Million Mate Madness

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Dann Corbit
Posts: 12538
Joined: Wed Mar 08, 2006 8:57 pm
Location: Redmond, WA USA

Million Mate Madness

Post by Dann Corbit »

There are more than one million verified checkmates in this file:
https://www.dropbox.com/s/2gd72g3xrr36n ... at.7z?dl=0

Specifically, there are 1,112,569 checkmates between mate in 1 and mate in 8.

Each checkmate has been verified by Chest319 (so brute force, no shortcuts).

If you like solving chess puzzles or are otherwise deranged, you might enjoy it.

The file contains the positions which are annotated with the solutions.

Here are the first ten positions from the file:
rrrr3k/5ppp/8/4R3/4R3/4R3/4RPPP/4R2K w - - acn 244855; acs 0; bm Re8+; ce 32758; dm 5; pv Re8+ Rxe8 Rxe8+ Rxe8 Rxe8+ Rxe8 Rxe8+ Rxe8 Rxe8#;
rrrr1k2/7R/8/8/3R4/3R4/3R4/3RK3 w - - acn 709; acs 0; bm Rf2+ Rf3+ Rf4+; ce 32762; dm 3; pv Rf4+ Kg8 Rg3+ Kxh7 Rh4#;
rrqnKQ2/ppp1pp1k/4p1pp/3b4/8/P1P4P/1P1PPPP1/2B5 b - - acn 25; acs 0; bm Nc6+; ce 32764; dm 2; pv Nc6+ Kxf7 e5#;
rrqN4/8/n1p2Q2/2p1R3/Kppk4/2pb4/2p5/2n1N3 w - - acn 2; acs 0; bm Nf3# Qd6#; ce 32766; dm 1; pv Nf3#;
rrqN4/8/n1p2Q2/2p1R3/Kppk4/2pb4/2p5/2n1N3 b - - acn 1; acs 0; bm Nc7#; ce 32766; dm 1; pv Nc7#;
rrq4k/6p1/2N4p/8/6R1/5n2/4K3/1B6 b - - acn 2939550; acs 5; bm Qxg4 Rb2+ Rxb1; ce 32756; dm 6; pv Rb2+ Bc2 Rxc2+ Ke3 Ra3+ Kf4 Qc7+ Ke4 Rc4+ Nd4 Qe5#;
rrq2QK1/1b1p4/1N1R4/bk6/8/p1p5/8/n7 b - - acn 85; acs 0; bm Qxf8+; ce 32762; dm 3; pv Qxf8+ Kh7 Be4+ Rg6 Qh8#;
rrq2N2/PPkPP1P1/K7/8/8/2n5/ppp1ppp1/1RnBbbN1 b - - acn 51; acs 0; bm Qxb7+ Rxa7+ a1=Q+ a1=R+; ce 32764; dm 2; pv a1=Q+ Rxa1 bxa1=Q#;
rrq1k3/3nPp2/2ppbp2/8/8/4K3/8/8 b - - acn 421; acs 0; bm Ra2 Rb2; ce 32762; dm 3; pv Rb2 Kf3 Ra3+ Kf4 Rb4#;
rrq1k3/3nPp2/2ppbp2/8/3K4/8/8/8 b - - acn 6; acs 0; bm Ra3 Rb3; ce 32764; dm 2; pv Rb3 Ke4 Ra4#;


From time to time, I will add to the collection.
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Matthias Gemuh
Posts: 3245
Joined: Thu Mar 09, 2006 9:10 am

Re: Million Mate Madness

Post by Matthias Gemuh »

Thanks a lot, Dann.
My engine was quite strong till I added knowledge to it.
http://www.chess.hylogic.de
Frank Quisinsky
Posts: 6808
Joined: Wed Nov 18, 2009 7:16 pm
Location: Gutweiler, Germany
Full name: Frank Quisinsky

Re: Million Mate Madness

Post by Frank Quisinsky »

Hi Dann,

do you checked all the mates really with Chest 319 only or do you try out other engines too? If so, do you prefers engine for the mate search 1-8 moves? Which engines you prefers?

Many chess engine can't produce the correct way to mate (Mate in 8, one move later ... Mate in 6, one move later Mate in 4 for an example).

WOW, have a lot of thanks!

I know that ChessAssistant produced such CDs with mate positions for "mate Training". But easy mates only you can find in the collection by Convekta and not such a big database you public now.

Thanks again!
Good idea!

Maybe such a work should be sorted ...
Database with Mate in 1, other database with Mate in 2 ... and more as Mate in 8 later.

Very, very nice idea you have here!

Best
Frank
Dann Corbit
Posts: 12538
Joined: Wed Mar 08, 2006 8:57 pm
Location: Redmond, WA USA

Re: Million Mate Madness

Post by Dann Corbit »

The mates were initially found with various different chess engines, along with Chest for some of them.

Sometimes, the engines get a wrong solution (both too many moves to find the mate and even too few moves).

So I validated them with Chest.

I have a lot more deeper checkmates, but it takes a long time to prove them with Chest.

Since the mate puzzles have the depth to mate stored in them, it is easy to group them by depth.

I have them stored in a database, so I can query on them by any criteria I choose.
Frank Quisinsky
Posts: 6808
Joined: Wed Nov 18, 2009 7:16 pm
Location: Gutweiler, Germany
Full name: Frank Quisinsky

Re: Important for programmers too ...

Post by Frank Quisinsky »

OK!

You know that this material could be nice for each programmer. Can be sorted with tools ...

Example:
3-10 pieces on board
10-16 pieces on board

After this one programmer can use your work and have a chance for a good test with the own engine and the correct way to mate ... with different quantity of pieces on the board.

Important work because it's one of the main problems today. Most programmer using for own eng-eng matches resign=on and can't see the problems with time loses before mate or the wrong way to mate.

Chest is really a great work!

Best
Frank
rabbits23
Posts: 144
Joined: Fri Sep 12, 2014 4:57 am
Location: Randwick Australia

Re: Million Mate Madness

Post by rabbits23 »

Good one Dann
Allan
Ferdy
Posts: 4833
Joined: Sun Aug 10, 2008 3:15 pm
Location: Philippines

Re: Million Mate Madness

Post by Ferdy »

Thank you for sharing.
It would be great also if you can supply the bestmove in long algebraic notation (LAN) via comment.
From,
rrrr3k/5ppp/8/4R3/4R3/4R3/4RPPP/4R2K w - - acn 244855; acs 0; bm Re8+; ce 32758; dm 5; pv Re8+ Rxe8 Rxe8+ Rxe8 Rxe8+ Rxe8 Rxe8+ Rxe8 Rxe8#;
To,
rrrr3k/5ppp/8/4R3/4R3/4R3/4RPPP/4R2K w - - acn 244855; acs 0; bm Re8+; ce 32758; dm 5; pv Re8+ Rxe8 Rxe8+ Rxe8 Rxe8+ Rxe8 Rxe8+ Rxe8 Rxe8#; c0 "e5e1"
It would be easy to create a script and run some engines by looking at its bestmove output which uci engines (for example) will send in LAN.

Your epd has a dm info, and some uci engines are able to send "score mate 5" which is one the standards in uci for sending huge score, the script can also compare distance to mate in this case.

Another method of evaluating solution is by looking at the output of the engine, again it would be good also if you can supply via Opcode v0 for example the pv but in LAN, like the following.
...; v0 "e5e8 d8e8 e4e8 c8e8 e3e8 b8e8 e2e8 a8e8 e1e8"
The script will compare the uci engine output with the v0 value.

Example uci engine analysis session.

Code: Select all

position fen rrrr3k/5ppp/8/4R3/4R3/4R3/4RPPP/4R2K w - -
go movetime 10000
info depth 1 seldepth 5 score cp 617 time 0 nodes 47 nps 0 tbhits 0 pv e5e7
info depth 2 seldepth 9 score mate 5 time 0 nodes 193 nps 0 tbhits 0 pv e5e8
info depth 2 seldepth 9 score mate 5 time 23 nodes 299 nps 13000 tbhits 0 pv e5e
8 d8e8 e4e8 c8e8 e3e8 b8e8 e2e8 a8e8 e1e8

[...]

info depth 16 seldepth 27 score mate 5 time 8663 nodes 7017675 nps 810074 tbhits
 0 pv e5e8 d8e8 e4e8 c8e8 e3e8 b8e8 e2e8 a8e8 e1e8
info nodes 7328768 nps 812051
bestmove e5e8
Maarten Claessens
Posts: 106
Joined: Mon May 12, 2014 10:08 am
Location: Near Nijmegen

Re: Million Mate Madness

Post by Maarten Claessens »

Dann Corbit wrote:There are more than one million verified checkmates in this file:
https://www.dropbox.com/s/2gd72g3xrr36n ... at.7z?dl=0

Specifically, there are 1,112,569 checkmates between mate in 1 and mate in 8.
...
Actually there are also 22 mate in 9 positions, of wich the hardest one is:

Code: Select all

1qbqkbq1/QBRNBNQ1/1QnQpQn1/1q1RQ1p1/3rn3/2Q2Q2/Q6K/1r4r1 w - - acn 1109146493; acs 1726; bm Qdxe6 Qxb1; ce 32750; dm 9; pv Qdxe6 Rh1+ Qxh1 Rd2+ Qcxd2 Rxh1+ Kxh1 Nf2+ Qbxf2 Qh8+ Qxh8 Qxd5+ Qaxd5 Qxd7 Nd6+ Qxd6 Qff7#;
It takes WaDuuttie (1 CPU and 1Gb hash) 42,939,278,422 nodes and over 4 and a half hour to find the solution:

Code: Select all

FEN: 1qbqkbq1/QBRNBNQ1/1QnQpQn1/1q1RQ1p1/3rn3/2Q2Q2/Q6K/1r4r1 w - - 0 1 

WaDuuttie_com:
   1	00:00	     710,289	1,578,420	+47.78	d7b8
   2	00:08	  16,662,569	2,005,122	+46.72	d7b8 g1g2 a2g2
   3	00:10	  20,568,765	2,030,480	+46.78	d7b8 b5b2 a2b2 b1b2 h2g1
   4	00:14	  32,648,398	2,204,483	+50.48	d7b8 g1h1 f3h1 d4d2 d5d2 b5e5 f6e5 b1h1 h2h1 e4g3 e5g3
   5	00:16	  37,815,836	2,240,274	+50.72	d7b8 g1h1 f3h1 b1h1 h2h1 e4g3 h1g1 g3e2 e5e2
   6	00:21	  51,180,472	2,315,858	+51.20	d7b8!
   6	00:45	 108,268,355	2,380,047	+50.24	d7b8?
   6	00:50	 120,288,656	2,373,025	+51.86	d7b8 g1h1 f3h1 b1h1 h2h1 c8d7 e7d8 e4f6 g7g8 d4h4 h1g1
   7	00:53	 126,540,122	2,386,198	+52.34	d7b8!
   7	01:04	 155,069,021	2,405,289	+53.34	d7b8!
   7	01:15	 182,095,831	2,424,065	+56.26	d7b8 d4d2 a2d2 g1h1 f3h1 b1h1 h2h1 c8d7 f7d8 e4f6 g7g8 b5f1 h1h2
   8	01:21	 199,234,882	2,425,552	+56.74	d7b8!
   8	01:32	 225,674,837	2,438,936	+57.74	d7b8!
   8	01:50	 268,503,585	2,436,069	+60.74	d7b8!
   8	02:15	 329,364,004	2,431,987	+63.58	d7b8 g1h1 f3h1 b5b2 a2b2 b1b2 b6b2 c8d7 c7d7 d8a5 d5d4
   9	02:27	 358,266,972	2,426,461	+64.06	d7b8!
   9	02:39	 385,624,191	2,424,089	+M247	d7b8!
   9	03:01	 441,406,831	2,425,845	+M97	d7b8!
   9	03:29	 501,459,870	2,396,233	+M261	d7b8 g1h1 f3h1 b1h1 h2h1 e4f2 a2f2 b5f1 f2f1 d4h4 h1g1 h4g4 e5g3 g4g3 d6g3 d8e7 c7c8 e7d8
  10	08:56	1,135,377,778	2,117,096	+M490	d7b8?
  10	09:20	1,189,376,689	2,121,159	+M237	d7b8!
  10	09:36	1,225,331,053	2,124,213	+M37	d7b8!
  10	09:42	1,237,647,560	2,126,359	+M11	d7b8 g1h1 f3h1 b1h1 h2h1 e4f2 a2f2 b5f1 f2f1 d4h4 h1g1 h4g4 e5g3 g4g3 d6g3 d8e7 c7c8 c6d8 c8d8 e7d8 d5d8
  11	13:39	1,752,851,071	2,138,562	+M11	d7b8 g1h1 f3h1 b1h1 h2h1 e4f2 a2f2 b5f1 f2f1 d4h4 h1g1 h4g4 e5g3 g4g3 d6g3 d8e7 c7c8 c6d8 c8d8 e7d8 d5d8
  12	30:26	4,034,848,291	2,209,108	+M11	d7b8 g1h1 f3h1 b1h1 h2h1 e4f2 a2f2 b5f1 f2f1 d4h4 h1g1 h4g4 e5g3 g4g3 d6g3 d8e7 c7c8 c6d8 c8d8 e7d8 d5d8
  13	1:38:41	13,806,841,894	2,368,415	+M11	d7b8 g1h1 f3h1 b1h1 h2h1 e4f2 a2f2 b5f1 f2f1 d4h4 h1g1 h4g4 e5g3 g4g3 d6g3 d8e7 c7c8 c6d8 c8d8 e7d8 d5d8
  14	4:34:16	42,939,278,422	2,623,907	+M9	d6e6 g1h1 f3h1 b1h1 h2h1 d4d1 d5d1 g8h7 g7h7 e4f2 a2f2 b5f1 d1f1 d8c7 f7d6 c7d6 h7g6
  15	4:44:59	44,694,705,228	2,627,939	+M9	d6e6 g1h1 f3h1 b1h1 h2h1 d4d1 d5d1 g8h7 g7h7 e4f2 a2f2 b5f1 d1f1 d8c7 f7d6 c7d6 h7g6
I tried a few other engines, but even Stockfish seems to choke on this one!
Nothing is unstable (Lawrence Krauss)
zullil
Posts: 6442
Joined: Tue Jan 09, 2007 12:31 am
Location: PA USA
Full name: Louis Zulli

Re: Million Mate Madness

Post by zullil »

Maarten Claessens wrote: [D]1qbqkbq1/QBRNBNQ1/1QnQpQn1/1q1RQ1p1/3rn3/2Q2Q2/Q6K/1r4r1 w - -
It takes WaDuuttie (1 CPU and 1Gb hash) 42,939,278,422 nodes and over 4 and a half hour to find the solution:

I tried a few other engines, but even Stockfish seems to choke on this one!
Stockfish 6 seems fine---with parallel search!

Code: Select all

info depth 20 seldepth 24 multipv 1 score mate 9 nodes 3623820286 nps 22279044 tbhits 0 time 162656 pv d6e6 g1h1 f3h1 b1h1 h2h1 e4f2 f6f2 d4h4 c3h3 h4h3 e6h3 b5f1 f2f1 d8d7 h3d7 c8d7 f7d6
User avatar
Ajedrecista
Posts: 1968
Joined: Wed Jul 13, 2011 9:04 pm
Location: Madrid, Spain.

Re: Million Mate Madness.

Post by Ajedrecista »

Hello Maarten:

Once I moved 1.- Qdxe6, Chest UCI 5.2 finds multiple solutions:

Code: Select all

FEN: 1qbqkbq1/QBRNBNQ1/1Qn1QQn1/1q1RQ1p1/3rn3/2Q2Q2/Q6K/1r4r1 b - - 0 1 

ChestUCI_52:
FEN: 1qbqkbq1/QBRNBNQ1/1Qn1QQn1/1q1RQ1p1/3rn3/2Q2Q2/Q6K/1r4r1 b - -   (16+14)
Stellungs-Analyse:  S:13/69
Suche nach Matt in -9 ...  (Hash=512MB)
Suche abgeschlossen ...  (Zeit=47.50s)
Matt in -8 gefunden !  (112 Lösungen in 00:47)
  1/8	00:48	  14.425.096	303.686	-M1	Qg8xf7 Qe6xf7+
  1/8	00:48	  14.425.096	303.686	-M1	Qg8xf7 Qf6xf7+
  1/8	00:48	  14.425.096	303.686	-M1	Qg8xf7 Qg7xf7+
  1/8	00:48	  14.425.096	303.686	-M1	Ne4g3 Nf7d6+
  1/8	00:48	  14.425.096	303.686	-M1	Ne4f2 Nf7d6+
  1/8	00:48	  14.425.096	303.686	-M1	Ne4xf6 Nd7xf6+
  1/8	00:48	  14.425.096	303.686	-M1	Ne4xf6 Nf7d6+
  1/8	00:48	  14.425.096	303.686	-M1	Ne4d2 Nf7d6+
  1/8	00:48	  14.425.096	303.686	-M1	Ne4d6 Nf7xd6+
  1/8	00:48	  14.425.096	303.686	-M1	Ne4xc3 Nf7d6+
  1/8	00:48	  14.425.096	303.686	-M1	Ne4c5 Nf7d6+
  2/8	00:48	  14.425.096	303.686	-M2	Bf8xe7 Qg7xg8+ Ng6f8 Qg8xf8+
  3/8	00:48	  14.425.096	303.686	-M3	Qb8xc7 Nf7d6+ Qc7xd6 Qg7f7+ Qg8xf7 Qf6xf7+
  3/8	00:48	  14.425.096	303.686	-M3	Qb8xa7 Nf7d6+ Ne4xd6 Qf6xg6+ Qg8f7 Nd7f6+
  3/8	00:48	  14.425.096	303.686	-M3	Qb8xb7 Nf7d6+ Ne4xd6 Qf6xg6+ Qg8f7 Nd7f6+
  3/8	00:48	  14.425.096	303.686	-M3	Qb8a8 Nf7d6+ Ne4xd6 Qf6xg6+ Qg8f7 Nd7f6+
  3/8	00:48	  14.425.096	303.686	-M3	Qb5a6 Nf7d6+ Ne4xd6 Qf6xg6+ Qg8f7 Nd7f6+
  3/8	00:48	  14.425.096	303.686	-M3	Qb5f1 Nf7d6+ Ne4xd6 Qf6xg6+ Qg8f7 Nd7f6+
  3/8	00:48	  14.425.096	303.686	-M3	Qb5c4 Nf7d6+ Ne4xd6 Qf6xg6+ Qg8f7 Nd7f6+
  3/8	00:48	  14.425.096	303.686	-M3	Qb5a4 Nf7d6+ Ne4xd6 Qf6xg6+ Qg8f7 Nd7f6+
  3/8	00:48	  14.425.096	303.686	-M3	Qb5b3 Nf7d6+ Ne4xd6 Qf6xg6+ Qg8f7 Nd7f6+
  3/8	00:48	  14.425.096	303.686	-M3	Qb5b4 Nf7d6+ Qb4xd6 Qg7f7+ Qg8xf7 Qf6xf7+
  3/8	00:48	  14.425.096	303.686	-M3	Qb5xb6 Nf7d6+ Ne4xd6 Qf6xg6+ Qg8f7 Nd7f6+
  3/8	00:48	  14.425.096	303.686	-M3	Qb5a5 Nf7d6+ Ne4xd6 Qf6xg6+ Qg8f7 Nd7f6+
  3/8	00:48	  14.425.096	303.686	-M3	Qb5xd5 Nf7d6+ Qd5xd6 Qg7f7+ Qg8xf7 Qf6xf7+
  3/8	00:48	  14.425.096	303.686	-M3	Qb5c5 Nf7d6+ Qc5xd6 Qg7f7+ Qg8xf7 Qf6xf7+
  3/8	00:48	  14.425.096	303.686	-M3	Qd8xe7 Nf7d6+ Ne4xd6 Qf6xg6+ Qg8f7 Qg7xf8+
  3/8	00:48	  14.425.096	303.686	-M3	Qd8xc7 Be7xf8+ Nc6e7 Qf6xe7+ Ng6xe7 Qe6xe7+
  3/8	00:48	  14.425.096	303.686	-M3	Qd8xc7 Nf7d6+ Qc7xd6 Qg7f7+ Qg8xf7 Qf6xf7+
  3/8	00:48	  14.425.096	303.686	-M3	Rb1b4 Nf7d6+ Ne4xd6 Qf6xg6+ Qg8f7 Nd7f6+
  3/8	00:48	  14.425.096	303.686	-M3	Rb1b3 Nf7d6+ Ne4xd6 Qf6xg6+ Qg8f7 Nd7f6+
  3/8	00:48	  14.425.096	303.686	-M3	Rb1a1 Nf7d6+ Ne4xd6 Qf6xg6+ Qg8f7 Nd7f6+
  3/8	00:48	  14.425.096	303.686	-M3	Rb1f1 Nf7d6+ Ne4xd6 Qf6xg6+ Qg8f7 Nd7f6+
  3/8	00:48	  14.425.096	303.686	-M3	Rb1e1 Nf7d6+ Ne4xd6 Qf6xg6+ Qg8f7 Nd7f6+
  3/8	00:48	  14.425.096	303.686	-M3	Rb1d1 Nf7d6+ Ne4xd6 Qf6xg6+ Qg8f7 Nd7f6+
  3/8	00:48	  14.425.096	303.686	-M3	Rb1c1 Nf7d6+ Ne4xd6 Qf6xg6+ Qg8f7 Nd7f6+
  3/8	00:48	  14.425.096	303.686	-M3	Rd4d1 Nf7d6+ Ne4xd6 Qf6xg6+ Qg8f7 Nd7f6+
  3/8	00:48	  14.425.096	303.686	-M3	Rd4d3 Nf7d6+ Ne4xd6 Qf6xg6+ Qg8f7 Nd7f6+
  3/8	00:48	  14.425.096	303.686	-M3	Rd4xd5 Nf7d6+ Rd5xd6 Qg7f7+ Qg8xf7 Qf6xf7+
  3/8	00:48	  14.425.096	303.686	-M3	Rd4a4 Nf7d6+ Ne4xd6 Qf6xg6+ Qg8f7 Nd7f6+
  3/8	00:48	  14.425.096	303.686	-M3	Rd4b4 Nf7d6+ Ne4xd6 Qf6xg6+ Qg8f7 Nd7f6+
  3/8	00:48	  14.425.096	303.686	-M3	Rd4c4 Nf7d6+ Ne4xd6 Qf6xg6+ Qg8f7 Nd7f6+
  3/8	00:48	  14.425.096	303.686	-M3	Rg1g4 Nf7d6+ Ne4xd6 Qf6xg6+ Qg8f7 Nd7f6+
  3/8	00:48	  14.425.096	303.686	-M3	Rg1g3 Nf7d6+ Ne4xd6 Qf6xg6+ Qg8f7 Nd7f6+
  3/8	00:48	  14.425.096	303.686	-M3	Rg1c1 Nf7d6+ Ne4xd6 Qf6xg6+ Qg8f7 Nd7f6+
  3/8	00:48	  14.425.096	303.686	-M3	Rg1d1 Nf7d6+ Ne4xd6 Qf6xg6+ Qg8f7 Nd7f6+
  3/8	00:48	  14.425.096	303.686	-M3	Rg1e1 Nf7d6+ Ne4xd6 Qf6xg6+ Qg8f7 Nd7f6+
  3/8	00:48	  14.425.096	303.686	-M3	Rg1f1 Nf7d6+ Ne4xd6 Qf6xg6+ Qg8f7 Nd7f6+
  3/8	00:48	  14.425.096	303.686	-M3	Bc8xb7 Nf7d6+ Ne4xd6 Qf6xg6+ Qg8f7 Nd7f6+
  3/8	00:48	  14.425.096	303.686	-M3	Bf8xg7 Be7xd8+ Nc6e7 Qf6xe7+ Ng6xe7 Qe6xe7+
  3/8	00:48	  14.425.096	303.686	-M3	Nc6xe5 Be7xd8+ Bf8e7 Qg7xg8+ Ng6f8 Qg8xf8+
  3/8	00:48	  14.425.096	303.686	-M3	Nc6xe5 Be7xf8+ Qd8e7 Rc7xc8+ Qb8xc8 Qc3xc8+
  3/8	00:48	  14.425.096	303.686	-M3	Nc6xe5 Nf7d6+ Ne4xd6 Qf6xg6+ Qg8f7 Nd7f6+
  3/8	00:48	  14.425.096	303.686	-M3	Nc6xe7 Qf6xe7+ Qd8xe7 Rc7xc8+ Qb8xc8 Qc3xc8+
  3/8	00:48	  14.425.096	303.686	-M3	Nc6xe7 Nf7d6+ Ne4xd6 Qf6xg6+ Qg8f7 Nd7f6+
  3/8	00:48	  14.425.096	303.686	-M3	Nc6b4 Be7xd8+ Bf8e7 Qg7xg8+ Ng6f8 Qg8xf8+
  3/8	00:48	  14.425.096	303.686	-M3	Nc6b4 Be7xf8+ Qd8e7 Rc7xc8+ Qb8xc8 Qc3xc8+
  3/8	00:48	  14.425.096	303.686	-M3	Nc6b4 Nf7d6+ Ne4xd6 Qf6xg6+ Qg8f7 Nd7f6+
  3/8	00:48	  14.425.096	303.686	-M3	Nc6a5 Be7xd8+ Bf8e7 Qg7xg8+ Ng6f8 Qg8xf8+
  3/8	00:48	  14.425.096	303.686	-M3	Nc6a5 Be7xf8+ Qd8e7 Rc7xc8+ Qb8xc8 Qc3xc8+
  3/8	00:48	  14.425.096	303.686	-M3	Nc6a5 Nf7d6+ Ne4xd6 Qf6xg6+ Qg8f7 Nd7f6+
  3/8	00:48	  14.425.096	303.686	-M3	Nc6xa7 Be7xd8+ Bf8e7 Qg7xg8+ Ng6f8 Qg8xf8+
  3/8	00:48	  14.425.096	303.686	-M3	Nc6xa7 Be7xf8+ Qd8e7 Qf6xe7+ Ng6xe7 Qe6xe7+
  3/8	00:48	  14.425.096	303.686	-M3	Nc6xa7 Nf7d6+ Ne4xd6 Qf6xg6+ Qg8f7 Nd7f6+
  3/8	00:48	  14.425.096	303.686	-M3	Ng6h4 Qg7xf8+ Qg8xf8 Nf7d6+ Ne4xd6 Qf6xf8+
  3/8	00:48	  14.425.096	303.686	-M3	Ng6h4 Be7xd8+ Nc6e7 Qf6xe7+ Bf8xe7 Qg7xg8+
  3/8	00:48	  14.425.096	303.686	-M3	Ng6h4 Be7xf8+ Qd8e7 Qf6xe7+ Nc6xe7 Qe6xe7+
  3/8	00:48	  14.425.096	303.686	-M3	Ng6h4 Nf7d6+ Ne4xd6 Qg7xf8+ Qg8xf8 Qf6xf8+
  3/8	00:48	  14.425.096	303.686	-M3	Ng6h8 Qg7xf8+ Qg8xf8 Nf7d6+ Ne4xd6 Qf6xf8+
  3/8	00:48	  14.425.096	303.686	-M3	Ng6h8 Be7xd8+ Nc6e7 Qf6xe7+ Bf8xe7 Qg7xg8+
  3/8	00:48	  14.425.096	303.686	-M3	Ng6h8 Be7xf8+ Qd8e7 Qf6xe7+ Nc6xe7 Qe6xe7+
  3/8	00:48	  14.425.096	303.686	-M3	Ng6h8 Nf7d6+ Ne4xd6 Qg7xf8+ Qg8xf8 Qf6xf8+
  3/8	00:48	  14.425.096	303.686	-M3	Ng6f4 Qg7xf8+ Qg8xf8 Nf7d6+ Ne4xd6 Qf6xf8+
  3/8	00:48	  14.425.096	303.686	-M3	Ng6f4 Nf7d6+ Ne4xd6 Qg7xf8+ Qg8xf8 Qf6xf8+
  3/8	00:48	  14.425.096	303.686	-M3	Ng6xe5 Qg7xf8+ Qg8xf8 Nf7d6+ Ne4xd6 Qf6xf8+
  3/8	00:48	  14.425.096	303.686	-M3	Ng6xe5 Be7xd8+ Nc6e7 Qf6xe7+ Bf8xe7 Qg7xg8+
  3/8	00:48	  14.425.096	303.686	-M3	Ng6xe5 Be7xf8+ Qd8e7 Qf6xe7+ Nc6xe7 Qe6xe7+
  3/8	00:48	  14.425.096	303.686	-M3	Ng6xe5 Nf7d6+ Ne4xd6 Qg7xf8+ Qg8xf8 Qf6xf8+
  3/8	00:48	  14.425.096	303.686	-M3	Ng6xe7 Qg7xf8+ Qg8xf8 Nf7d6+ Ne4xd6 Qf6xf8+
  3/8	00:48	  14.425.096	303.686	-M3	Ng6xe7 Nf7d6+ Ne4xd6 Qg7xf8+ Qg8xf8 Qf6xf8+
  3/8	00:48	  14.425.096	303.686	-M3	g5g4 Nf7d6+ Ne4xd6 Qf6xg6+ Qg8f7 Nd7f6+
  4/8	00:48	  14.425.096	303.686	-M4	Qb5d3 Qg7xf8+ Qg8xf8 Nf7d6+ Ne4xd6 Qf6xg6+ Qf8f7 Nd7f6+
  4/8	00:48	  14.425.096	303.686	-M4	Qb5d3 Be7xd8+ Nc6e7 Qf6xe7+ Bf8xe7 Qg7xg8+ Ng6f8 Qg8xf8+
  4/8	00:48	  14.425.096	303.686	-M4	Qb5d3 Be7xf8+ Qd8e7 Qf6xe7+ Nc6xe7 Rc7xc8+ Qb8xc8 Qc3xc8+
  4/8	00:48	  14.425.096	303.686	-M4	Qb5d3 Nf7d6+ Ne4xd6 Qg7f7+ Qg8xf7 Qf6xf7+ Nd6xf7 Nd7f6+
  4/8	00:48	  14.425.096	303.686	-M4	Qd8xd7 Qe6xd7+ Bc8xd7 Qa7xb8+ Bd7c8 Bb7xc6+ Qb5xc6 Qf6xc6+
  4/8	00:48	  14.425.096	303.686	-M4	Qd8xd7 Qg7xf8+ Qg8xf8 Nf7d6+ Qd7xd6 Qf6xg6+ Qf8f7 Qg6xf7+
  4/8	00:48	  14.425.096	303.686	-M4	Qd8xd7 Be7a3+ Qd7e7 Bb7xc6+ Qb5xc6 Rc7xe7+ Bf8xe7 Qb6d8+
  4/8	00:48	  14.425.096	303.686	-M4	Qd8xd7 Be7b4+ Qd7e7 Bb7xc6+ Qb5xc6 Rc7xe7+ Bf8xe7 Qb6d8+
  4/8	00:48	  14.425.096	303.686	-M4	Qd8xd7 Be7xf8+ Qd7e7 Bb7xc6+ Qb5xc6 Rc7xe7+ Ng6xe7 Qf6xe7+
  4/8	00:48	  14.425.096	303.686	-M4	Qd8xd7 Nf7d6+ Ne4xd6 Qg7f7+ Qg8xf7 Qf6xf7+ Nd6xf7 Qf3xf7+
  4/8	00:48	  14.425.096	303.686	-M4	Qg8xg7 Be7xd8+ Bf8e7 Qf6xe7+ Nc6xe7 Qe6xe7+ Ng6xe7 Qe5xe7+
  4/8	00:48	  14.425.096	303.686	-M4	Qg8xg7 Be7xf8+ Qd8e7 Qf6xe7+ Nc6xe7 Rc7xc8+ Qb8xc8 Qc3xc8+
  4/8	00:48	  14.425.096	303.686	-M4	Qg8xg7 Nf7d6+ Ne4xd6 Qf6xg6+ Nd6f7 Qg6xf7+ Qg7xf7 Qf3xf7+
  4/8	00:48	  14.425.096	303.686	-M4	Bc8xd7 Qg7xf8+ Qg8xf8 Nf7d6+ Ne4xd6 Qf6xf8+ Ng6xf8 Qf3xf8+
  4/8	00:48	  14.425.096	303.686	-M4	Bc8xd7 Be7xd8+ Nc6e7 Qf6xe7+ Bf8xe7 Qg7xg8+ Ng6f8 Qe6xe7+
  4/8	00:48	  14.425.096	303.686	-M4	Bc8xd7 Be7xf8+ Nc6e7 Qf6xe7+ Qd8xe7 Qe6xe7+ Ng6xe7 Qe5xe7+
  4/8	00:48	  14.425.096	303.686	-M4	Bc8xd7 Nf7d6+ Ne4xd6 Be7xd6+ Bf8e7 Qg7f7+ Qg8xf7 Qf6xf7+
  8/8	00:48	  14.425.096	303.686	-M8	Qb5e2+ Qa2xe2 Rg1h1+ Qf3xh1 Rb1xh1+ Kh2xh1 Ne4f2+ Qe2xf2 Rd4d1+ Rd5xd1 Qg8h8+ Qg7xh8 Qd8xd7 Nf7d6+ Qd7xd6 Qf6f7+
  8/8	00:48	  14.425.096	303.686	-M8	Qb5b2+ Qc3xb2 Rg1h1+ Qf3xh1 Rd4d2+ Qb2xd2 Rb1xh1+ Kh2xh1 Ne4f2+ Qb6xf2 Qg8h8+ Qg7xh8 Qd8xd7 Nf7d6+ Qd7xd6 Qf6f7+
  8/8	00:48	  14.425.096	303.686	-M8	Qb5b2+ Qa2xb2 Rg1h1+ Qf3xh1 Rd4d2+ Qb2xd2 Rb1xh1+ Kh2xh1 Ne4f2+ Qd2xf2 Qg8h8+ Qg7xh8 Qd8xd7 Nf7d6+ Qd7xd6 Qf6f7+
  8/8	00:48	  14.425.096	303.686	-M8	Qg8h7+ Qg7xh7 Rg1h1+ Qf3xh1 Rd4d2+ Qc3xd2 Rb1xh1+ Kh2xh1 Ne4f2+ Qb6xf2 Qb5xd5+ Qa2xd5 Qd8xd7 Nf7d6+ Qd7xd6 Qh7f7+
  8/8	00:48	  14.425.096	303.686	-M8	Qg8h8+ Nf7xh8 Rg1h1+ Qf3xh1 Rd4d2+ Qf6f2 Rd2xf2+ Qb6xf2 Rb1xh1+ Kh2xh1 Ne4xf2+ Qa7xf2 Qb5xd5+ Qa2xd5 g5g4 Nd7f6+
  8/8	00:48	  14.425.096	303.686	-M8	Qg8h8+ Qg7xh8 Rg1h1+ Qf3xh1 Rd4d2+ Qa2xd2 Rb1xh1+ Kh2xh1 Ne4f2+ Qd2xf2 Qb5xd5+ Qe5xd5 Qd8xd7 Nf7d6+ Qd7xd6 Qf6f7+
  8/8	00:48	  14.425.096	303.686	-M8	Rb1b2+ Kh2xg1 Rb2b1+ Qa2xb1 Qb5xb1+ Qf3f1 Qb1xf1+ Qf6xf1 Qg8xg7 Nf7d6+ Ne4xd6 Qe6xg6+ Nd6f7 Qf1xf7+ Qg7xf7 Nd7f6+
  8/8	00:48	  14.425.096	303.686	-M8	Rb1b2+ Qc3xb2 Rg1h1+ Qf3xh1 Rd4d2+ Qh1g2 Rd2xg2+ Qb2xg2 Qg8h7+ Nf7h6 Qh7xh6+ Qg7xh6 Ne4d6 Qh6xg6+ Nd6f7 Qg6xf7+
  8/8	00:48	  14.425.096	303.686	-M8	Rb1b2+ Qa2xb2 Rg1h1+ Qf3xh1 Rd4d2+ Qh1g2 Rd2xg2+ Qb2xg2 Qg8h7+ Nf7h6 Qh7xh6+ Qg7xh6 Ne4d6 Qh6xg6+ Nd6f7 Qg6xf7+
  8/8	00:48	  14.425.096	303.686	-M8	Rd4d2+ Rd5xd2 Rg1h1+ Qf3xh1 Rb1xh1+ Kh2xh1 Ne4f2+ Qb6xf2 Qg8h8+ Qg7xh8 Qb5d5+ Qa2xd5 Qd8xd7 Nf7d6+ Qd7xd6 Qf6f7+
  8/8	00:48	  14.425.096	303.686	-M8	Rd4d2+ Qc3xd2 Rg1h1+ Qf3xh1 Rb1xh1+ Kh2xh1 Ne4f2+ Qb6xf2 Qg8h8+ Qg7xh8 Qb5xd5+ Qa2xd5 Qd8xd7 Nf7d6+ Qd7xd6 Qf6f7+
  8/8	00:48	  14.425.096	303.686	-M8	Rg1g2+ Qf3xg2 Rb1h1+ Qg2xh1 Rd4d2+ Qh1g2 Rd2xg2+ Qa2xg2 Qg8h7+ Nf7h6 Qh7xh6+ Qg7xh6 Ne4d6 Qh6xg6+ Nd6f7 Qg6xf7+
  8/8	00:48	  14.425.096	303.686	-M8	Rg1g2+ Qa2xg2 Rb1h1+ Qg2xh1 Rd4d2+ Qh1g2 Rd2xg2+ Qf3xg2 Qg8h7+ Nf7h6 Qh7xh6+ Qg7xh6 Ne4d6 Qh6xg6+ Nd6f7 Qg6xf7+
  8/8	00:48	  14.425.096	303.686	-M8	Rg1h1+ Qf3xh1 Rd4d2+ Qc3xd2 Rb1xh1+ Kh2xh1 Ne4f2+ Qb6xf2 Qg8h8+ Qg7xh8 Qb5xd5+ Qa2xd5 Qd8xd7 Nf7d6+ Qd7xd6 Qf6f7+
Less than 14.5 million nodes searched!

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

I use JetChess 1.0.0.0 perft counter to give an idea of the tree size of the original position (before playing 1.- Qdxe6):

Code: Select all

1qbqkbq1/QBRNBNQ1/1QnQpQn1/1q1RQ1p1/3rn3/2Q2Q2/Q6K/1r4r1 w - - 0 1

perft(1) =              99
perft(2) =           6,722
perft(3) =         602,875
perft(4) =      39,177,153
perft(5) =   3,545,566,008
perft(6) = 222,775,664,191

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

Unique positions:

positions(1) =          99
positions(2) =       6,722
positions(3) =     338,423
positions(4) =  13,324,447
positions(5) = 434,616,831
@Dann: thanks for the file and the comeback. ;)

Regards from Spain.

Ajedrecista.