To be clear, I still collect positions but think I am going to leave my test set in the state it is in for a while. So .. you are welcome to use these.
MikeGL wrote:Thanks. Very interesting positions.
Some of my observations after making manual analysis with engine assistance.
position 1> 1.d5! is good, but looks like 1.Rxe6! is just as good and forceful, where after 5 further
moves the eval score also becomes greater than +3 with a beautiful
attacking game for white. While 1.d5 goes to endgame R vs B.
position 3> 1.Nxg5 was also played by Anand-So if my memory serves me right because I was observing this game live during that super tourn
where Anand went on to win the game 1-0.
position 5> 1.Rb1 and 1.Qh4 would transpose into the same line, so maybe 2 bm for this position.
position 7> 1.Bxh7+ is not very convincing, after playing with stockfish score goes to +0.22 with possible fortress or draw because R+N vs Q seems to hold for black.
All the others seems correct, at least according to my shallow analysis
using SF on a weak hardware.
.
Sorry, got confused, position 5> 1.Qh4 move cannot win.
After search on several forums and in the archives, I found several interesting positions. (Sorry for the draft mode).
The new suite will be in 2 parts :
1) normal positions : tactics, endgames, attack, ...
2) special positions : fortress, zugzwangs, shortest mates, score verifications ...
8/4r1pk/2B5/1P3P2/2PrPb1p/6qP/1R1p2P1/3R2QK b - - 0 47
But finally, after 47...Ra7 48.Rbb1 Ra3 it gives a convincing score :
Stockfish_170801_x64_modern:
34/62 02:19 1 536 159k 10 974k -4,46
Be4 is very hard to find for SF (Zugzwang).
8/p5pq/8/p2N3p/k2P3P/8/KP3PB1/8 w - - bm Be4;
Nxf6 missed by DisasterArea
4r2r/pppkq1pp/2n1pn2/4p1B1/4N2Q/8/PPP3PP/4RRK1 w - -
35+ 22:31 16,005,973,686 11,847,130 +0.98 Nxf6+ gxf6 Bxf6
Waiting for a mate score, black has no perpetual :
kB5K/2P4B/P4rP1/4r3/2N1n3/1RP4N/3b4/6RQ b - - 0 1
Waiting for a mate score, black has no perpetual :
[Event "Schakend Nederland"]
[Site "?"]
[Date "1990.??.??"]
[White "Van Breukelen, G."]
[Black "[+]"]
[Result "1-0"]
[SetUp "1"]
[FEN "1r4Q1/7p/2N1B2k/7P/3Pp1P1/K1N1P2R/PP2PR2/8 b - - 0 1"]
[PlyCount "200"]
The winning move that he played is (apparently) f5!! and he commented that even today's strong engines take a bit of time to find it.
My apologies if this position has been discussed here before. I just thought it would be interesting to post it.
r1b3k1/ppppn1pp/4n1q1/8/5P2/2N1B3/PPP3QP/3R1RK1 w - - 19
r1b3k1/pppp2pp/4n1q1/5n2/8/2N1B3/PPP3QP/3R1RK1 w - - 0 10
here still SF takes some time to find Rxf5!!
Nbxa7+ mate in 8 (joke )
brkrqbqn/qnpNqqbr/bnNqRbrn/qNrrnRrb/BrqnbqRr/bqRNnprR/QQbNNrNn/bqrnRbKb w - - 0 1
8/1k4p1/3p1pPp/1P2pP1P/2n1P3/3K4/2B5/8 b - - bm d5;
6Q1/8/3p4/2pPk1p1/1p5P/1P4PK/2q5/8 b - - 0 1
Well-known from many test suites. Houdini and Komodo find mating -g4+ almost instantly, but SF8 not in 5 minutes.
6k1/8/1pK4p/bPp5/8/1P6/P1B2P2/8 w - - 0 1
4 runs with SF on a 6*4GHz : 13 sec, 7min5sec, 1min47sec and 45 sec
FEN: 6k1/8/1pK4p/bPp5/8/1P6/P1B2P2/8 w - - 0 1
2kr3r/1p3pb1/pBnqp2p/P2p2p1/8/2PB4/1P3PPP/R2Q1RK1 w - - bm b4;
6q1/PpB5/k7/P6K/6n1/1P4p1/5p2/1B3N1N w - - bm a8=Q+ a8=R+;
q7/7R/k7/1p6/1p6/1P2B3/7K/8 w - - bm Bd4;
1B1k4/3p4/1Kp5/PpP2p2/1PqP1P2/8/1P6/8 w - - bm a6;
8/2B2k2/6p1/5P1p/6p1/p1p3PP/6P1/1n2K2R w K - bm fxg6+;
8/3ppp1p/3P4/4N3/8/3n1pKp/8/7k w - - bm Nxd3;
r1b4r/p4pk1/P3p1p1/1pBpPnPp/2pP1K2/2P3P1/4BP2/R6R w - - bm g4;
8/p7/5k2/pPp1p3/2P3KP/8/8/3Bb3 b - - bm Bxh4;
q7/8/2p5/B2p2pp/5pp1/2N3k1/6P1/7K w - - bm Ne4+;
4rb2/1p1q1ppk/p1n1p2p/2p1Pn2/3PNR2/2P2K2/P2QBP2/6R1 w - - bm Rxf5;
r1b2rk1/2q1bppp/pp2p3/2npP3/1n3P1P/2NBBN2/PPPQ2P1/1K1R3R w - - bm Bxh7;
r4rk1/pb3pp1/1p1qpR2/2ppN3/3P4/2P4P/PP1pQ1P1/3R2K1 w - - bm Qxd2 Ng4;
rn1q1rk1/2pbb3/pn2p3/1p1pPpp1/3P4/1PNBBN2/P1P1Q1PP/R4R1K w - - bm Nxg5; id "arasan19.16"; c0 "Dann Corbit, CCC 2015";
rn1qr1k1/1p2bppp/p3p3/3pP3/P2P1B2/2RB1Q1P/1P3PP1/R5K1 w - - bm Bxh7+; id "arasan19.42"; c0 "Polugaevsky-Torre, London 1984";
8/4nk2/1p3p2/1r1p2pp/1P1R1N1P/6P1/3KPP2/8 w - - bm Nd3; id "arasan19.116"; c0 "Grandelius-Raznikov, EU Youth Chess Ch B18, Albena 2011";
3r1r1k/pp5p/4b1pb/6q1/3P4/4p1BP/PP2Q1PK/3RRB2 b - - bm Qxg3+; id "arasan19.137"; c0 "Apicella-Lautier, Clichy 2001";
r1b2rk1/1pq1nppp/pbn1p3/8/3N4/3BBN2/PPP1QPPP/3R1RK1 w - - bm Bxh7+; id "arasan19.159"; c0 "Leu-Muck, DDR-ch H137 corr 1973";
r1b3r1/5p1k/p1n2P1p/P1qpp1P1/1p1p4/3P2Q1/BPPB2P1/R4RK1 w - - bm Kf2; id "arasan19.179"; c0 "Efremov-Fischer, Danube/4 ICCF 2012";
4K1k1/8/1p5p/1Pp3b1/8/1P3P2/P1B2P2/8 w - - bm f4; id "arasan19.189"; c0 "?achová skladba 2011-12, 1st Prize";
In the following position, Nc4!! is winning and hard to find by computers.
1r2kb1r/p5p1/1np1p1N1/3pPnB1/1p1P2B1/qP6/2PQ1P1P/1K1R3R b k - 0 20
Video and posts about this sacrifice : https://lichess.org/forum/game-analysis ... win?page=1
I found this position : b6!!
8/8/8/1P1K3b/6p1/5pP1/5P1B/7k w - - 1 1?
on a youtube channel
and I wanted those of you with mega-hardware to see if the top engines can solve it.
--> http://www.talkchess.com/forum/viewtopi ... 037#718037
8/1P6/8/1b1K4/6p1/5pP1/5P1B/7k w - - 1 3
Here, the point is to find find b8=R.
SF on 3 runs on 6*4GHz : 18 seconds, 50 sec and 30 sec.
draw pawn EG : support passed pawn vs 2 pawn defends each other
8/8/1P1k3p/3P2pP/4KpP1/8/8/8 w - - 1 71
Still under investigation :
r2r1q1k/5p1p/4pP2/pppbB2Q/1b6/1P4P1/5PBP/R2R2K1 w - - 0 24
1) after 24.Rxd5! exd5 25.Rd1, (a4 and Qg8 seems the best replies)
This is a fun position, but too many major pieces:
[d]brkrqbqn/qnpNqqbr/bnNqRbrn/qNrrnRrb/BrqnbqRr/bqRNnprR/QQbNNrNn/bqrnRbKb w - -
I guess that if an engine barfs on it, it is not the engine's fault.
And we can also have silent over-writes if an array bound is exceeded.
While personally, I think it would be nice if engines could tolerate 62 of every major piece but king, I suspect that many will have a hard time with non-legal piece counts.
Taking ideas is not a vice, it is a virtue. We have another word for this. It is called learning.
But sharing ideas is an even greater virtue. We have another word for this. It is called teaching.
[d]qqqkqqqq/qqqqqqqq/qqqqqqqq/qqqqqqqq/qqqqqqqq/QQQQQQQQ/QQQQQQQQ/QQQQQQQQ/QQQKQQQQ w - -
I guess that there are very few programs that won't pop a cork on reading this position into memory.
Probably 75% or more will simply print a diagnostic and exit.
Taking ideas is not a vice, it is a virtue. We have another word for this. It is called learning.
But sharing ideas is an even greater virtue. We have another word for this. It is called teaching.
ASMfish found it in 10 minutes yesterday in my 6 scores ...
)