Direct Mate in 5 problem set

[Dann Corbit]

http://rybkaforum.net/cgi-bin/rybkaforu ... pid=551213

There is no facility here for uploading files.
So I posted it elsewhere.

[sje]

Thank you for your work.

The first position in the dm5.epd file is:
[d]r2qkbr1/ppp2p1p/n3pnp1/1N1pB3/3P2b1/4PN2/PPP2PPP/R2QKB1R w KQq - 0 1[/d]
Symbolic says: No mate in five (or six or less).

[Ferdy]

http://rybkaforum.net/cgi-bin/rybkaforu ... pid=551213

There is no facility here for uploading files.
So I posted it elsewhere.

Run my position checker.

Code: Select all

Position  NoBM  IPawnLoc  INumPawn  INumPiece  IPaAndPie  IFen  IKing
  117846     0         0         0          2        751     0      0

INumPiece: Illegal number of pieces, there are 2 here.

[d]QqQqQqBk/Q5qB/q6Q/Q6q/q6Q/Q6q/q5Qb/qQqQqQbK b - -
[d]QqQqQqBk/Q5qB/q6Q/Q6q/q6Q/Q6q/q5Qb/qQqQqQbK w - -

IPaAndPie: Illegal number of pieces and pawns combined, there are 751 pos.

Samples.
[d]2R5/bbP3P1/kbb5/bb1BBB2/3BBB2/3BBB2/1bQ1KQ2/b7 w - -
[d]rnqbk2r/pp2n1P1/8/2pp2Np/2PPp3/7Q/PP2PP1P/RNQBK2R w - - 0 1

Also trying to convert the bm to uci move notation, I found 7 pos with illegal and invalid san as detected by PCL. See Opcode c9 for the actual error.

Code: Select all

r2qkbr1/ppp2p1p/n3pnp1/1N1pB3/3P2b1/4PN2/PPP2PPP/R2QKB1R w KQq - acd 123; acs 1104; bm Bh4; ce 32758; dm 5; pm Nc3 {52} h3 {8} Be2 {2} Bd3 {1} a3 {1}; pv Bh4 gxh4 Nb3 cxb3 c4+ bxc3 Ra4 g5 e4+; c9 "("illegal san: 'Bh4'",)";
8/7p/6pP/5pP1/3BpP2/p1KpP3/pn1N4/k7 w - - acd 75; acs 898; bm Kh5; ce 32758; dm 5; id "yacpdb id 67684"; pm Kh5; pv Kh5 Ba2 Kh6 Bb3 Kh7 Ba2 Kh8 Rxc6 Qh7+; c9 "("illegal san: 'Kh5'",)";
5R2/2P2pK1/2P2P2/1Pp1BP1P/b6p/1p1RPB2/1p2NPn1/6rk w - - acd 104; acs 830; bm Kc1; ce 32758; dm 5; id "ChestDB.0672"; pm Kc1; pv Kc1 Bc6 Kd1 b5 Ke1 Bd7 Kf2 a5 Rg3+; c9 "("illegal san: 'Kc1'",)";
n2Bqk2/5p1p/Q4KP1/p7/8/8/8/8 w - - acd 119; acs 631; bm Bh4; ce 32758; dm 5; id "yacpdb id 276295"; pm Bh4; pv Bh4 gxh4 Nb3 cxb3 c4+ bxc3 Ra4 g5 e4+; c9 "("illegal san: 'Bh4'",)";
k7/P5P1/1PP5/K3b2q/R7/1b6/8/8 w - - acd 51; acs 161; bm g8Q+; ce 32758; dm 5; id "yacpdb id 286296"; pm g8Q+; pv g8Q+ Bb8+; c9 "("invalid san: 'g8Q+'",)";
8/8/8/8/8/3p4/4pk2/K7 b - - acd 99; acs 0; bm e1Q+; ce 32758; dm 5; pm e1Q+; pv e1Q+ Ka2 Qc3 Kb1 d2 Ka2 d1N Kb1 Qb2+; c9 "("invalid san: 'e1Q+'",)";
r1b1k1r1/2qnpR2/p1p3p1/4Nn2/3PN3/1B6/PP4Q1/2K4R w - - acd 11; acs 0; bm g2g6; ce 32758; dm 5; id "MG 1679"; pm Qxg6; pv Qxg6 Nh6 Rg7+ Kd8 Rxg8+ Nxg8 Qxg8+ Nf8 Qxf8#; c9 "("illegal san: 'g2g6'",)";

[Dann Corbit]

There are thousands of such positions in chess problem databases. They do not suffer from the same limitations as ordinary chess.

I remove all that I find, but those slipped through the net.

I also removed several hundred with things like pawns on ranks 1 and 8, three kings on the board, no kings on the board, etc.

Often the problems are not even checkmate problems (they can be helpmate or proof games or lots of other things).

The games in the pile are those that passed my simple checks and that I also resolved to checkmate with either a mate engine or with an ordinary chess engine.

As for the circle problems, they are pretty to me so I don't think I will remove them from my database, but I should probably remove them from my problem set.

Thanks for going over the problem set for me. This sort of input is very useful.

I also find it very therapeutic to go over the problems by hand. A lot of them are very obvious and a human can solve them quickly. But some are much more subtle. There are even mate in three problems that can give me pause (though I am sure that Kasparov and the like could solve them in an eyeblink).

[Dann Corbit]

Thank you for your work.

The first position in the dm5.epd file is:
[d]r2qkbr1/ppp2p1p/n3pnp1/1N1pB3/3P2b1/4PN2/PPP2PPP/R2QKB1R w KQq - 0 1[/d]
Symbolic says: No mate in five (or six or less).

You are right. That is not a mate in 8 or less. I checked it out with Chest.

I wonder how it even got in there, because I reprocessed the file with Chest.
It must have been something I had in the windows clipboard and accidentally hit a paste operation or something.

[Dann Corbit]

That problem is a real mystery.
Even the first move is illegal.

r2qkbr1/ppp2p1p/n3pnp1/1N1pB3/3P2b1/4PN2/PPP2PPP/R2QKB1R w KQq - acd 123; acs 1104; bm Bh4; ce 32758; dm 5; pm Nc3 {52} h3 {8} Be2 {2} Bd3 {1} a3 {1}; pv Bh4 gxh4 Nb3 cxb3 c4+ bxc3 Ra4 g5 e4+;

I have no idea what happened here.