Henk wrote:Do you know a list of fens which are positions any weak playing engine should be able to solve ?
I assume you mean "solve relatively quickly", as in within 30 seconds. Here are several that I use to make sure Myrddin isn't broken. Myrddin finds most of these in less than 5 seconds, but is only rated about 2360 CCRL.
This is Fine 70, perfect for testing if your transposition table is broken
8/k7/3p4/p2P1p2/P2P1P2/8/8/K7 w - - 0 1 bm Kb1
This is a mate in 7 that your engine should get very quickly if you have extensions for both check and single reply
7k/3b3p/1p6/3p1P1P/2p3r1/2P1R3/7r/2RK4 b - - 0 40 bm Rg1, Ba4
Two easy to find mate in 5 positions
R7/5k2/3p4/4p3/1P3p1R/8/2P4K/8 w - - 0 45 bm Rh6
6k1/8/5pB1/4b2p/3rP2P/2K1R1P1/1r2R3/8 b - - 0 57 bm Rd7, Rd8
Mate in 10 that isn't too hard to find
3R4/2r5/6rp/2k5/p1p2p1P/P1Rp1P2/1P6/5K2 b - - bm Rcg7
Find the move that delays mate as long as possible. Good for engines that have a series of aspiration windows before using a full-window search
8/3kp3/Q7/4p3/4K3/6p1/PP4P1/8 b - - 0 43 bm Ke8
And then several others that have different uses
r4r2/p1q1n1kp/2n1ppp1/8/3P2N1/3BPP2/2Q2P1P/R3K2R w KQ - 0 19 bm h3, h4
2q3k1/R2bprbp/3n2p1/3P4/P2NP3/5P2/1r3BPP/3Q1RK1 b - - 0 21 bm Nxe4
4r1k1/2r1pp1p/pp4p1/3b4/PB1b2N1/8/5PPP/3RR1K1 b - - 0 25 bm Bg7
1r5k/q1p3p1/3b1p1p/8/p1P4N/3Q1PP1/2P3K1/7R b - - 0 30 am a3
4r1k1/pp1b1pp1/1q1b1p2/3P4/2Q2PP1/P1N5/RP2N3/7K b - - 0 22 bm Qf2
r1bqr1k1/p2p1pp1/1p5p/2pP3Q/1n2p3/1P2P1P1/PB1P1PP1/R3KB1R w KQ - bm Bg7
3b2k1/3Prp1p/R5p1/p7/2Bp4/1P3P2/P5PP/6K1 w - - 0 40 bm Bb5
1k2r3/p2BPb1p/5P2/2p2P2/Pp6/5P2/1P1B3P/n3K3 w - - 0 32 bm Be6, Bf4
6k1/4bpp1/R7/2p1P3/6qP/1P4B1/7P/1R4K1 b - - 0 36 bm c4
8/8/4kp1p/R7/4N2P/p4rP1/6K1/3b4 w - - 0 52 bm Nf2
r4rk1/1p2ppbp/pq1p2p1/3P4/1nP3n1/2N2N2/PP2QPPP/R1B2RK1 b - - 0 18 bm a5
8/pR5p/4k3/2P1B3/5P1r/4P3/P2r4/2R3K1 w - - 0 34 am Qxa7 bm Rb2, Rg7
2r1r1k1/5p2/p3pbpB/1p1pP3/3p2P1/n1q2B2/2P2PK1/4R2R w - - bm exf6
3r1r1k/1b4pp/ppn1p3/4Pp1R/Pn5P/3P4/4QP2/1qB1NKR1 w - - bm Rxh7
jm