Difficult mate

Discussion of anything and everything relating to chess playing software and machines.

Moderator: Ras

Jouni
Posts: 3765
Joined: Wed Mar 08, 2006 8:15 pm
Full name: Jouni Uski

Difficult mate

Post by Jouni »

[fen]4R3/3p4/8/p1k5/8/p3p3/2P1K3/8 w - - 0 1[/fen]

Chessbase has main line as mate in 16. No it's not :) . Mate in 38?
Jouni
Top
User avatar
Ajedrecista
Posts: 2164
Joined: Wed Jul 13, 2011 9:04 pm
Location: Madrid, Spain.

Re: Difficult mate.

Post by Ajedrecista »

Hello Jouni:

The position is a study from 2007 that won the 3rd Special Price at Dvoretsky 60 Jubilee Tourney:

https://yacpdb.org/#574072

https://www.arves.org/arves/index.php/e ... 60-jt-2007

[pgn][Event "3 s.p Dvoretski 60 JT"]
[Site ""]
[Date "2007.12.07"]
[Round ""]
[White "L.Katsnelson"]
[Black ""]
[Result "1-0"]
[SetUp "1"]
[FEN "4R3/3p4/8/p1k5/8/p3p3/2P1K3/8 w - - 0 1"]
[PlyCount "31"]
[EventDate "2007"]
[SourceDate "2005.01.24"]

1. Re4 $1 (1. Rxe3 $2 Kb4 2. Kd2 a2 3. Re1 Ka3 $11) (1. Rh8 $2 Kc4 $11) 1...
Kb5 2. c4+ $1 Kb4 3. c5+ Kc3 4. Rxe3+ Kb2 5. Kd3 a2 6. Re2+ (6. Re1 $2 a1=Q 7.
Rxa1 Kxa1 $11) 6... Kb3 7. Re1 Kb2 8. Ra1 a4 9. Kd2 Kxa1 10. Kc1 a3 11. Kc2 d5
12. c6 d4 13. c7 d3+ 14. Kxd3 Kb2 15. c8=Q a1=Q 16. Qc2# 1-0[/pgn]

If you look into the PGN: 15.- ..., a1=Q is given and allows 16.- Qc2#, while other black moves delay the checkmate, so it is true that DTM > 16 moves because previous moves do not seem suboptimal. However, I think that this study was not composed as a DTM challenge (which you can try, of course) but to find critical only moves for white, like 1.- Re4; 2.- c4+; Kc1 after ..., Rxa1 (not Kc2?) and so on.

Summarizing: 'DTM challenge' versus 'find only moves to win' probable original intention. Kind of short answer: "Yes" with an "If", long answer: "No" with a "But" quote from The Simpsons S08 E08 'Hurricane Neddy' (1996).

Regards from Spain.

Ajedrecista.
Top
Jouni
Posts: 3765
Joined: Wed Mar 08, 2006 8:15 pm
Full name: Jouni Uski

Re: Difficult mate

Post by Jouni »

Analysis by The Huntsman 1:
...
1.Re4 Kb5 2.c4+ Kb4 3.c5+ Kb3 4.Rxe3+ Kb2 5.Kd3 a2 6.Re2+ Kb3 7.Re1 Kb2 8.Ra1 Kb3 9.Kd2 Kb2 10.Kd1 Kb3 11.Kc1 a4 12.Kd1 Kb2 13.Kd2 Kb3 14.Kc1 a3 15.Kd1 Kc3 16.Rxa2 Kb3 17.Rc2 a2 18.Rc1 Kb2 19.Ra1 Kb3 20.Kc1 Ka3 21.Kc2 Kb4 22.Rxa2 Kxc5 23.Kd3 Kd5 24.Ra5+ Kd6 25.Ke4 Kc6 26.Kd4 Kd6 27.Ra6+ Ke7 28.Kd5 Kf7 29.Kd6 Kg6 30.Ra5 Kg7 31.Kxd7 Kf6 32.Rd5 Kf7 33.Rd6 Kg8 34.Ke6 Kg7 35.Ke7 Kg8 36.Kf6 Kh8 37.Kg6
+- (#38) Depth: 71/75 00:05:53 5951mN
1.Re4 Kb5 2.c4+ Kb4 3.c5+ Kb3 4.Rxe3+ Kb2 5.Kd3 a2 6.Re2+ Kb3 7.Re1 Kb2 8.Ra1 Kb3 9.Kd2 Kb2 10.Kd1 Kb3 11.Kc1 a4 12.Kd2 Kb2 13.Kd1 Kb3 14.Kc1 a3 15.Kd1 Kc3 16.Rxa2 Kb3 17.Rc2 a2 18.Rc1 Kb2 19.Ra1 Kb3 20.Kc1 Ka3 21.Kc2 Kb4 22.Rxa2 Kxc5 23.Kd3 Kd5 24.Ra5+ Ke6 25.Kd4 Kf6 26.Rd5 d6 27.Rxd6+ Kf5 28.Rd5+ Ke6 29.Kc5 Ke7 30.Re5+ Kf7 31.Kd6 Kf6 32.Rb5 Kf7 33.Rf5+ Kg7 34.Ke7 Kg6 35.Rd5 Kg7 36.Rd6 Kg8 37.Kf6 Kh8 38.Kg6 Kg8 39.Rd8#
+- (#39) Depth: 72/78 00:06:21 6403mN
Jouni
Top
fishpov
Posts: 114
Joined: Sat Mar 07, 2015 6:05 pm

Re: Difficult mate

Post by fishpov »

Mat38 By Houdini 6.03 (very fast)
Analysis by Houdini 6.03 Pro x64-pext 1 Pro x64:
..
1.Re4 Kb5 2.c4+ Kb4 3.c5+ Kc3 4.Rxe3+ Kb2 5.Kd3 a2 6.Re2+ Kb3 7.Re1 Kb2 8.Ra1 Kb3 9.Ke2 Ka3 10.Kd1 Kb2 11.Kd2 Kb3 12.Kc1 a4 13.Kd2 Kb2 14.Kd1 Kb3 15.Kc1 a3 16.Kd1 Kc3 17.Rxa2 Kb3 18.Rc2 a2 19.Rc1 Kb2 20.Ra1
+- (#40) Depth: 33/75 00:00:09 169MN, tb=1945933
1.Re4 Kb5 2.c4+ Kb4 3.c5+ Kc3 4.Rxe3+ Kb2 5.Kd3 a2 6.Re2+ Kb3 7.Re1 Kb2 8.Ra1 Kb3 9.Ke2 Ka3 10.Kd1 Kb2 11.Kd2 Kb3 12.Kc1 a4 13.Kd2 Kb2 14.Kd1 Kb3 15.Kc1 a3 16.Kd1 Kc3 17.Rxa2 Kb3 18.Rc2 a2 19.Rc1 Kb2 20.Ra1
+- (#40) Depth: 33/75 00:00:09 169MN, tb=1946227
1.Re4 Kb5 2.c4+ Kb4 3.c5+ Kc3 4.Rxe3+ Kb2 5.Kd3 a2 6.Re2+ Kb1 7.Re1+ Kb2 8.Ra1 Kb3 9.Ke2 Ka3 10.Kd1 Kb2 11.Kd2 Kb3 12.Kc1 a4 13.Kd2 Kb2 14.Kd1 Kb3 15.Kc1 a3 16.Kd1 Kc3 17.Rxa2 Kb3 18.Rc2 a2 19.Rc1 Kb2 20.Ra1 Kb3 21.Kc1
+- (#39) Depth: 34/75 00:00:09 173MN, tb=1993518
1.Re4 Kb5 2.c4+ Kb4 3.c5+ Kc3 4.Rxe3+ Kb2 5.Kd3 a2 6.Re2+ Kb1 7.Re1+ Kb2 8.Ra1 Kb3 9.Ke2 Ka3 10.Kd1 Kb2 11.Kd2 Kb3 12.Kc1 a4 13.Kd2 Kb2 14.Kd1 Kb3 15.Kc1 a3 16.Kd1 Kc3 17.Rxa2 Kb3 18.Rc2 a2 19.Rc1 Kb2 20.Ra1 Kb3 21.Kc1
+- (#39) Depth: 34/75 00:00:09 174MN, tb=2008300
1.Re4 Kb5 2.c4+ Kb4 3.c5+ Kc3 4.Rxe3+ Kb2 5.Kd3 a2 6.Re2+ Kb3 7.Re1 Kb2 8.Ra1 Kb3 9.Kd2 Kb2 10.Kd1 Kb3 11.Kc1 a4 12.Kd2 Kb2 13.Kd1 Kb3 14.Kc1 a3 15.Kd1 Kc3 16.Rxa2 Kb3 17.Rc2 a2 18.Rc1 Kb2 19.Ra1 Kb3 20.Kc1
+- (#38) Depth: 35/75 00:00:10 179MN, tb=2108333
..
1.Re4 Kb5 2.c4+ Kb4 3.c5+ Kc3 4.Rxe3+ Kb2 5.Kd3 a2 6.Re2+ Kb3 7.Re1 Kb2 8.Ra1 Kb3 9.Kd2 Kb2 10.Kd1 Kb3 11.Kc1 a4 12.Kd2 Kb2 13.Kd1 Kb3 14.Kc1 a3 15.Kd1 Kc3 16.Rxa2 Kb3 17.Rc2 a2 18.Rc1 Kb2 19.Ra1 Kb3 20.Kc1 Ka3 21.Kc2 Kb4 22.Rxa2
+- (#38) Depth: 63/94 02:23:52 58098MN, tb=402173997
Top
Jouni
Posts: 3765
Joined: Wed Mar 08, 2006 8:15 pm
Full name: Jouni Uski

Re: Difficult mate

Post by Jouni »

Thanks! 38 move line is very similar to Huntsman's line.
Jouni
Top
jhellis3
Posts: 548
Joined: Sat Aug 17, 2013 12:36 am

Re: Difficult mate

Post by jhellis3 »

Let Crystal dev run a while and it bounced between 39 & 38, eventually settling on 38 with a couple of different lines.
Top
Vinvin
Posts: 5310
Joined: Thu Mar 09, 2006 9:40 am
Full name: Vincent Lejeune

Re: Difficult mate

Post by Vinvin »

On 3 runs, regular Stockfish, on my AMD 5950x 16 cores, gives mate in 38 in : 1m27s, 2m38s and 49s. Average : 1m38s

FEN: 4R3/3p4/8/p1k5/8/p3p3/2P1K3/8 w - - 0 1

Code: Select all

Stockfish_22090705_x64_avx2:
Found 513 tablebases
NNUE evaluation using nn-ad9b42354671.nnue enabled
...
 80/41	00:02	 67.166k	30.995k	+152,49	1.Re4 Kb5 2.c4+ Kb4 3.c5+ Kc3 4.Rxe3+ Kb2 5.Kd3 a2 6.Re2+ Kb3 7.Re1 Kb2 8.Ra1 Kb3 9.Kd2 Kb2 10.Kd1 Kb3 11.Kc1 a4 12.Kd2 Kb2 13.Kd1 Kb3 14.Kc1 a3 15.Kd1 Kb2 16.Kd2 Kb3 17.Kc1 Kc3 18.Rxa2 Kb3 19.c6 dxc6
 81/41	00:02	 96.623k	33.796k	+152,49	1.Re4 Kb5 2.c4+ Kb4 3.c5+ Kc3 4.Rxe3+ Kb2 5.Kd3 a2 6.Re2+ Kb3 7.Re1 Kb2 8.Ra1 Kb3 9.Kd2 Kb2 10.Kd1 Kb3 11.Kc1 a4 12.Kd2 Kb2 13.Kd1 Kb3 14.Kc1 a3 15.Kd1 Kb2 16.Kd2 Kb3 17.Kc1 Kc3 18.Rxa2 Kb3 19.c6 dxc6
 82/93	00:58	 2.639.754k	45.042k	+M39	1.Re4 Kb5 2.c4+ Kb4 3.c5+ Kc3 4.Rxe3+ Kb2 5.Kd3 a2 6.Re2+ Kb3 7.Re1 Kb2 8.Ra1 Kb3 9.Kd2 Kb2 10.Kd1 Kb3 11.Kc1 a4 12.Kd2 Kb2 13.Kd1 Kb3 14.Kc1 a3 15.Kd1 Kc3 16.Rxa2 Kb3 17.Rc2 a2 18.Rc1 Kb2 19.Ra1 Kb3 20.Kc1 Kc4 21.Rxa2 Kxc5 22.Rd2 Kc6 23.Kc2 d6 24.Rd1 Kc5 25.Kc3 d5 26.Re1 d4+ 27.Kd3 Kd5 28.Re4 Kd6 29.Kxd4 Kc6 30.Re6+ Kd7 31.Kd5 Kc7 32.Re5 Kd7 33.Kc5 Kc7 34.Rd5 Kb7 35.Rd7+ Kc8 36.Kc6 Kb8 37.Rd8+ Ka7 38.Rg8 Ka6 39.Ra8+
 83/82	01:27	 4.079.358k	46.465k	+M38	1.Re4 Kb5 2.c4+ Kb4 3.c5+ Kc3 4.Rxe3+ Kb2 5.Kd3 a2 6.Re2+ Kb3 7.Re1 Kb2 8.Ra1 Kb3 9.Kd2 Kb2 10.Kd1 Kb3 11.Kc1 a4 12.Kd1 Kb2 13.Kd2 Kb3 14.Kc1 a3 15.Kd1 Kc3 16.Rxa2 Kb3 17.Rc2 a2 18.Rc1 Kb4 19.Ra1 Kb3 20.Kc1 Kb4 21.Kc2 Kxc5 22.Kd3 Kd6 23.Ke4 Kc5 24.Rxa2 Kd6 25.Rd2+ Ke6 26.Rd5 Kf6 27.Rxd7 Ke6 28.Rd5 Kf6 29.Rd6+ Ke7 30.Ke5 Kf7 31.Kf5 Ke7 32.Rd1 Kf7 33.Rd7+ Ke8 34.Ke6 Kf8 35.Kf6 Kg8 36.Rd8+ Kh7 37.Ra8 Kh6 38.Rh8+
 84/78	01:38	 4.622.592k	46.997k	+M38	1.Re4 Kb5 2.c4+ Kb4 3.c5+ Kc3 4.Rxe3+ Kb2 5.Kd3 a2 6.Re2+ Kb3 7.Re1 Kb2 8.Ra1 Kb3 9.Kd2 Kb2 10.Kd1 Kb3 11.Kc1 a4 12.Kd1 Kb2 13.Kd2 Kb3 14.Kc1 a3 15.Kd1 Kc3 16.Rxa2 Kb3 17.Rc2 a2 18.Rc1 Kb4 19.Ra1 Kb3 20.Kc1 Kc4 21.Kc2 Kd4 22.Rxa2 Kxc5 23.Kd3 Kd5 24.Ra5+ Ke6 25.Ke4 Kd6 26.Rh5 Kc6 27.Kd4 d6 28.Ke4 d5+ 29.Rxd5 Kc7 30.Kd4 Kb6 31.Rc5 Kb7 32.Kd5 Kb6 33.Kd6 Kb7 34.Rb5+ Ka6 35.Kc6 Ka7 36.Ra5+ Kb8 37.Ra1 Kc8 38.Ra8+

Code: Select all

Stockfish_22090705_x64_avx2:
Found 513 tablebases
NNUE evaluation using nn-ad9b42354671.nnue enabled
...
 79/41	00:04	 140.005k	29.568k	+152,49	1.Re4 Kb5 2.c4+ Kb4 3.c5+ Kc3 4.Rxe3+ Kb2 5.Kd3 a2 6.Re2+ Kb3 7.Re1 Kb2 8.Ra1 Kb3 9.Kd2 Kb2 10.Kd1 Kb3 11.Kc1 a4 12.Kd2 Kb2 13.Kd1 Kb3 14.Kc1 a3 15.Kd1 Kb2 16.Kd2 Kb3 17.Kc1 Kb4 18.Rxa2 Kb3 19.c6 dxc6
 80/41	00:15	 487.892k	30.541k	+152,49	1.Re4 Kb5 2.c4+ Kb4 3.c5+ Kc3 4.Rxe3+ Kb2 5.Kd3 a2 6.Re2+ Kb3 7.Re1 Kb2 8.Ra1 Kb3 9.Kd2 Kb2 10.Kd1 Kb3 11.Kc1 a4 12.Kd2 Kb2 13.Kd1 Kb3 14.Kc1 a3 15.Kd1 Kb2 16.Kd2 Kb3 17.Kc1 Kb4 18.Rxa2 Kb3 19.c6 dxc6
 81/102	01:16	 3.130.906k	40.966k	+M39	1.Re4 Kb5 2.c4+ Kb4 3.c5+ Kc3 4.Rxe3+ Kb2 5.Kd3 a2 6.Re2+ Kb3 7.Re1 Kb2 8.Ra1 Kb3 9.Kd2 Kb2 10.Kd1 Kb3 11.Kc1 a4 12.Kd2 Kb2 13.Kd1 Kb3 14.Kc1 a3 15.Kd1 Kc3 16.Rxa2 Kb3 17.Rc2 a2 18.Rc1 Kb2 19.Ra1 Kb3 20.Kc1 Kb4 21.Rxa2 Kxc5 22.Kc2 Kc4 23.Ra4+ Kd5 24.Kd3 Kd6 25.Ra5 Ke6 26.Ke4 Kd6 27.Rh5 Kc6 28.Kd4 Kb6 29.Rd5 Kc6 30.Ke5 Kc7 31.Rc5+ Kb7 32.Kd6 Kb6 33.Rf5 Kb7 34.Kxd7 Kb6 35.Rd5 Kb7 36.Rd6 Kb8 37.Kc6 Ka7 38.Rd8 Ka6 39.Ra8+
 82/76	02:38	 6.749.558k	42.558k	+M38	1.Re4 Kb5 2.c4+ Kb4 3.c5+ Kc3 4.Rxe3+ Kb2 5.Kd3 a2 6.Re2+ Kb3 7.Re1 Kb2 8.Ra1 Kb3 9.Kd2 Kb2 10.Kd1 Kb3 11.Kc1 a4 12.Kd2 Kb2 13.Kd1 Kb3 14.Kc1 a3 15.Kd1 Kc3 16.Rxa2 Kb3 17.Rc2 a2 18.Rc1 Kb2 19.Ra1 Kb3 20.Kc1 Kb4 21.Kc2 Kb5 22.Rxa2 Kxc5 23.Ra7 Kd6 24.Kd3 Ke6 25.Kd4 d6 26.Ra6 Kf6 27.Rxd6+ Kf5 28.Rd5+ Ke6 29.Ke4 Kf6 30.Re5 Kg6 31.Rf5 Kh6 32.Kf4 Kg6 33.Kg4 Kh7 34.Kg5 Kg7 35.Rf2 Kh7 36.Kf6 Kh8 37.Kf7 Kh7 38.Rh2+
 83/76	02:39	 6.788.261k	42.572k	+M38	1.Re4 Kb5 2.c4+ Kb4 3.c5+ Kc3 4.Rxe3+ Kb2 5.Kd3 a2 6.Re2+ Kb3 7.Re1 Kb2 8.Ra1 Kb3 9.Kd2 Kb2 10.Kd1 Kb3 11.Kc1 a4 12.Kd2 Kb2 13.Kd1 Kb3 14.Kc1 a3 15.Kd1 Kc3 16.Rxa2 Kb3 17.Rc2 a2 18.Rc1 Kb2 19.Ra1 Kb3 20.Kc1 Kc4 21.Kc2 Kd5 22.Rxa2 Kxc5 23.Kd3 Kd6 24.Kd4 Ke6 25.Ra6+ Kf5 26.Rd6 Kf4 27.Rxd7 Kf5 28.Rd5+ Ke6 29.Ke4 Kf6 30.Re5 Kg6 31.Rf5 Kh6 32.Kf4 Kg6 33.Kg4 Kh7 34.Kg5 Kg7 35.Rf2 Kh7 36.Kf6 Kh8 37.Kf7 Kh7 38.Rh2+

Code: Select all

Stockfish_22090705_x64_avx2:
Found 513 tablebases
NNUE evaluation using nn-ad9b42354671.nnue enabled
...
 87/76	00:04	 169.635k	36.941k	+152,49	1.Re4 Kb5 2.c4+ Ka4 3.c5+ Kb3 4.Rxe3+ Kb2 5.Kd3 a2 6.Re2+ Ka3 7.Re1 Kb2 8.Ra1 Kb3 9.Kd2 Kb2 10.Kd1 Kb3 11.Kc1 a4 12.Kd1 Kb2 13.Kd2 Kb3 14.Kc1 a3 15.Kd1 Kb2 16.Kd2 Kb3 17.Kc1 Kc3 18.Rxa2 Kb3 19.c6 dxc6
 88/86	00:49	 2.487.303k	50.255k	+M38	1.Re4 Kb5 2.c4+ Ka4 3.c5+ Kb3 4.Rxe3+ Kb2 5.Kd3 a2 6.Re2+ Ka3 7.Re1 Kb2 8.Ra1 Kb3 9.Kd2 Kb2 10.Kd1 Kb3 11.Kc1 a4 12.Kd2 Kb2 13.Kd1 Kb3 14.Kc1 a3 15.Kd1 Kc3 16.Rxa2 Kb3 17.Rc2 a2 18.Rc1 Kb2 19.Ra1 Kb3 20.Kc1 Kc4 21.Kc2 Kxc5 22.Kd3 Kd5 23.Rxa2 Kc5 24.Ra5+ Kd6 25.Ke4 Kc6 26.Kd4 Kd6 27.Ra6+ Ke7 28.Ke5 Kf7 29.Kd6 Kf6 30.Ra5 Kg6 31.Kxd7 Kf6 32.Rd5 Kg7 33.Ke6 Kg6 34.Ke7 Kg7 35.Rd6 Kh8 36.Kf7 Kh7 37.Ra6 Kh8 38.Rh6+
Top

Return to “Computer Chess Club: General Topics”