TalkChess.com

My project sting is dedicated to solve difficult studies, and not middle-game tactical positions.

download: http://www.mediafire.com/file/ueo9u9hjl ... 1.zip/file

There are a few important modifications.
Also I added an old code ("lazy King") tried by me earlier.

The "IQ" test is a very important part of my project (Sting) and doesn't contain middle-game tactical positions and technical endgames.
Here are positions dedicated to all engines to test so-called by me "quasi-intelligent" their abilities.

Don't use such external tricks like: rule-50 changing, null-move disabling, special parameters and others.
The external tools like: MultiPV, tablebases, "backward-forward" and "Monte Carlo" are not welcome too.

"WIN" means the correct solution and some non-zero score.
Don't do the test in a machine way. Test and analyze each of items separately!

[pgn]
[Result "1"]
[FEN "rk6/p1r3p1/P3B1Kp/1p2B3/8/8/8/8 w - - 0 1"]

1. Bd7 {win}

[Result "2"]
[FEN "7k/6rp/6pN/1r4P1/3B4/8/8/K7 b - - 0 1"]

1... Rxg5

[Result "3"]
[FEN "1B1k4/3p4/1Kp5/PpP2p2/1PqP1P2/8/1P6/8 w - - 0 1"]

1. a6 {win}

[Result "4"]
[FEN "3N2r1/2K1p3/4Pk2/8/Bp5b/8/2P5/8 b - - 0 1"]

1... Bg3 2. Kd7 {or Kc8} Rxd8

[Result "5"]
[FEN "8/7p/5P1k/1p5P/5p2/2p1p3/P1P1P1P1/1K3Nb1 w - - 0 1"]

1. Ng3

[Result "6"]
[FEN "6q1/PpB5/k7/P6K/6n1/1P4p1/5p2/1B3N1N w - - 0 1"]

1. a8Q {or a8R}

[Result "7"]
[FEN "6k1/6p1/4Rb1p/p7/rp2P1N1/2P3P1/1P5P/6K1 b - - 0 1"]

1... Bxc3

[Result "8"]
[FEN "8/8/p2k1p2/1p1p3p/1P1P3p/P3NPP1/5K2/1b6 w - - 0 1"]

1. Ng2

[Result "9"]
[FEN "2k5/p7/Pp1p1b2/1P1P1p2/2P2P1p/3K3P/5B2/8 w - - 0 1"]

1. c5

[Result "10"]
[FEN "1n6/Pp1p1p1p/1P1P1P1P/4K3/2p5/p7/rpp1P3/qkb1R3 w - - 0 1"]

1. axb8N {win}

[Result "11"]
[FEN "1N4K1/1pp1p3/7k/2r3pP/p2pp1P1/P6N/8/2B5 w - - 0 1"]

1. Nc6

[Result "12"]
[FEN "5K2/k4p1p/5p1p/1p3p2/bP6/1p6/1P5p/7B w - - 0 1"]

1. Ke8 {or Ke7 win}

[Result "13"]
[FEN "k1b5/1p1p1p1p/1PpPpP2/2B5/8/2p1p2P/2PbP3/3K4 w - - 0 1"]

1. Bd4 {win}

[Result "14"]
[FEN "8/8/8/8/1kB1q3/8/1PRb4/1K6 b - - 0 1"]

1... Qh1 2. Ka2 Qa8 3.Kb1 Qe4 {or other way to get the start position for

white: 8/8/8/8/1kB1q3/8/1PRb4/1K6 w - - 0 1}

[Result "15"]
[FEN "8/2N4r/1p3pkp/8/5K1p/2P4N/P3Bn2/8 w - - 0 1"]

1. Bh5

[Result "16"]
[FEN "4k1rr/1R1R3p/8/8/8/2K5/7P/8 w k - 0 1"]

1. Rd2

[Result "17"]
[FEN "5k2/4bp2/2B3p1/1P4p1/3R4/3P2PP/2r2PK1/8 b - - 0 1"]

1... Rxf2

[Result "18"]
[FEN "1b6/2p5/1kB5/1PN5/8/3K4/8/q7 w - - 0 1"]

1. Nb3

[Result "19"]
[FEN "N7/8/2KQ2rp/6k1/3p3p/2p4P/4PP2/5N2 w - - 0 1"]

1. f4

[Result "20"]
[FEN "2br4/r2pp3/8/1p1p1kN1/pP1P4/2P3R1/PP3PP1/2K5 w - - 0 1"]

1. Nf7 Re8 2. Nd6

[Result "21"]
[FEN "8/8/4B3/6p1/7k/8/4pPKP/8 w - - 0 1"]

1. Bg4

[Result "22"]
[FEN "r7/7k/5R2/p3p3/Pp1pPp2/1PpP1Pp1/K1P3P1/8 w - - 0 1"]

1. Kb1 Kg7 {or 1... Rh8 2. Rf8} 2. Rh6

[Result "23"]
[FEN "1K3kB1/8/6p1/7R/8/4b3/8/6n1 w - - 0 1"]

1. Rh8 Kg7 2. Bh7

[Result "24"]
[FEN "8/8/R7/1b4k1/5p2/1B3r2/7P/7K w - - 0 1"]

1. h4 Kxh4 2. Rh6 Kg5 3. Rh5

[Result "25"]
[FEN "7Q/4p3/4p3/p1p1P3/Pp2P3/3Kp3/p1PbP3/kN6 w - - 0 1"]

1. Na3 bxa3 2. Qh1 Kb2 3. Qa1 Kxa1 4. c4

[Result "26"]
[FEN "7r/K7/5k1n/p3p3/Pp1pPp1p/1PpP1PpP/2P3P1/N1RR1B2 b - - 0 1"]

{win}

[Result "27"]
[FEN "q7/b1p5/kp1p4/p2PN3/PPP5/1K6/8/5B2 w - - 0 1"]

1. c5 Kb7 2. Ba6 {win}

[Result "28"]
[FEN "1k1n4/1p1b1p2/1Bp1pPp1/1PP1P3/8/6P1/8/1K6 w - - 0 1"]

1. Bc7 {win}

[Result "29"]
[FEN "4q1kr/p6p/1prQPppB/4n3/4P3/2P5/PP2B2P/R5K1 w - - 0 1"]

1. Qxe5 {win}

[Result "30"]
[FEN "q1b4n/1p1pKp2/1p1p1Pp1/1P1P2Pp/2P4P/8/7R/1N1k4 w - - 0 1"]

1. Ra2 {win}

[Result "31"]
[FEN "3k4/2pq3p/pp5R/4P3/P6P/2PN4/1PN3K1/8 w - - 0 1"]

1. Nd4 {win}

[Result "32"]
[FEN "8/7p/6pP/p4pP1/3BpP2/p1KpP3/pn1N4/k7 w - - 0 1"]

1. Bh8 {win}

[Result "33"]
[FEN "8/6p1/p7/rp1K2p1/kb3pP1/2p2p1b/P1Np1P2/3N2R1 w - - 0 1"]

1. Ke6 {or Ke4 win}

[Result "34"]
[FEN "B7/p1p5/k2p4/p3p3/P1Nb1p2/6p1/7p/4K3 w - - 0 1"]

{Ke1->h3->c8}

[Result "35"]
[FEN "1qN5/b1pB4/1pP2k2/pP3P2/P1P5/8/8/K7 w - - 0 1"]

{Ka1->h5->d8}

[Result "36"]
[FEN "8/3P3k/n2K3p/2p3n1/1b4N1/2p1p1P1/8/3B4 w - - 0 1"]

1. Nf6

[Result "37"]
[FEN "8/5K2/3p3p/3p3P/pp1P4/rkb1R3/p1p3P1/n1B2B2 w - - 0 1"]

1. Rd3 {win}

[Result "38"]
[FEN "6bn/p4p1k/rp3Pp1/rp2BBP1/1p6/pK6/P2P4/8 w - - 0 1"]

1. Bc8 {win}

[Result "39"]
[FEN "qn6/b1Kp3p/p1pB3p/p7/P1NkP3/2pP4/2B5/8 w - - 0 1"]

1. Bf4 {or Kc8 - win}

[Result "40"]
[FEN "8/P7/4k3/8/5P2/4Bq2/5P2/5K2 b - - 0 1"]

1... Kf5

[Result "41"]
[FEN "8/6kP/1p6/p7/Pr6/K2B4/8/8 b - - 0 1"]

{Rb4->h4 and next Kg7->e5}

[Result "42"]
[FEN "8/8/2b1N3/5p2/3B4/2K5/6kp/R7 w - - 0 1"]

1. Rh1

[Result "43"]
[FEN "8/8/4kpp1/3p1b2/p6P/2B5/6P1/6K1 b - - 0 1"]

1... Bh3

[Result "44"]
[FEN "5rk1/5ppp/p1Q1p3/1R6/q7/4b1P1/P2RPP1P/6K1 w - - 0 1"]

1. Rd8 {win}

[Result "45"]
[FEN "r7/1b1r4/k1p1p1p1/1p1pPpPp/p1PP1P1P/PP1K4/8/4Q3 w - - 0 1"]

1. Qa5

[Result "46"]
[FEN "3B4/1r2p3/r2p1p2/bkp1P1p1/1p1P1PPp/p1P4P/PPB1K3/8 w - - 0 1"]

1. Ba4

[Result "47"]
[FEN "2k5/2p5/1q1p4/pPpPp1pp/N1P1Pp2/P4PbP/KQ4P1/8 w - - 0 1"]

{avoid Nxb6}

[Result "48"]
[FEN "1r6/4k3/r2p2p1/2pR1p1p/2P1pP1P/pPK1P1P1/P7/1B6 b - - 0 1"]

1... Rxb3

[Result "49"]
[FEN "8/5k2/6p1/4BP1p/6p1/p1p3PP/6P1/1n2K2R b K - 0 1"]

1... a2 2. fxg6 Kg8

[Result "50"]
[FEN "8/3k1b1r/2p1p1p1/rpPpPpPp/p2P1P1P/P2K4/8/4B3 w - - 0 1"]

1. Bb4

[Result "51"]
[FEN "7b/p1p1p3/P1PpPp2/2nP1kpr/5P1p/p3KBPP/P7/8 w - - 0 1"]

1. Be4

[Result "52"]
[FEN "7r/p1p1p1pk/3pPp1p/2pP1PP1/P1P4P/1K6/P6B/8 w - - 0 1"]

1. g6 Kg8 2. a5 a6 3. Bxd6 cxd6 4. h5 {or 2. Bxd6 cxd6 3. h5}

[Result "53"]
[FEN "8/1p1q1k2/1Pp5/p1Pp4/P2Pp1p1/4PpPp/1N3P1P/3B2K1 w - - 0 1"]

1. Bb3 Qc8 2. Nd1 Qa8 3. Bc4

[Result "54"]
[FEN "8/8/2pk4/8/p1p3B1/PpP5/1P6/r1NK4 w - - 0 1"]

1. Bf5 Ra2 2. Nxa2 bxa2 3. Kc1 a1Q 4. Bb1

[Result "55"]
[FEN "1R3b2/5ppQ/6Pp/6PP/R6P/P7/7K/2q1k3 w - - 0 1"]

1. Rb1 Qxb1 2. gxf7

[Result "56"]
[FEN "Kn6/8/8/3R2PB/8/2p2NP1/1q6/2k5 w - - 0 1"]

1. Rd1

[Result "57"]
[FEN "1B3B1B/2B5/p6B/8/8/8/8/1k1K4 w - - 0 1"]

1. Bce5

[Result "58"]
[FEN "4kr2/5p1K/3p1Q2/1p4P1/4P3/1PP5/7b/8 w - - 0 1"]

1. Kh6 {win}

[Result "59"]
[FEN "6R1/8/2pB3k/2P4p/5p1q/5P2/4P1K1/8 w - - 0 1"]

1. Bf8 {win}

[Result "60"]
[FEN "n2Bqk2/5p1p/Q4KP1/p7/8/8/8/8 w - - 0 1"]

1. Qc8 Kg8 2. Bc7 {win}

[Result "61"]
[FEN "8/5p2/8/8/p7/rpK4p/1p3ppr/bQ1N1bqk w - - 0 1"]

1. Kb4 {or Kd4 win}

[Result "62"]
[FEN "8/8/7p/3KNN1k/2p4p/8/3P2p1/8 w - - 0 1"]

1. Kc6

[Result "63"]
[FEN "1R6/pPk1r3/2p5/K7/8/2B1b3/8/8 w - - 0 1"]

1. Ka6

[Result "64"]
[FEN "8/p7/qkpN1p2/8/1B1P4/PP3K2/5P2/8 w - - 0 1"]

1. Ba5 {win}

[Result "65"]
[FEN "2N5/p7/P7/8/1KPp1p1p/3p1Bpp/3P2rq/R5bk w - - 0 1"]

1. Nb6 {win}

[Result "66"]
[FEN "5kN1/3p1q2/5P2/5PP1/2pK4/1p1R4/1P6/8 w - - 0 1"]

1. Rxb3

[Result "67"]
[FEN "2b1rk2/5p2/p1P5/2p2P2/2p5/7B/P7/2KR4 w - - 0 1"]

1. f6

[Result "68"]
[FEN "2r5/prkpR1p1/2p1ppK1/P1p1N1B1/P1P1P3/8/8/8 w - - 0 1"]

1. Bf4

[Result "69"]
[FEN "rk1b4/p2p2p1/1P6/2R2P2/8/2K5/8/5B2 w - - 0 1"]

1. Rc8 {win}

[Result "70"]
[FEN "3k4/4pp2/n2n4/5BN1/3N4/b7/4K3/8 w - - 0 1"]

1. Nxf7

[Result "71"]
[FEN "4b3/8/1P6/3K4/6p1/5pP1/5P1B/7k w - - 0 1"]

1. b7 Bb5 2. b8R

[Result "72"]
[FEN "8/5pKN/5Pp1/5kP1/8/Bb6/8/7q w - - 0 1"]

1. Bc5 {or any move} Qxh7+

[Result "73"]
[FEN "8/p5p1/1pP3p1/p5p1/k3p3/4p3/K7/8 w - - 0 1"]

1. c7 {win}

[Result "74"]
[FEN "q7/8/2p5/B2p2pp/5pp1/2N3k1/6P1/7K w - - 0 1"]

1. Ne4 Kh4 2. Ng3 fxg3 3. Bb6

[Result "75"]
[FEN "q7/7R/k7/1p6/1p6/1P2B3/7K/8 w - - 0 1"]

1. Bd4 {win}

[Result "76"]
[FEN "1q1r3k/3P1pp1/ppBR1n1p/4Q2P/P4P2/8/5PK1/8 w - - 0 1"]

1. Rxf6

[Result "77"]
[FEN "1r3q1k/2N2P1p/6pQ/4p3/7p/n6P/3B4/7K w - - 0 1"]

1. Qf4 {win}

[Result "78"]
[FEN "5nr1/2Pp2pk/3Pp1p1/4P1P1/6P1/5K2/8/7n w - - 0 1"]

1. c8N

[Result "79"]
[FEN "2K3k1/1p6/R3p1p1/1rB1P1P1/8/8/1Pb5/8 w - - 0 1"]

1. Rc6

[Result "80"]
[FEN "4q3/2r1r2p/3P3P/1p6/kP6/Pp6/1P6/KB2R3 w - - 0 1"]

1. Rxe7 Qxe7 {or 1... Rxe7 2. dxe7} 2. dxc7

[Result "81"]
[FEN "3k4/8/7p/2p1p1pP/1pPpPpP1/1P1P1P2/N7/2K5 w - - 0 1"]

{Na2->h4}

[Result "82"]
[FEN "8/8/8/1k3p2/p1p1pPp1/PpPpP1Pp/1P1P3P/QNK2NRR w - - 0 1"]

{win}

[Result "83"]
[FEN "4b1k1/P4pPp/1R3P1P/2r5/8/1P6/1K6/8 w - - 0 1"]

1. a8B

[Result "84"]
[FEN "4N2k/4PB1p/7P/B1p5/2P5/3q2Pp/1P3P1K/2r5 w - - 0 1"]

1. Bc3 Rxc3 2. Nc7

[Result "85"]
[FEN "1k6/3p4/1B6/4Pp1p/1p5R/1p4p1/pP3n2/K6n w - - 0 1"]

1. Rxh1 Nxh1 2. e6 dxe6 3. Bc7

[Result "86"]
[FEN "N3kb2/pq4p1/4B1P1/1p1P2B1/p7/3P4/2P5/2K5 w - - 0 1"]

1. Bf7 Kd7 2. Be6 Kd6 3. Bf4 Kc5 4. Be3 Kb4 5. Bd2 Ka3 6. Kb1

[Result "87"]
[FEN "8/1B3b1p/7P/p2p4/P2pp1kp/Q7/1N1Pq2P/7K w - - 0 1"]

1. Qh3

[Result "88"]
[FEN "1B2b2k/2N1qr2/4n2p/4p1PQ/1r2N3/1p6/7P/2KB4 w - - 0 1"]

1. Nd5 Rc4 2. Kb1 Rc1 3. Kb2 Rf2 4. Nf2 Rb1 5. Kb1 Qh7 6. g6 Bg6 7. Bc2 bxc2

8. Kc1 Bxh5 9. Be5 Ng7 10. Ne7

[Result "89"]
[FEN "2k4N/Q1np4/2p2Bpp/1p1P4/pPP1p2P/P7/7q/1K6 w - - 0 1"]

1. Nf7 Qg3 2. Qxc7 {win}

[Result "90"]
[FEN "8/4nk2/1p3p2/2rp2pp/1P1R1N1P/6P1/3KPP2/8 b - - 0 1"]

{avoid 1... Rb5}

[Result "91"]
[FEN "5BK1/5p1N/5Pp1/6Pk/8/1b6/8/7q b - - 0 1"]

1... Qa8 2.Kg7 Qd5 {or Qg2 and next Qxg5}

[Result "92"]
[FEN "2b5/1pr4p/3bp1pk/1p6/1PpN2PP/K1P1n3/P3N1R1/3R4 w - - 0 1"]

1. Nxb5 Nxd1 2. Nd6 b5 3. g5 Kh5 4. Nxc8 Rxc8 5. Nf4 Kxh4 6. Nxg6

[Result "93"]
[FEN "8/1p1pNpbk/q2P4/p3p2K/PP2N3/4P1P1/3P4/8 w - - 0 1"]

1. b5 Qb6 2. Nc8

[Result "94"]
[FEN "1rr5/6pk/7p/8/8/7P/1Pb1RRPK/8 b - - 0 1"]

{avoid Rxb2}

[Result "95"]
[FEN "6Q1/8/8/8/8/7k/ppp1p3/brrbK3 w - - 0 1"]

1. Qg1 {win}

[Result "96"]
[FEN "1B1K1k2/4N2p/3pP1pP/6p1/p7/3N2b1/2r2p2/8 w - - 0 1"]

1. Nc6 {win}

[Result "97"]
[FEN "8/4Pr1N/8/6PN/8/3K1ppp/4prkb/4Bbnn w - - 0 1"]

1. Nf8 {win}

[Result "98"]
[FEN "8/b7/3p2b1/5p1n/5Pk1/4P1p1/B5P1/R4K2 w - - 0 1"]

1. Ke2

[Result "99"]
[FEN "5K2/8/5B2/p7/8/p4p2/pn1PpPp1/kb2R3 w - - 0 1"]

1. Bh8 a4 2. Kg7 {win}

[Result "100"]
[FEN "3rqQ2/3ppppp/7k/R7/8/8/1PPP2K1/8 w - - 0 1"]

1. Ra3
[/pgn]

The authors of studies selected to the "IQ" test:

by YACPDB:

Blathy Otto - 3, 12, 13
Benko Pal - 16, 75
Hasek Josef - 22, 28
Gurvich Abram - 23
Kasparyan Genrikh - 24
Neghina Mihai - 27
Grasemann Herbert - 37
Popov Georgy & Hanyan Aleksei - 39 (part of study)
Rudolph William - 46
Troitzky Aleksei - 57
Reti Richard - 58
Matous Mario - 60
Behting Carl - 62
Klyatskin Mikhail - 66
Kubbel Karl - 69
Novomesky Daniel - 73
Lazard Frederic - 74
Marwitz Jan - 79
Lamford Paul - 82
Simkhovich Froim - 86

by other sources:

Solovyov Y. - 6
Babic M. - 10
Neghina Mihai - 11, 31, 35 (based on study), 84, 87, 89, 92
Simkhovich Froim - 20
van Breukelen Gijs - 36
Hoch Yehuda & Aloni Hillel - 55
Troitzky Aleksei - 59
Smyslov Vasily - 67
Bondarenko F. & Kuznetsov A. - 68
Surya Sekhar Ganguly - 81
Stavrietsky Aleksandr - 88
Kazantsev A. - 93
Ryabinin Nikolaj - 96
Neghina Mihai & Rusz Arpad- 97
Kamody Mario & Neghina Mihai - 98
Fekete Zoltan - 99 (part of study)

lech wrote: ↑Sat May 09, 2020 2:46 pm The "IQ" test is a very important part of my project (Sting) and doesn't contain middle-game tactical positions and technical endgames.
Here are positions dedicated to all engines to test so-called by me "quasi-intelligent" their abilities.

Don't use such external tricks like: rule-50 changing, null-move disabling, special parameters and others.
The external tools like: MultiPV, tablebases, "backward-forward" and "Monte Carlo" are not welcome too.

"WIN" means the correct solution and some non-zero score.
Don't do the test in a machine way. Test and analyze each of items separately!

[pgn]
[Result "1"]
[FEN "rk6/p1r3p1/P3B1Kp/1p2B3/8/8/8/8 w - - 0 1"]

1. Bd7 {win}

[Result "2"]
[FEN "7k/6rp/6pN/1r4P1/3B4/8/8/K7 b - - 0 1"]

1... Rxg5

[Result "3"]
[FEN "1B1k4/3p4/1Kp5/PpP2p2/1PqP1P2/8/1P6/8 w - - 0 1"]

1. a6 {win}

[Result "4"]
[FEN "3N2r1/2K1p3/4Pk2/8/Bp5b/8/2P5/8 b - - 0 1"]

1... Bg3 2. Kd7 {or Kc8} Rxd8

[Result "5"]
[FEN "8/7p/5P1k/1p5P/5p2/2p1p3/P1P1P1P1/1K3Nb1 w - - 0 1"]

1. Ng3

[Result "6"]
[FEN "6q1/PpB5/k7/P6K/6n1/1P4p1/5p2/1B3N1N w - - 0 1"]

1. a8Q {or a8R}

[Result "7"]
[FEN "6k1/6p1/4Rb1p/p7/rp2P1N1/2P3P1/1P5P/6K1 b - - 0 1"]

1... Bxc3

[Result "8"]
[FEN "8/8/p2k1p2/1p1p3p/1P1P3p/P3NPP1/5K2/1b6 w - - 0 1"]

1. Ng2

[Result "9"]
[FEN "2k5/p7/Pp1p1b2/1P1P1p2/2P2P1p/3K3P/5B2/8 w - - 0 1"]

1. c5

[Result "10"]
[FEN "1n6/Pp1p1p1p/1P1P1P1P/4K3/2p5/p7/rpp1P3/qkb1R3 w - - 0 1"]

1. axb8N {win}

[Result "11"]
[FEN "1N4K1/1pp1p3/7k/2r3pP/p2pp1P1/P6N/8/2B5 w - - 0 1"]

1. Nc6

[Result "12"]
[FEN "5K2/k4p1p/5p1p/1p3p2/bP6/1p6/1P5p/7B w - - 0 1"]

1. Ke8 {or Ke7 win}

[Result "13"]
[FEN "k1b5/1p1p1p1p/1PpPpP2/2B5/8/2p1p2P/2PbP3/3K4 w - - 0 1"]

1. Bd4 {win}

[Result "14"]
[FEN "8/8/8/8/1kB1q3/8/1PRb4/1K6 b - - 0 1"]

1... Qh1 2. Ka2 Qa8 3.Kb1 Qe4 {or other way to get the start position for

white: 8/8/8/8/1kB1q3/8/1PRb4/1K6 w - - 0 1}

[Result "15"]
[FEN "8/2N4r/1p3pkp/8/5K1p/2P4N/P3Bn2/8 w - - 0 1"]

1. Bh5

[Result "16"]
[FEN "4k1rr/1R1R3p/8/8/8/2K5/7P/8 w k - 0 1"]

1. Rd2

[Result "17"]
[FEN "5k2/4bp2/2B3p1/1P4p1/3R4/3P2PP/2r2PK1/8 b - - 0 1"]

1... Rxf2

[Result "18"]
[FEN "1b6/2p5/1kB5/1PN5/8/3K4/8/q7 w - - 0 1"]

1. Nb3

[Result "19"]
[FEN "N7/8/2KQ2rp/6k1/3p3p/2p4P/4PP2/5N2 w - - 0 1"]

1. f4

[Result "20"]
[FEN "2br4/r2pp3/8/1p1p1kN1/pP1P4/2P3R1/PP3PP1/2K5 w - - 0 1"]

1. Nf7 Re8 2. Nd6

[Result "21"]
[FEN "8/8/4B3/6p1/7k/8/4pPKP/8 w - - 0 1"]

1. Bg4

[Result "22"]
[FEN "r7/7k/5R2/p3p3/Pp1pPp2/1PpP1Pp1/K1P3P1/8 w - - 0 1"]

1. Kb1 Kg7 {or 1... Rh8 2. Rf8} 2. Rh6

[Result "23"]
[FEN "1K3kB1/8/6p1/7R/8/4b3/8/6n1 w - - 0 1"]

1. Rh8 Kg7 2. Bh7

[Result "24"]
[FEN "8/8/R7/1b4k1/5p2/1B3r2/7P/7K w - - 0 1"]

1. h4 Kxh4 2. Rh6 Kg5 3. Rh5

[Result "25"]
[FEN "7Q/4p3/4p3/p1p1P3/Pp2P3/3Kp3/p1PbP3/kN6 w - - 0 1"]

1. Na3 bxa3 2. Qh1 Kb2 3. Qa1 Kxa1 4. c4

[Result "26"]
[FEN "7r/K7/5k1n/p3p3/Pp1pPp1p/1PpP1PpP/2P3P1/N1RR1B2 b - - 0 1"]

{win}

[Result "27"]
[FEN "q7/b1p5/kp1p4/p2PN3/PPP5/1K6/8/5B2 w - - 0 1"]

1. c5 Kb7 2. Ba6 {win}

[Result "28"]
[FEN "1k1n4/1p1b1p2/1Bp1pPp1/1PP1P3/8/6P1/8/1K6 w - - 0 1"]

1. Bc7 {win}

[Result "29"]
[FEN "4q1kr/p6p/1prQPppB/4n3/4P3/2P5/PP2B2P/R5K1 w - - 0 1"]

1. Qxe5 {win}

[Result "30"]
[FEN "q1b4n/1p1pKp2/1p1p1Pp1/1P1P2Pp/2P4P/8/7R/1N1k4 w - - 0 1"]

1. Ra2 {win}

[Result "31"]
[FEN "3k4/2pq3p/pp5R/4P3/P6P/2PN4/1PN3K1/8 w - - 0 1"]

1. Nd4 {win}

[Result "32"]
[FEN "8/7p/6pP/p4pP1/3BpP2/p1KpP3/pn1N4/k7 w - - 0 1"]

1. Bh8 {win}

[Result "33"]
[FEN "8/6p1/p7/rp1K2p1/kb3pP1/2p2p1b/P1Np1P2/3N2R1 w - - 0 1"]

1. Ke6 {or Ke4 win}

[Result "34"]
[FEN "B7/p1p5/k2p4/p3p3/P1Nb1p2/6p1/7p/4K3 w - - 0 1"]

{Ke1->h3->c8}

[Result "35"]
[FEN "1qN5/b1pB4/1pP2k2/pP3P2/P1P5/8/8/K7 w - - 0 1"]

{Ka1->h5->d8}

[Result "36"]
[FEN "8/3P3k/n2K3p/2p3n1/1b4N1/2p1p1P1/8/3B4 w - - 0 1"]

1. Nf6

[Result "37"]
[FEN "8/5K2/3p3p/3p3P/pp1P4/rkb1R3/p1p3P1/n1B2B2 w - - 0 1"]

1. Rd3 {win}

[Result "38"]
[FEN "6bn/p4p1k/rp3Pp1/rp2BBP1/1p6/pK6/P2P4/8 w - - 0 1"]

1. Bc8 {win}

[Result "39"]
[FEN "qn6/b1Kp3p/p1pB3p/p7/P1NkP3/2pP4/2B5/8 w - - 0 1"]

1. Bf4 {or Kc8 - win}

[Result "40"]
[FEN "8/P7/4k3/8/5P2/4Bq2/5P2/5K2 b - - 0 1"]

1... Kf5

[Result "41"]
[FEN "8/6kP/1p6/p7/Pr6/K2B4/8/8 b - - 0 1"]

{Rb4->h4 and next Kg7->e5}

[Result "42"]
[FEN "8/8/2b1N3/5p2/3B4/2K5/6kp/R7 w - - 0 1"]

1. Rh1

[Result "43"]
[FEN "8/8/4kpp1/3p1b2/p6P/2B5/6P1/6K1 b - - 0 1"]

1... Bh3

[Result "44"]
[FEN "5rk1/5ppp/p1Q1p3/1R6/q7/4b1P1/P2RPP1P/6K1 w - - 0 1"]

1. Rd8 {win}

[Result "45"]
[FEN "r7/1b1r4/k1p1p1p1/1p1pPpPp/p1PP1P1P/PP1K4/8/4Q3 w - - 0 1"]

1. Qa5

[Result "46"]
[FEN "3B4/1r2p3/r2p1p2/bkp1P1p1/1p1P1PPp/p1P4P/PPB1K3/8 w - - 0 1"]

1. Ba4

[Result "47"]
[FEN "2k5/2p5/1q1p4/pPpPp1pp/N1P1Pp2/P4PbP/KQ4P1/8 w - - 0 1"]

{avoid Nxb6}

[Result "48"]
[FEN "1r6/4k3/r2p2p1/2pR1p1p/2P1pP1P/pPK1P1P1/P7/1B6 b - - 0 1"]

1... Rxb3

[Result "49"]
[FEN "8/5k2/6p1/4BP1p/6p1/p1p3PP/6P1/1n2K2R b K - 0 1"]

1... a2 2. fxg6 Kg8

[Result "50"]
[FEN "8/3k1b1r/2p1p1p1/rpPpPpPp/p2P1P1P/P2K4/8/4B3 w - - 0 1"]

1. Bb4

[Result "51"]
[FEN "7b/p1p1p3/P1PpPp2/2nP1kpr/5P1p/p3KBPP/P7/8 w - - 0 1"]

1. Be4

[Result "52"]
[FEN "7r/p1p1p1pk/3pPp1p/2pP1PP1/P1P4P/1K6/P6B/8 w - - 0 1"]

1. g6 Kg8 2. a5 a6 3. Bxd6 cxd6 4. h5 {or 2. Bxd6 cxd6 3. h5}

[Result "53"]
[FEN "8/1p1q1k2/1Pp5/p1Pp4/P2Pp1p1/4PpPp/1N3P1P/3B2K1 w - - 0 1"]

1. Bb3 Qc8 2. Nd1 Qa8 3. Bc4

[Result "54"]
[FEN "8/8/2pk4/8/p1p3B1/PpP5/1P6/r1NK4 w - - 0 1"]

1. Bf5 Ra2 2. Nxa2 bxa2 3. Kc1 a1Q 4. Bb1

[Result "55"]
[FEN "1R3b2/5ppQ/6Pp/6PP/R6P/P7/7K/2q1k3 w - - 0 1"]

1. Rb1 Qxb1 2. gxf7

[Result "56"]
[FEN "Kn6/8/8/3R2PB/8/2p2NP1/1q6/2k5 w - - 0 1"]

1. Rd1

[Result "57"]
[FEN "1B3B1B/2B5/p6B/8/8/8/8/1k1K4 w - - 0 1"]

1. Bce5

[Result "58"]
[FEN "4kr2/5p1K/3p1Q2/1p4P1/4P3/1PP5/7b/8 w - - 0 1"]

1. Kh6 {win}

[Result "59"]
[FEN "6R1/8/2pB3k/2P4p/5p1q/5P2/4P1K1/8 w - - 0 1"]

1. Bf8 {win}

[Result "60"]
[FEN "n2Bqk2/5p1p/Q4KP1/p7/8/8/8/8 w - - 0 1"]

1. Qc8 Kg8 2. Bc7 {win}

[Result "61"]
[FEN "8/5p2/8/8/p7/rpK4p/1p3ppr/bQ1N1bqk w - - 0 1"]

1. Kb4 {or Kd4 win}

[Result "62"]
[FEN "8/8/7p/3KNN1k/2p4p/8/3P2p1/8 w - - 0 1"]

1. Kc6

[Result "63"]
[FEN "1R6/pPk1r3/2p5/K7/8/2B1b3/8/8 w - - 0 1"]

1. Ka6

[Result "64"]
[FEN "8/p7/qkpN1p2/8/1B1P4/PP3K2/5P2/8 w - - 0 1"]

1. Ba5 {win}

[Result "65"]
[FEN "2N5/p7/P7/8/1KPp1p1p/3p1Bpp/3P2rq/R5bk w - - 0 1"]

1. Nb6 {win}

[Result "66"]
[FEN "5kN1/3p1q2/5P2/5PP1/2pK4/1p1R4/1P6/8 w - - 0 1"]

1. Rxb3

[Result "67"]
[FEN "2b1rk2/5p2/p1P5/2p2P2/2p5/7B/P7/2KR4 w - - 0 1"]

1. f6

[Result "68"]
[FEN "2r5/prkpR1p1/2p1ppK1/P1p1N1B1/P1P1P3/8/8/8 w - - 0 1"]

1. Bf4

[Result "69"]
[FEN "rk1b4/p2p2p1/1P6/2R2P2/8/2K5/8/5B2 w - - 0 1"]

1. Rc8 {win}

[Result "70"]
[FEN "3k4/4pp2/n2n4/5BN1/3N4/b7/4K3/8 w - - 0 1"]

1. Nxf7

[Result "71"]
[FEN "4b3/8/1P6/3K4/6p1/5pP1/5P1B/7k w - - 0 1"]

1. b7 Bb5 2. b8R

[Result "72"]
[FEN "8/5pKN/5Pp1/5kP1/8/Bb6/8/7q w - - 0 1"]

1. Bc5 {or any move} Qxh7+

[Result "73"]
[FEN "8/p5p1/1pP3p1/p5p1/k3p3/4p3/K7/8 w - - 0 1"]

1. c7 {win}

[Result "74"]
[FEN "q7/8/2p5/B2p2pp/5pp1/2N3k1/6P1/7K w - - 0 1"]

1. Ne4 Kh4 2. Ng3 fxg3 3. Bb6

[Result "75"]
[FEN "q7/7R/k7/1p6/1p6/1P2B3/7K/8 w - - 0 1"]

1. Bd4 {win}

[Result "76"]
[FEN "1q1r3k/3P1pp1/ppBR1n1p/4Q2P/P4P2/8/5PK1/8 w - - 0 1"]

1. Rxf6

[Result "77"]
[FEN "1r3q1k/2N2P1p/6pQ/4p3/7p/n6P/3B4/7K w - - 0 1"]

1. Qf4 {win}

[Result "78"]
[FEN "5nr1/2Pp2pk/3Pp1p1/4P1P1/6P1/5K2/8/7n w - - 0 1"]

1. c8N

[Result "79"]
[FEN "2K3k1/1p6/R3p1p1/1rB1P1P1/8/8/1Pb5/8 w - - 0 1"]

1. Rc6

[Result "80"]
[FEN "4q3/2r1r2p/3P3P/1p6/kP6/Pp6/1P6/KB2R3 w - - 0 1"]

1. Rxe7 Qxe7 {or 1... Rxe7 2. dxe7} 2. dxc7

[Result "81"]
[FEN "3k4/8/7p/2p1p1pP/1pPpPpP1/1P1P1P2/N7/2K5 w - - 0 1"]

{Na2->h4}

[Result "82"]
[FEN "8/8/8/1k3p2/p1p1pPp1/PpPpP1Pp/1P1P3P/QNK2NRR w - - 0 1"]

{win}

[Result "83"]
[FEN "4b1k1/P4pPp/1R3P1P/2r5/8/1P6/1K6/8 w - - 0 1"]

1. a8B

[Result "84"]
[FEN "4N2k/4PB1p/7P/B1p5/2P5/3q2Pp/1P3P1K/2r5 w - - 0 1"]

1. Bc3 Rxc3 2. Nc7

[Result "85"]
[FEN "1k6/3p4/1B6/4Pp1p/1p5R/1p4p1/pP3n2/K6n w - - 0 1"]

1. Rxh1 Nxh1 2. e6 dxe6 3. Bc7

[Result "86"]
[FEN "N3kb2/pq4p1/4B1P1/1p1P2B1/p7/3P4/2P5/2K5 w - - 0 1"]

1. Bf7 Kd7 2. Be6 Kd6 3. Bf4 Kc5 4. Be3 Kb4 5. Bd2 Ka3 6. Kb1

[Result "87"]
[FEN "8/1B3b1p/7P/p2p4/P2pp1kp/Q7/1N1Pq2P/7K w - - 0 1"]

1. Qh3

[Result "88"]
[FEN "1B2b2k/2N1qr2/4n2p/4p1PQ/1r2N3/1p6/7P/2KB4 w - - 0 1"]

1. Nd5 Rc4 2. Kb1 Rc1 3. Kb2 Rf2 4. Nf2 Rb1 5. Kb1 Qh7 6. g6 Bg6 7. Bc2 bxc2

8. Kc1 Bxh5 9. Be5 Ng7 10. Ne7

[Result "89"]
[FEN "2k4N/Q1np4/2p2Bpp/1p1P4/pPP1p2P/P7/7q/1K6 w - - 0 1"]

1. Nf7 Qg3 2. Qxc7 {win}

[Result "90"]
[FEN "8/4nk2/1p3p2/2rp2pp/1P1R1N1P/6P1/3KPP2/8 b - - 0 1"]

{avoid 1... Rb5}

[Result "91"]
[FEN "5BK1/5p1N/5Pp1/6Pk/8/1b6/8/7q b - - 0 1"]

1... Qa8 2.Kg7 Qd5 {or Qg2 and next Qxg5}

[Result "92"]
[FEN "2b5/1pr4p/3bp1pk/1p6/1PpN2PP/K1P1n3/P3N1R1/3R4 w - - 0 1"]

1. Nxb5 Nxd1 2. Nd6 b5 3. g5 Kh5 4. Nxc8 Rxc8 5. Nf4 Kxh4 6. Nxg6

[Result "93"]
[FEN "8/1p1pNpbk/q2P4/p3p2K/PP2N3/4P1P1/3P4/8 w - - 0 1"]

1. b5 Qb6 2. Nc8

[Result "94"]
[FEN "1rr5/6pk/7p/8/8/7P/1Pb1RRPK/8 b - - 0 1"]

{avoid Rxb2}

[Result "95"]
[FEN "6Q1/8/8/8/8/7k/ppp1p3/brrbK3 w - - 0 1"]

1. Qg1 {win}

[Result "96"]
[FEN "1B1K1k2/4N2p/3pP1pP/6p1/p7/3N2b1/2r2p2/8 w - - 0 1"]

1. Nc6 {win}

[Result "97"]
[FEN "8/4Pr1N/8/6PN/8/3K1ppp/4prkb/4Bbnn w - - 0 1"]

1. Nf8 {win}

[Result "98"]
[FEN "8/b7/3p2b1/5p1n/5Pk1/4P1p1/B5P1/R4K2 w - - 0 1"]

1. Ke2

[Result "99"]
[FEN "5K2/8/5B2/p7/8/p4p2/pn1PpPp1/kb2R3 w - - 0 1"]

1. Bh8 a4 2. Kg7 {win}

[Result "100"]
[FEN "3rqQ2/3ppppp/7k/R7/8/8/1PPP2K1/8 w - - 0 1"]

1. Ra3
[/pgn]

The authors of studies selected to the "IQ" test:

I learned about your first position from Bernhard Bauer here:

http://www.talkchess.com/forum3/viewtop ... 10#p753058

I don't know if he created the position. I did not find any earlier appearance of this position, but I didn't search carefully.

Hi Louis,

It's a part of this Study:
[pgn][Event "?"]
[Site "?"]
[Date "1832.??.??"]
[Round "?"]
[White "Mendheim=J"]
[Black "?"]
[Result "1-0"]
[SetUp "1"]
[FEN "rkr5/p5p1/Pp4Kp/8/3B4/1B6/8/8 w - - 0 1"]
[PlyCount "13"]
[EventDate "1832.??.??"]

1. Be5+ Rc7 2. Be6 b5 3. Bd7 b4 4. Kf7 b3 5. Ke8 {<or>}(5.
Ke7) 5... b2 6. Kd8 b1=Q 7. Bxc7# 1-0
[/pgn]

If it is so important and I remember good, I am the autor of items: 2, 4, 40, 41, 100 only and I am still alive.

Paloma wrote: ↑Sun May 10, 2020 1:47 am Hi Louis,

It's a part of this Study:
[pgn][Event "?"]
[Site "?"]
[Date "1832.??.??"]
[Round "?"]
[White "Mendheim=J"]
[Black "?"]
[Result "1-0"]
[SetUp "1"]
[FEN "rkr5/p5p1/Pp4Kp/8/3B4/1B6/8/8 w - - 0 1"]
[PlyCount "13"]
[EventDate "1832.??.??"]

1. Be5+ Rc7 2. Be6 b5 3. Bd7 b4 4. Kf7 b3 5. Ke8 {<or>}(5.
Ke7) 5... b2 6. Kd8 b1=Q 7. Bxc7# 1-0
[/pgn]

Thanks! So it is very old.

Hello:

zullil wrote: ↑Sun May 10, 2020 12:12 pm

Paloma wrote: ↑Sun May 10, 2020 1:47 am Hi Louis,

It's a part of this Study:
[pgn][Event "?"]
[Site "?"]
[Date "1832.??.??"]
[Round "?"]
[White "Mendheim=J"]
[Black "?"]
[Result "1-0"]
[SetUp "1"]
[FEN "rkr5/p5p1/Pp4Kp/8/3B4/1B6/8/8 w - - 0 1"]
[PlyCount "13"]
[EventDate "1832.??.??"]

1. Be5+ Rc7 2. Be6 b5 3. Bd7 b4 4. Kf7 b3 5. Ke8 {<or>}(5.
Ke7) 5... b2 6. Kd8 b1=Q 7. Bxc7# 1-0
[/pgn]

Thanks! So it is very old.

YACPDB lists Mendheim's problem in its number 311979:

https://www.yacpdb.org/#311979

YACPDB wrote:Mendheim, Julius
The New York Clipper, 25 May 1867 (E579)
1.Be5+! Rc7 2.Be6 ~ 3.Bd7 ~ 4.Kf7 ~
5.Ke8 ~ 6.Kd8 ~ 7.B×c7#
5.Ke7 ~ 6.Kd8 ~ 7.B×c7#

It is true that the problem appeared in The New York Clipper of 25th May, 1867 (page 58, Enigma No. 579, hence 'E579' from YACPDB):

The New York Clipper, 25 May 1867

The New York Clipper wrote:Enigma No. 579.
BY MENDHEIM.

K at his Kt 6, B Q4, B Q Kt 3, P Q R 6th.
k at Q Kt sq, r Q R sq, r Q B sq, p Q R 2, p Q Kt 3, p K Kt 2, p R R 3d.

White to play and give mate in seven moves.

But I read somewhere at TalkChess that this problem is dated from 1832. I found that source: Aufgaben für Schachspieler nebst auflösungen ('Tasks for chess players with resolutions'), 61st task:

Aufgaben für Schachspieler nebst auflösungen (1832)

Book preview

Aufgaben für Schachspieler nebst auflösungen (1832) wrote: Stellung der Steine.
Weiß. K-g6. L-b3, d4. b-a6.
Schwartz. K-b8. T-a8, c8. b-a7, b6, g7, h6.
Der Weiße macht in 7 Zügen matt.

Problem without diagram at page 14 and solution at page 44.

Other curious fact is the presence of descriptive notation in 1867 while there is a kind of algebraic notation in 1832 (same in 1814, please see the off-topic problem source below).

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

Just a bit off-topic, I found a fun problem from the same author in his book Taschenbuch für Schachfreunde ('Paperback for chess fans') of 1814.

Taschenbuch für Schachfreunde (1814)

Book preview

Problem 27 (pages 53 and 54). Condition: checkmate in a2 square in 12 moves only moving the white knights.

[pgn][Event "?"]
[Site "?"]
[Date "1814.??.??"]
[Round "?"]
[White "Mendheim, Juluis"]
[Black "?"]
[Result "1-0"]
[SetUp "1"]
[FEN "3kn1r1/b2p2p1/1pR1pn2/N4p2/1N1K2b1/B7/1P1P1P1R/rB1q2Q1 w - - 0 1"]
[PlyCount "25"]
[EventDate "1814.??.??"]

1. Nb7+ Ke7 2. Nd5+ Kf7 3. Nd8+ Kg6 4. Ne7+ Kg5 5. Nf7+ Kf4 6. Ng6+ Kf3 7. Nfe5+ Ke2 8. Nf4+ Kd2 9. Nc4+ Kc1 10. Nd3+ Kb1 11. Nd2+ Ka2 12. Nb4# 1-0[/pgn]

What a knights tour!

It is not the shortest checkmate but I consider the knights checks theme entertaining.

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

I hope no typos.

Regards from Spain.

Ajedrecista.

Ajedrecista wrote: ↑Sun May 10, 2020 1:10 pm Problem 27 (pages 53 and 54). Condition: checkmate in a2 square in 12 moves only moving the white knights.

[pgn][Event "?"]
[Site "?"]
[Date "1814.??.??"]
[Round "?"]
[White "Mendheim, Juluis"]
[Black "?"]
[Result "1-0"]
[SetUp "1"]
[FEN "3kn1r1/b2p2p1/1pR1pn2/N4p2/1N1K2b1/B7/1P1P1P1R/rB1q2Q1 w - - 0 1"]
[PlyCount "25"]
[EventDate "1814.??.??"]

1. Nb7+ Ke7 2. Nd5+ Kf7 3. Nd8+ Kg6 4. Ne7+ Kg5 5. Nf7+ Kf4 6. Ng6+ Kf3 7. Nfe5+ Ke2 8. Nf4+ Kd2 9. Nc4+ Kc1 10. Nd3+ Kb1 11. Nd2+ Ka2 12. Nb4# 1-0[/pgn]

What a knights tour!

It is not the shortest checkmate but I consider the knights checks theme entertaining.

Thanks for the research about the author. If theme wasn't moving knights only, White could mate with 6.Qg3# instead of Ng6+ already, but yes, it's really beautiful for the eye of the human player.

Indeed it seems to be much better to save the first item of the "IQ" test in an original way as study. Thanks!

[pgn]
[Result "1"]
[FEN "rkr5/p5p1/Pp4Kp/8/3B4/1B6/8/8 w - - 0 1"]

1. Be5 {win}

[Result "2"]
[FEN "7k/6rp/6pN/1r4P1/3B4/8/8/K7 b - - 0 1"]

1... Rxg5

[Result "3"]
[FEN "1B1k4/3p4/1Kp5/PpP2p2/1PqP1P2/8/1P6/8 w - - 0 1"]

1. a6 {win}

[Result "4"]
[FEN "3N2r1/2K1p3/4Pk2/8/Bp5b/8/2P5/8 b - - 0 1"]

1... Bg3 2. Kd7 {or Kc8} Rxd8

[Result "5"]
[FEN "8/7p/5P1k/1p5P/5p2/2p1p3/P1P1P1P1/1K3Nb1 w - - 0 1"]

1. Ng3

[Result "6"]
[FEN "6q1/PpB5/k7/P6K/6n1/1P4p1/5p2/1B3N1N w - - 0 1"]

1. a8Q {or a8R}

[Result "7"]
[FEN "6k1/6p1/4Rb1p/p7/rp2P1N1/2P3P1/1P5P/6K1 b - - 0 1"]

1... Bxc3

[Result "8"]
[FEN "8/8/p2k1p2/1p1p3p/1P1P3p/P3NPP1/5K2/1b6 w - - 0 1"]

1. Ng2

[Result "9"]
[FEN "2k5/p7/Pp1p1b2/1P1P1p2/2P2P1p/3K3P/5B2/8 w - - 0 1"]

1. c5

[Result "10"]
[FEN "1n6/Pp1p1p1p/1P1P1P1P/4K3/2p5/p7/rpp1P3/qkb1R3 w - - 0 1"]

1. axb8N {win}

[Result "11"]
[FEN "1N4K1/1pp1p3/7k/2r3pP/p2pp1P1/P6N/8/2B5 w - - 0 1"]

1. Nc6

[Result "12"]
[FEN "5K2/k4p1p/5p1p/1p3p2/bP6/1p6/1P5p/7B w - - 0 1"]

1. Ke8 {or Ke7 win}

[Result "13"]
[FEN "k1b5/1p1p1p1p/1PpPpP2/2B5/8/2p1p2P/2PbP3/3K4 w - - 0 1"]

1. Bd4 {win}

[Result "14"]
[FEN "8/8/8/8/1kB1q3/8/1PRb4/1K6 b - - 0 1"]

1... Qh1 2. Ka2 Qa8 3.Kb1 Qe4 {or other way to get the start position for white: 8/8/8/8/1kB1q3/8/1PRb4/1K6 w - - 0 1}

[Result "15"]
[FEN "8/2N4r/1p3pkp/8/5K1p/2P4N/P3Bn2/8 w - - 0 1"]

1. Bh5

[Result "16"]
[FEN "4k1rr/1R1R3p/8/8/8/2K5/7P/8 w k - 0 1"]

1. Rd2

[Result "17"]
[FEN "5k2/4bp2/2B3p1/1P4p1/3R4/3P2PP/2r2PK1/8 b - - 0 1"]

1... Rxf2

[Result "18"]
[FEN "1b6/2p5/1kB5/1PN5/8/3K4/8/q7 w - - 0 1"]

1. Nb3

[Result "19"]
[FEN "N7/8/2KQ2rp/6k1/3p3p/2p4P/4PP2/5N2 w - - 0 1"]

1. f4

[Result "20"]
[FEN "2br4/r2pp3/8/1p1p1kN1/pP1P4/2P3R1/PP3PP1/2K5 w - - 0 1"]

1. Nf7 Re8 2. Nd6

[Result "21"]
[FEN "8/8/4B3/6p1/7k/8/4pPKP/8 w - - 0 1"]

1. Bg4

[Result "22"]
[FEN "r7/7k/5R2/p3p3/Pp1pPp2/1PpP1Pp1/K1P3P1/8 w - - 0 1"]

1. Kb1 Kg7 {or 1... Rh8 2. Rf8} 2. Rh6

[Result "23"]
[FEN "1K3kB1/8/6p1/7R/8/4b3/8/6n1 w - - 0 1"]

1. Rh8 Kg7 2. Bh7

[Result "24"]
[FEN "8/8/R7/1b4k1/5p2/1B3r2/7P/7K w - - 0 1"]

1. h4 Kxh4 2. Rh6 Kg5 3. Rh5

[Result "25"]
[FEN "7Q/4p3/4p3/p1p1P3/Pp2P3/3Kp3/p1PbP3/kN6 w - - 0 1"]

1. Na3 bxa3 2. Qh1 Kb2 3. Qa1 Kxa1 4. c4

[Result "26"]
[FEN "7r/K7/5k1n/p3p3/Pp1pPp1p/1PpP1PpP/2P3P1/N1RR1B2 b - - 0 1"]

{win}

[Result "27"]
[FEN "q7/b1p5/kp1p4/p2PN3/PPP5/1K6/8/5B2 w - - 0 1"]

1. c5 Kb7 2. Ba6 {win}

[Result "28"]
[FEN "1k1n4/1p1b1p2/1Bp1pPp1/1PP1P3/8/6P1/8/1K6 w - - 0 1"]

1. Bc7 {win}

[Result "29"]
[FEN "4q1kr/p6p/1prQPppB/4n3/4P3/2P5/PP2B2P/R5K1 w - - 0 1"]

1. Qxe5 {win}

[Result "30"]
[FEN "q1b4n/1p1pKp2/1p1p1Pp1/1P1P2Pp/2P4P/8/7R/1N1k4 w - - 0 1"]

1. Ra2 {win}

[Result "31"]
[FEN "3k4/2pq3p/pp5R/4P3/P6P/2PN4/1PN3K1/8 w - - 0 1"]

1. Nd4 {win}

[Result "32"]
[FEN "8/7p/6pP/p4pP1/3BpP2/p1KpP3/pn1N4/k7 w - - 0 1"]

1. Bh8 {win}

[Result "33"]
[FEN "8/6p1/p7/rp1K2p1/kb3pP1/2p2p1b/P1Np1P2/3N2R1 w - - 0 1"]

1. Ke6 {or Ke4 win}

[Result "34"]
[FEN "B7/p1p5/k2p4/p3p3/P1Nb1p2/6p1/7p/4K3 w - - 0 1"]

{Ke1->h3->c8}

[Result "35"]
[FEN "1qN5/b1pB4/1pP2k2/pP3P2/P1P5/8/8/K7 w - - 0 1"]

{Ka1->h5->d8}

[Result "36"]
[FEN "8/3P3k/n2K3p/2p3n1/1b4N1/2p1p1P1/8/3B4 w - - 0 1"]

1. Nf6

[Result "37"]
[FEN "8/5K2/3p3p/3p3P/pp1P4/rkb1R3/p1p3P1/n1B2B2 w - - 0 1"]

1. Rd3 {win}

[Result "38"]
[FEN "6bn/p4p1k/rp3Pp1/rp2BBP1/1p6/pK6/P2P4/8 w - - 0 1"]

1. Bc8 {win}

[Result "39"]
[FEN "qn6/b1Kp3p/p1pB3p/p7/P1NkP3/2pP4/2B5/8 w - - 0 1"]

1. Bf4 {or Kc8 - win}

[Result "40"]
[FEN "8/P7/4k3/8/5P2/4Bq2/5P2/5K2 b - - 0 1"]

1... Kf5

[Result "41"]
[FEN "8/6kP/1p6/p7/Pr6/K2B4/8/8 b - - 0 1"]

{Rb4->h4 and next Kg7->e5}

[Result "42"]
[FEN "8/8/2b1N3/5p2/3B4/2K5/6kp/R7 w - - 0 1"]

1. Rh1

[Result "43"]
[FEN "8/8/4kpp1/3p1b2/p6P/2B5/6P1/6K1 b - - 0 1"]

1... Bh3

[Result "44"]
[FEN "5rk1/5ppp/p1Q1p3/1R6/q7/4b1P1/P2RPP1P/6K1 w - - 0 1"]

1. Rd8 {win}

[Result "45"]
[FEN "r7/1b1r4/k1p1p1p1/1p1pPpPp/p1PP1P1P/PP1K4/8/4Q3 w - - 0 1"]

1. Qa5

[Result "46"]
[FEN "3B4/1r2p3/r2p1p2/bkp1P1p1/1p1P1PPp/p1P4P/PPB1K3/8 w - - 0 1"]

1. Ba4

[Result "47"]
[FEN "2k5/2p5/1q1p4/pPpPp1pp/N1P1Pp2/P4PbP/KQ4P1/8 w - - 0 1"]

{avoid Nxb6}

[Result "48"]
[FEN "1r6/4k3/r2p2p1/2pR1p1p/2P1pP1P/pPK1P1P1/P7/1B6 b - - 0 1"]

1... Rxb3

[Result "49"]
[FEN "8/5k2/6p1/4BP1p/6p1/p1p3PP/6P1/1n2K2R b K - 0 1"]

1... a2 2. fxg6 Kg8

[Result "50"]
[FEN "8/3k1b1r/2p1p1p1/rpPpPpPp/p2P1P1P/P2K4/8/4B3 w - - 0 1"]

1. Bb4

[Result "51"]
[FEN "7b/p1p1p3/P1PpPp2/2nP1kpr/5P1p/p3KBPP/P7/8 w - - 0 1"]

1. Be4

[Result "52"]
[FEN "7r/p1p1p1pk/3pPp1p/2pP1PP1/P1P4P/1K6/P6B/8 w - - 0 1"]

1. g6 Kg8 2. a5 a6 3. Bxd6 cxd6 4. h5 {or 2. Bxd6 cxd6 3. h5}

[Result "53"]
[FEN "8/1p1q1k2/1Pp5/p1Pp4/P2Pp1p1/4PpPp/1N3P1P/3B2K1 w - - 0 1"]

1. Bb3 Qc8 2. Nd1 Qa8 3. Bc4

[Result "54"]
[FEN "8/8/2pk4/8/p1p3B1/PpP5/1P6/r1NK4 w - - 0 1"]

1. Bf5 Ra2 2. Nxa2 bxa2 3. Kc1 a1Q 4. Bb1

[Result "55"]
[FEN "1R3b2/5ppQ/6Pp/6PP/R6P/P7/7K/2q1k3 w - - 0 1"]

1. Rb1 Qxb1 2. gxf7

[Result "56"]
[FEN "Kn6/8/8/3R2PB/8/2p2NP1/1q6/2k5 w - - 0 1"]

1. Rd1

[Result "57"]
[FEN "1B3B1B/2B5/p6B/8/8/8/8/1k1K4 w - - 0 1"]

1. Bce5

[Result "58"]
[FEN "4kr2/5p1K/3p1Q2/1p4P1/4P3/1PP5/7b/8 w - - 0 1"]

1. Kh6 {win}

[Result "59"]
[FEN "6R1/8/2pB3k/2P4p/5p1q/5P2/4P1K1/8 w - - 0 1"]

1. Bf8 {win}

[Result "60"]
[FEN "n2Bqk2/5p1p/Q4KP1/p7/8/8/8/8 w - - 0 1"]

1. Qc8 Kg8 2. Bc7 {win}

[Result "61"]
[FEN "8/5p2/8/8/p7/rpK4p/1p3ppr/bQ1N1bqk w - - 0 1"]

1. Kb4 {or Kd4 win}

[Result "62"]
[FEN "8/8/7p/3KNN1k/2p4p/8/3P2p1/8 w - - 0 1"]

1. Kc6

[Result "63"]
[FEN "1R6/pPk1r3/2p5/K7/8/2B1b3/8/8 w - - 0 1"]

1. Ka6

[Result "64"]
[FEN "8/p7/qkpN1p2/8/1B1P4/PP3K2/5P2/8 w - - 0 1"]

1. Ba5 {win}

[Result "65"]
[FEN "2N5/p7/P7/8/1KPp1p1p/3p1Bpp/3P2rq/R5bk w - - 0 1"]

1. Nb6 {win}

[Result "66"]
[FEN "5kN1/3p1q2/5P2/5PP1/2pK4/1p1R4/1P6/8 w - - 0 1"]

1. Rxb3

[Result "67"]
[FEN "2b1rk2/5p2/p1P5/2p2P2/2p5/7B/P7/2KR4 w - - 0 1"]

1. f6

[Result "68"]
[FEN "2r5/prkpR1p1/2p1ppK1/P1p1N1B1/P1P1P3/8/8/8 w - - 0 1"]

1. Bf4

[Result "69"]
[FEN "rk1b4/p2p2p1/1P6/2R2P2/8/2K5/8/5B2 w - - 0 1"]

1. Rc8 {win}

[Result "70"]
[FEN "3k4/4pp2/n2n4/5BN1/3N4/b7/4K3/8 w - - 0 1"]

1. Nxf7

[Result "71"]
[FEN "4b3/8/1P6/3K4/6p1/5pP1/5P1B/7k w - - 0 1"]

1. b7 Bb5 2. b8R

[Result "72"]
[FEN "8/5pKN/5Pp1/5kP1/8/Bb6/8/7q w - - 0 1"]

1. Bc5 {or any move} Qxh7+

[Result "73"]
[FEN "8/p5p1/1pP3p1/p5p1/k3p3/4p3/K7/8 w - - 0 1"]

1. c7 {win}

[Result "74"]
[FEN "q7/8/2p5/B2p2pp/5pp1/2N3k1/6P1/7K w - - 0 1"]

1. Ne4 Kh4 2. Ng3 fxg3 3. Bb6

[Result "75"]
[FEN "q7/7R/k7/1p6/1p6/1P2B3/7K/8 w - - 0 1"]

1. Bd4 {win}

[Result "76"]
[FEN "1q1r3k/3P1pp1/ppBR1n1p/4Q2P/P4P2/8/5PK1/8 w - - 0 1"]

1. Rxf6

[Result "77"]
[FEN "1r3q1k/2N2P1p/6pQ/4p3/7p/n6P/3B4/7K w - - 0 1"]

1. Qf4 {win}

[Result "78"]
[FEN "5nr1/2Pp2pk/3Pp1p1/4P1P1/6P1/5K2/8/7n w - - 0 1"]

1. c8N

[Result "79"]
[FEN "2K3k1/1p6/R3p1p1/1rB1P1P1/8/8/1Pb5/8 w - - 0 1"]

1. Rc6

[Result "80"]
[FEN "4q3/2r1r2p/3P3P/1p6/kP6/Pp6/1P6/KB2R3 w - - 0 1"]

1. Rxe7 Qxe7 {or 1... Rxe7 2. dxe7} 2. dxc7

[Result "81"]
[FEN "3k4/8/7p/2p1p1pP/1pPpPpP1/1P1P1P2/N7/2K5 w - - 0 1"]

{Na2->h4}

[Result "82"]
[FEN "8/8/8/1k3p2/p1p1pPp1/PpPpP1Pp/1P1P3P/QNK2NRR w - - 0 1"]

{win}

[Result "83"]
[FEN "4b1k1/P4pPp/1R3P1P/2r5/8/1P6/1K6/8 w - - 0 1"]

1. a8B

[Result "84"]
[FEN "4N2k/4PB1p/7P/B1p5/2P5/3q2Pp/1P3P1K/2r5 w - - 0 1"]

1. Bc3 Rxc3 2. Nc7

[Result "85"]
[FEN "1k6/3p4/1B6/4Pp1p/1p5R/1p4p1/pP3n2/K6n w - - 0 1"]

1. Rxh1 Nxh1 2. e6 dxe6 3. Bc7

[Result "86"]
[FEN "N3kb2/pq4p1/4B1P1/1p1P2B1/p7/3P4/2P5/2K5 w - - 0 1"]

1. Bf7 Kd7 2. Be6 Kd6 3. Bf4 Kc5 4. Be3 Kb4 5. Bd2 Ka3 6. Kb1

[Result "87"]
[FEN "8/1B3b1p/7P/p2p4/P2pp1kp/Q7/1N1Pq2P/7K w - - 0 1"]

1. Qh3

[Result "88"]
[FEN "1B2b2k/2N1qr2/4n2p/4p1PQ/1r2N3/1p6/7P/2KB4 w - - 0 1"]

1. Nd5 Rc4 2. Kb1 Rc1 3. Kb2 Rf2 4. Nf2 Rb1 5. Kb1 Qh7 6. g6 Bg6 7. Bc2 bxc2 8. Kc1 Bxh5 9. Be5 Ng7 10. Ne7

[Result "89"]
[FEN "2k4N/Q1np4/2p2Bpp/1p1P4/pPP1p2P/P7/7q/1K6 w - - 0 1"]

1. Nf7 Qg3 2. Qxc7 {win}

[Result "90"]
[FEN "8/4nk2/1p3p2/2rp2pp/1P1R1N1P/6P1/3KPP2/8 b - - 0 1"]

{avoid 1... Rb5}

[Result "91"]
[FEN "5BK1/5p1N/5Pp1/6Pk/8/1b6/8/7q b - - 0 1"]

1... Qa8 2.Kg7 Qd5 {or Qg2 and next Qxg5}

[Result "92"]
[FEN "2b5/1pr4p/3bp1pk/1p6/1PpN2PP/K1P1n3/P3N1R1/3R4 w - - 0 1"]

1. Nxb5 Nxd1 2. Nd6 b5 3. g5 Kh5 4. Nxc8 Rxc8 5. Nf4 Kxh4 6. Nxg6

[Result "93"]
[FEN "8/1p1pNpbk/q2P4/p3p2K/PP2N3/4P1P1/3P4/8 w - - 0 1"]

1. b5 Qb6 2. Nc8

[Result "94"]
[FEN "1rr5/6pk/7p/8/8/7P/1Pb1RRPK/8 b - - 0 1"]

{avoid Rxb2}

[Result "95"]
[FEN "6Q1/8/8/8/8/7k/ppp1p3/brrbK3 w - - 0 1"]

1. Qg1 {win}

[Result "96"]
[FEN "1B1K1k2/4N2p/3pP1pP/6p1/p7/3N2b1/2r2p2/8 w - - 0 1"]

1. Nc6 {win}

[Result "97"]
[FEN "8/4Pr1N/8/6PN/8/3K1ppp/4prkb/4Bbnn w - - 0 1"]

1. Nf8 {win}

[Result "98"]
[FEN "8/b7/3p2b1/5p1n/5Pk1/4P1p1/B5P1/R4K2 w - - 0 1"]

1. Ke2

[Result "99"]
[FEN "5K2/8/5B2/p7/8/p4p2/pn1PpPp1/kb2R3 w - - 0 1"]

1. Bh8 a4 2. Kg7 {win}

[Result "100"]
[FEN "3rqQ2/3ppppp/7k/R7/8/8/1PPP2K1/8 w - - 0 1"]

1. Ra3
[/pgn]

The authors of studies selected to the "IQ" test:

by YACPDB:

Mendheim Julius - 1
Blathy Otto - 3, 12, 13
Benko Pal - 16, 75
Hasek Josef - 22, 28
Gurvich Abram - 23
Kasparyan Genrikh - 24
Neghina Mihai - 27
Grasemann Herbert - 37
Popov Georgy & Hanyan Aleksei - 39 (part of study)
Rudolph William - 46
Troitzky Aleksei - 57
Reti Richard - 58
Matous Mario - 60
Behting Carl - 62
Klyatskin Mikhail - 66
Kubbel Karl - 69
Novomesky Daniel - 73
Lazard Frederic - 74
Marwitz Jan - 79
Lamford Paul - 82
Simkhovich Froim - 86

by other sources:

Solovyov Y. - 6
Babic M. - 10
Neghina Mihai - 11, 31, 35 (based on study), 84, 87, 89, 92
Simkhovich Froim - 20
van Breukelen Gijs - 36
Hoch Yehuda & Aloni Hillel - 55
Troitzky Aleksei - 59
Smyslov Vasily - 67
Bondarenko F. & Kuznetsov A. - 68
Surya Sekhar Ganguly - 81
Stavrietsky Aleksandr - 88
Kazantsev A. - 93
Ryabinin Nikolaj - 96
Neghina Mihai & Rusz Arpad- 97
Kamody Mario & Neghina Mihai - 98
Fekete Zoltan - 99 (part of study)

A pity, that Sting SF 21 loses its games on time !