Test positions for beginners or bad chess players

[hgm]

Skipper also having trouble with this position. Although it finds a check mate in the end. Enough to do.

[d] 3qk3/8/8/4K3/8/8/8/8 w - - 0 1

The first Chess program I wrote did only search 2 ply + recaptures, and it would not have had any problem at all with the above position.

The problems started once I had improved it so much that it could also see mate in 2 (i.e. 3 ply search + check extension + recaptures). Then it would prefer mate in 2 over mate in one, because it gave a penalty for moving the King, and wanted to cash that penalty from the opponent by forcing it to do an extra King move!

[Joost Buijs]

The first Chess program I wrote did only search 2 ply + recaptures, and it would not have had any problem at all with the above position.

Those were the days!

My first chess program searched 3 ply and was able to win KQK and KRK by just driving the king to a corner and then it was able to find the mate, this was in 1978.
Although my move generator (in assembler) did 15 Kn/sec. the whole program searched a mere 700 n/sec. (2MHz. 8080).

Times have changed though!

[jdart]

This should be easy. Just give a bonus for K+Q vs K that rewards the side with the Queen for driving the weaker side to the edge of the board. Then if you have any kind of reasonably good search, it should find the mate.

--Jon

[Henk]

This position is a level more difficult [at least for Skipper for it had much problems finishing this end game]

[d] 7k/6p1/8/8/6q1/4K3/8/8 b - - 1 54

[Daniel Anulliero]

This position is a level more difficult [at least for Skipper for it had much problems finishing this end game]

[d] 7k/6p1/8/8/6q1/4K3/8/8 b - - 1 54

Really skipper have problems to win this ?
You have DEFINITELY SOMETHING VERY WRONG in your program!
See the two posts above by Misters Muller and Buijs : their programs solve these kind of positions in 1978 years , 30 years ago ! Lol
Please listen dôme prgrammer's advices !

[Henk]

Yes see move 71 .. 140 etc.

[pgn]
[Event "Computer Chess Game"]
[Site "HP"]
[Date "2016.04.24"]
[Round "-"]
[White "Fairy-Max 4.8S"]
[Black "SkipperWinb"]
[Result "0-1"]
[TimeControl "120"]
[Annotator "1. +0.12 1... +0.06"]

1. c4 {+0.12/8} e5 {+0.06/14 2.5} 2. d4 {+0.17/8 4} exd4 {+0.03/12 2.4} 3.
Qxd4 {-0.25/9 7} Nc6 {+0.05/12 2.4} 4. Qe4+ {-0.10/8 2.6} Qe7
{+0.17/14 2.3} 5. Qxe7+ {-0.07/8 2.4} Bxe7 {+0.05/13 2.3} 6. Nc3
{+0.07/8 2.3} Nd4 {-0.02/12 2.2} 7. Nd5 {-0.10/9 2.3} Bd6 {+0.00/13 2.2} 8.
Rb1 {-0.13/9 4} Nf6 {-0.09/13 2.1} 9. Nxf6+ {-0.01/9 1.5} gxf6
{-0.25/14 2.2} 10. Bd2 {-0.02/10 5} O-O {-0.17/13 2.0} 11. Bc3 {+0.11/9 3}
Bb4 {-0.19/15 2.0} 12. e3 {+0.04/9 1.7} Nc6 {-0.14/13 2.0} 13. Nf3
{+0.06/9 2.2} Bxc3+ {-0.15/16 2.0} 14. bxc3 {-0.03/10 1.1} b6
{-0.16/14 2.0} 15. Bd3 {+0.16/10 2.9} Ba6 {-0.11/13 1.9} 16. e4
{+0.07/9 1.2} d6 {-0.11/11 1.8} 17. Nd2 {+0.02/10 3} Ne5 {-0.08/13 1.8} 18.
Be2 {+0.14/10 1.7} Ng6 {+0.10/13 1.8} 19. O-O {+0.16/9 1.1} Nf4
{-0.05/13 1.7} 20. Bf3 {-0.12/10 2.1} Rae8 {+0.05/15 1.7} 21. h4
{-0.08/9 1.2} Bb7 {+0.08/13 2.1} 22. Rfd1 {-0.21/8 1.4} Nd3 {+0.21/12 2.0}
23. Bg4 {-0.25/8 0.9} Ne5 {+0.17/13 2.0} 24. Bf5 {-0.18/9 0.9} a5
{+0.28/14 2.0} 25. f4 {-0.18/9 0.9} Nd3 {+0.23/15 1.9} 26. Rf1
{-0.12/10 1.8} Nc5 {+0.06/13 1.9} 27. Rbe1 {-0.12/10 1.5} Re7
{+0.03/14 1.8} 28. Rf3 {-0.06/9 0.8} Rfe8 {+0.02/14 1.8} 29. Rg3+
{+0.10/9 1.0} Kh8 {+0.08/16 1.8} 30. h5 {-0.43/9 1.4} Ne6 {+0.36/14 1.7}
31. h6 {-0.17/9 0.9} Nxf4 {+0.74/14 1.8} 32. Rg7 {-0.10/9 1.4} Ng6
{+0.74/11 1.6} 33. Rf1 {-0.16/9 1.3} Rf8 {+0.68/14 1.6} 34. a4
{-0.17/9 1.1} Bc6 {+0.72/14 1.6} 35. Ra1 {-0.10/10 2.0} Rfe8 {+0.74/13 1.5}
36. Ra2 {-0.17/9 1.0} Bd7 {+0.80/13 1.5} 37. g4 {-0.22/9 1.0} Bxf5
{+0.92/13 1.5} 38. gxf5 {-0.32/10 1.1} Ne5 {+0.96/15 1.7} 39. Ra1
{-0.27/10 0.9} Nd3 {+1.12/13 1.3} 40. Ra3 {-0.69/11 1.0} Nc5 {+0.96/15 1.2}
41. Kg2 {-0.94/11 1.3} Nxe4 {+1.01/15 0.8} 42. Nxe4 {-0.92/10 0.8} Rxe4
{+1.01/15 0.9} 43. Rxf7 {-0.85/11 1.3} Rxc4 {+0.82/11 0.8} 44. Rxf6
{-0.82/10 0.8} Kg8 {+1.35/13 0.8} 45. Re6 {-1.10/10 0.6} Rf8 {+1.61/16 0.7}
46. Re7 {-1.13/10 0.7} Rxf5 {+1.78/13 0.7} 47. Rg7+ {-1.39/10 0.6} Kh8
{+1.85/16 0.7} 48. Rd7 {-1.73/11 0.9} Rg4+ {+1.86/14 0.7} 49. Kh3
{-2.79/13 0.6} Rg8 {+2.61/16 0.7} 50. Rg7 {-2.76/14 1.0} Rf6 {+2.51/16 0.7}
51. Rxg8+ {-2.54/12 1.0} Kxg8 {+2.37/17 0.7} 52. c4 {-2.29/13 1.0} Rxh6+
{+2.64/15 0.7} 53. Kg3 {-2.30/13 1.4} Rh5 {+2.66/15 0.6} 54. Re3
{-2.35/12 0.6} Re5 {+2.62/15 0.6} 55. Rxe5 {-1.87/18 0.5} dxe5
{+2.29/21 0.7} 56. Kg4 {-2.27/17 2.2} e4 {+1.94/18 0.6} 57. Kf4
{-2.27/16 0.7} Kf7 {+2.02/21 0.6} 58. Ke3 {-2.31/14 0.4} Ke6 {+2.38/20 0.6}
59. Kxe4 {-2.31/15 0.4} h5 {+2.72/21 0.6} 60. Kf4 {-2.32/16 1.0} Kd6
{+2.96/23 0.6} 61. Ke3 {-3.57/16 1.7} Kc5 {+3.87/22 0.6} 62. Kd3
{-8.99/16 0.5} h4 {+4.64/22 0.6} 63. Ke3 {-9.86/16 0.5} Kxc4 {+5.08/22 0.5}
64. Ke4 {-9.94/16 0.5} c5 {+6.11/21 0.5} 65. Ke3 {-9.97/16 0.3} Kb3
{+8.34/18 0.5} 66. Kf3 {-10.68/16 0.5} c4 {+10.30/22 0.5} 67. Kg4
{-11.18/16 0.5} c3 {+10.30/21 0.5} 68. Kxh4 {-11.09/15 0.4} c2
{+10.30/20 0.5} 69. Kg4 {-17.47/14 0.5} c1=Q {+10.30/14 0.5} 70. Kh5
{-17.48/12 0.4} Kxa4 {+10.30/14 0.5} 71. Kg4 {-17.75/12 0.4} Qc8+
{+10.30/13 0.5} 72. Kf3 {-17.80/13 0.8} Qc6+ {+10.30/14 0.5} 73. Kf4
{-17.82/12 0.3} Qc4+ {+10.30/15 0.5} 74. Ke5 {-17.84/12 0.3} Qc7+
{+10.30/13 0.5} 75. Kd5 {-17.85/12 0.3} Qc5+ {+10.30/12 0.5} 76. Ke4
{-17.85/13 0.3} Qg1 {+10.30/17 0.4} 77. Kd5 {-17.84/12 0.3} Qg2+
{+10.30/10 0.4} 78. Ke6 {-17.84/12 0.3} Qg4+ {+10.30/10 0.4} 79. Kd6
{-17.84/12 0.3} Qc8 {+10.30/14 0.4} 80. Ke5 {-17.83/13 0.3} Qh3
{+10.30/15 0.4} 81. Kd6 {-17.84/12 0.3} Qe3 {+8.60/7 0.4} 82. Kd5
{-17.85/12 0.3} Qf3+ {+10.30/10 0.4} 83. Ke6 {-17.85/13 0.4} Qc6+
{+10.30/13 0.4} 84. Kf5 {-17.83/13 0.3} Qe8 {+10.30/11 0.4} 85. Kf6
{-17.84/13 0.4} Qf8+ {+10.30/12 0.4} 86. Ke5 {-17.80/13 0.3} Qg7+
{+10.30/11 0.4} 87. Kf5 {-17.84/12 0.2} Qf7+ {+10.30/16 0.4} 88. Ke4
{-17.84/13 0.3} Qb3 {+10.30/17 0.4} 89. Kf4 {-17.84/13 0.2} Qb4+
{+10.30/13 0.3} 90. Kf5 {-17.83/12 0.2} Qb1+ {+10.30/12 0.3} 91. Ke5
{-17.83/12 0.3} Qb5+ {+10.30/10 0.3} 92. Kd6 {-17.86/13 0.2} Qc5+
{+8.60/7 0.3} 93. Ke6 {-17.87/13 0.2} Qd4 {+10.30/13 0.3} 94. Ke7
{-17.86/13 0.2} Qd5 {+10.30/13 0.3} 95. Kf6 {-17.92/14 0.4} Qd6+
{+10.30/13 0.3} 96. Kf5 {-17.85/13 0.2} Qd2 {+10.30/17 0.3} 97. Ke6
{-17.83/12 0.2} Qd8 {+10.30/16 0.3} 98. Ke5 {-17.86/14 0.3} b5
{+8.48/8 0.3} 99. Kf4 {-17.85/13 0.3} Qf6+ {+8.54/6 0.3} 100. Ke4
{-17.83/12 0.2} Qc6+ {+8.53/6 0.3} 101. Kd4 {-17.85/12 0.2} Qd6+
{+8.54/7 0.3} 102. Ke4 {-18.47/14 0.5} Qc5 {+8.54/7 0.3} 103. Kf4
{-18.47/14 0.2} Qd4+ {+8.54/6 0.3} 104. Kf3 {-17.97/13 0.4} Qd5+
{+8.53/6 0.3} 105. Kf4 {-17.97/13 0.1} Qd2+ {+8.53/7 0.3} 106. Ke5
{-18.46/13 0.2} Qc3+ {+8.49/8 0.3} 107. Kd6 {-17.81/11 0.1} Qf6+
{+8.50/9 0.3} 108. Kd7 {-17.91/12 0.2} Qf7+ {+8.49/8 0.3} 109. Kd6
{-17.87/12 0.2} Qf4+ {+8.49/9 0.2} 110. Ke6 {-17.87/12 0.2} Qc7
{+8.51/10 0.3} 111. Kd5 {-17.88/13 0.3} Qd7+ {+8.54/10 0.2} 112. Ke5
{-17.90/13 0.1} Kb3 {+8.51/9 0.2} 113. Kf6 {-17.89/12 0.2} Qd4+
{+8.46/7 0.2} 114. Ke7 {-17.89/11 0.1} Ka4 {+8.49/8 0.2} 115. Kf7
{-17.90/13 0.2} Qf2+ {+8.49/8 0.2} 116. Ke6 {-17.88/13 0.2} Qb6+
{+8.50/9 0.3} 117. Ke7 {-17.90/13 0.2} Qb7+ {+8.49/10 0.2} 118. Ke6
{-17.89/13 0.1} Qa6+ {+8.50/8 0.2} 119. Ke5 {-79.79/14 0.3} Qb6
{+8.51/12 0.2} 120. Kf5 {-79.80/14 0.2} Qc6 {+8.51/10 0.2} 121. Ke5
{-79.80/14 0.2} Qh6 {+8.51/10 0.2} 122. Kf5 {-79.80/14 0.3} Qg7
{+8.49/8 0.2} 123. Ke6 {-17.89/12 0.1} Qg6+ {+8.49/8 0.2} 124. Kd7
{-17.91/13 0.1} Qh6 {+8.49/8 0.2} 125. Ke7 {-17.92/13 0.1} Qh7+
{+8.49/9 0.2} 126. Ke6 {-17.88/12 0.1} Qh3+ {+8.50/9 0.2} 127. Kd6
{-17.89/13 0.2} Qg4 {+8.50/10 0.2} 128. Ke7 {-17.90/13 0.1} Qh4+
{+8.49/8 0.2} 129. Kd6 {-17.89/13 0.1} Qg3+ {+8.50/9 0.2} 130. Ke6
{-17.90/13 0.2} Qd3 {+8.49/9 0.2} 131. Ke7 {-18.45/14 0.3} Qd2
{+8.49/9 0.2} 132. Ke6 {-18.44/13 0.1} Qe1+ {+8.50/10 0.2} 133. Kd6
{-17.90/13 0.1} Qe8 {+8.54/11 0.2} 134. Kc7 {-79.74/13 0.2} Qe7+
{+8.51/10 0.2} 135. Kc6 {-79.81/13 0.2} Qd8 {+8.58/11 0.2} 136. Kb7
{-79.95/14 0.1} Qd7+ {+8.62/12 0.2} 137. Ka8 {-79.96/12 0.1} Qc8+
{+8.58/11 0.2} 138. Ka7 {-79.96/16 0.2} Qc7+ {+8.62/12 0.1} 139. Ka8
{-79.95/13 0.1} Qd7 {+8.62/15 0.2} 140. Kb8 {-79.96/17 0.2} Kb3
{+8.55/11 0.1} 141. Ka8 {-79.96/11 0.1} Qc8+ {+8.58/10 0.2} 142. Ka7
{-79.96/13 0.1} Kb4 {+8.56/11 0.1} 143. Kb6 {-79.97/27 0.2} Qd7
{+8.63/10 0.1} 144. Ka6 {-79.98/28 0.2} Kc5 {+3355.44/8 0.1} 145. Kxa5
{-79.99/28 0.2} Qa7# {+3355.44/1 0.1}
{Xboard adjudication: Checkmate} 0-1
[/pgn]

[Henk]

Increased passed pawn bonus when opponent has bare king
[pgn]
[Event "Computer Chess Game"]
[Site "HP"]
[Date "2016.04.25"]
[Round "-"]
[White "Stockfish 6 64"]
[Black "SkipperWinb"]
[Result "0-1"]
[TimeControl "10"]
[FEN "8/8/1p6/p3K3/k1q5/8/8/8 b - - 7 1"]
[SetUp "1"]

{--------------
. . . . . . . .
. . . . . . . .
. p . . . . . .
p . . . K . . .
k . q . . . . .
. . . . . . . .
. . . . . . . .
. . . . . . . .
black to play
--------------}
1... b5 {+16.48/2 0.1} 2. Kf5 {-99.86/23 0.2} Qf7+ {+21.61/5 0.1} 3. Ke4
{-99.86/22 0.2} Qe6+ {+39.52/6 0.1} 4. Kf4 {-99.86/24 0.2} b4
{+39.50/7 0.1} 5. Kg5 {-99.88/26 0.2} Qe5+ {+26.73/5 0.1} 6. Kg4
{-99.90/32 0.2} b3 {+49.76/7 0.1} 7. Kf3 {-99.92/67 0.2} b2 {+50.36/5 0.1}
8. Kg4 {-99.94/102 0.2} b1=Q {+3355.44/4 0.1} 9. Kf3 {-99.96/103 0.2} Qh1+
{+3355.44/2 0.1} 10. Kg4 {-99.98/127 0.3} Qhh5# {+3355.44/1 0.1}
{Xboard adjudication: Checkmate} 0-1
[/pgn]

Not optimal though.

[pgn]
[Event "Computer Chess Game"]
[Site "HP"]
[Date "2016.04.25"]
[Round "-"]
[White "Stockfish 6 64"]
[Black "Stockfish 6 64"]
[Result "0-1"]
[TimeControl "10"]
[FEN "8/8/1p6/p3K3/k1q5/8/8/8 b - - 7 1"]
[SetUp "1"]

{--------------
. . . . . . . .
. . . . . . . .
. p . . . . . .
p . . . K . . .
k . q . . . . .
. . . . . . . .
. . . . . . . .
. . . . . . . .
black to play
--------------}
1... Kb3 {+99.83/17 0.1} 2. Kf5 {-99.86/21 0.2} a4 {+99.87/21 0.2} 3. Kg6
{-99.88/24 0.2} a3 {+99.89/23 0.2} 4. Kf5 {-99.90/29 0.2} a2
{+99.91/27 0.1} 5. Kg6 {-99.92/39 0.2} Qd5 {+99.93/41 0.2} 6. Kh7
{-99.94/92 0.2} a1=Q {+99.95/97 0.2} 7. Kg6 {-99.96/127 0.3} Qg1+
{+99.97/127 0.2} 8. Kh7 {-99.98/127 0.3} Qdh1# {+99.99/121 0.2}
{Xboard adjudication: Checkmate} 0-1
[/pgn]