Trivial or not?

[Gábor Szots]

Last game here under WB was this:

[Event "Thinker 1"]
[Site "LUCIFER"]
[Date "2009.08.15"]
[Round "-"]
[White "Arasan 11.2 (2 cpus)"]
[Black "Petir 4.999999"]
[Result "1-0"]
[TimeControl "40/1560"]
[Annotator "11. +0.60 11... -0.58"]

1. Nf3 Nf6 2. d4 d5 3. c4 dxc4 4. e3 e6 5. Bxc4 c5 6. Nc3 a6 7. O-O Nc6 8.
dxc5 Bxc5 9. Qxd8+ Kxd8 10. a3 Ke7 11. b4 {+0.60/15 51} Bd6 {-0.58/17 1:50}
12. Bb2 {+0.60/15 51} b5 {-0.60/16 50} 13. Bd3 {+0.50/15 51} Bb7
{-0.54/16 50} 14. Ne4 {+0.52/15 51} Ne5 {-0.51/16 50} 15. Nxd6
{+0.32/17 51} Nxf3+ {-0.66/17 50} 16. gxf3 {+0.46/16 51} Kxd6 {-0.64/17 50}
17. f4 {+0.45/15 51} Ke7 {-0.65/16 49} 18. a4 {+0.54/15 51} Rhd8
{-0.57/16 49} 19. Bd4 {+0.42/16 51} Nd5 {-0.54/16 54} 20. Rfc1
{+0.39/15 51} bxa4 21. Rxa4 {+0.20/14 51} Nxf4 {-0.29/16 49} 22. Rc7+
{+0.16/15 51} Ke8 {-0.53/16 49} 23. Bf1 {+0.12/17 52} Bf3 {-0.21/15 49} 24.
Bxg7 {+0.12/16 52} Ne2+ {-0.25/16 49} 25. Bxe2 {+0.12/2 0.1} Bxe2
{-0.29/17 49} 26. Bf6 {+0.08/16 55} Rdc8 {-0.28/17 49} 27. Re7+
{+0.08/17 55} Kf8 28. h3 {+0.08/16 55} Rc1+ {-0.27/17 48} 29. Kg2
{+0.24/14 55} Bc4 {-0.24/16 48} 30. e4 {+0.28/14 55} Re8 {-0.23/16 53} 31.
Ra7 {+0.36/15 55} Bd3 {-0.25/15 48} 32. Kg3 {+0.39/14 55} Rb1 {-0.23/15 43}
33. Ra3 {+0.44/15 55} Bxe4 {-0.30/16 1:04} 34. Bd4 {+0.41/14 55} e5
{-0.28/15 50} 35. Bc5+ {+0.44/16 55} Kg7 36. R7xa6 {+0.44/16 55} Kh8
{-0.27/14 44} 37. Re3 {+0.60/14 56} f5 {-0.45/15 48} 38. Kh4 {+0.64/15 56}
Rc1 {-0.53/15 42} 39. Rg3 {+0.88/15 56} Rc4 {-0.55/16 46} 40. Ra7
{+0.92/15 57} Re6 {-0.64/16 39} 41. Kh5 {+0.95/16 39} f4 {-0.65/16 40} 42.
Rga3 {+1.15/14 39} f3 {-0.76/16 1:03} 43. R3a6 {+1.12/16 39} Rxa6
{-0.80/16 40} 44. Rxa6 {+1.52/16 39} Bd3 {-0.87/17 40} 45. Kg5
{+1.59/16 39} Rg4+ {-0.84/19 1:04} 46. hxg4 {+1.78/21 39} Bxa6
{-1.08/24 42} 47. Kf5 {+1.81/22 39} Kg7 {-1.13/25 39} 48. g5 {+2.03/24 39}
Bd3+ {-1.06/27 1:14} 49. Kxe5 {+2.15/27 39} Kg6 {-1.06/26 37} 50. Be3
{+2.15/26 39} Kf7 {-1.06/26 37} 51. Kd6 {+2.15/26 39} Ke8 {-1.06/28 41} 52.
Kc6 {+2.15/27 39} Be4+ {-1.06/31 41} 53. Kc7 {+2.15/27 39} Bd3
{-1.08/27 41} 54. Bd4 {+2.15/25 39} Kf7 {-1.06/27 37} 55. Kd6 {+2.14/24 39}
Ke8 {-1.06/29 48} 56. Bf6 {+2.14/23 39} Kf7 {-1.06/27 44} 57. Bd8
{+2.14/24 39} Ke8 {-1.06/27 43} 58. Bb6 {+2.14/27 39} Kf7 {-1.06/26 39} 59.
Bd4 {+2.14/26 39} Ke8 {-1.06/29 46} 60. Kc6 {+2.14/26 39} Be4+
{-1.07/29 38} 61. Kc7 {+2.14/28 39} Bd3 {-1.06/28 38} 62. Bc5 {+2.14/27 39}
Kf7 {-1.06/27 38} 63. Kc6 {+2.12/26 39} Be4+ {-1.07/28 34} 64. Kd7
{+2.12/26 39} Bf5+ {-1.06/27 38} 65. Kd6 {+2.12/27 39} Bd3 {-1.07/27 34}
66. Ba7 {+2.12/26 39} Ke8 {-1.06/27 37} 67. Bd4 {+2.12/25 39} Kf7
{-1.06/27 33} 68. Kd7 {+2.11/25 39} Bb5+ {-0.56/28 40} 69. Kc8
{+1.71/25 1:18} Ke6 {-0.55/27 48} 70. Kc7 {+1.71/26 36} Kd5 {-0.56/28 34}
71. Ba7 {+1.71/25 36} Kc4 {-0.56/30 34} 72. Bc5 {+1.71/26 36} Kd5
{-0.56/30 31} 73. Bd6 {+1.71/26 36} Ba4 {-0.56/30 30} 74. Bf8 {+1.71/27 36}
Bc6 {-0.56/29 42} 75. Bg7 {+1.71/26 36} Bb5 {-0.57/27 40} 76. Kb6
{+1.71/26 36} Be8 {-0.57/27 26} 77. Bf8 {+1.71/26 36} Bd7 {-0.56/28 26} 78.
Kb7 {+1.71/24 36} Bb5 {-0.56/26 37} 79. Bc5 {+1.71/26 36} Bc6+
{-0.57/27 26} 80. Ka6 {+1.71/26 36} Bd7 {-0.56/26 21} 81. Kb6 {+1.71/26 39}
Ba4 {-0.56/28 1:11} 82. Bf8 {+1.71/25 39} Be8 {-0.53/27 54} 83. Be7
{+1.71/26 39} Ke6 {-0.54/29 50} 84. Bd8 {+1.71/24 39} Kd5 {-0.46/28 42} 85.
Ka6 {+1.71/26 39} Kc4 {-0.40/25 42} 86. Be7 {+1.71/27 39} Bb5+
{-0.38/28 38} 87. Kb6 {+1.71/26 39} Be8 {-0.38/27 38} 88. Bd6 {+1.71/26 39}
Kd5 {-0.32/28 41} 89. Bf8 {+1.71/24 39} Kc4 {-0.32/27 49} 90. Bd6
{+1.71/25 39} Kd5 {-0.32/27 48} 91. Bh2 {+1.71/26 39} Kc4 {-0.22/29 40} 92.
Ka5 {+1.71/28 39} Bd7 {-0.22/27 40} 93. Be5 {+0.68/28 1:18} Be8
{-0.14/27 36} 94. Bg7 {+0.68/26 37} Bb5 {-0.08/24 2.9} 95. Bf8
{+0.68/27 37} Be8 {-0.08/27 24} 96. Bg7 {+0.68/27 37} Bb5 {-0.08/26 38} 97.
Bh8 {+0.68/26 37} Be8 {-0.06/26 2.8} 98. Bf6 {+0.68/26 37} Bd7
{-0.06/30 25} 99. g6 {+0.68/27 37} hxg6 {-0.05/29 40} 100. Be5
{+0.68/26 37} g5 {+0.00/24 2.8} 101. Bf6 {+0.68/25 37} g4 {+0.00/24 3} 102.
Be5 {+0.68/25 37} Kd5 {+0.00/29 28} 103. Bb8 {+0.68/24 38} Kc4 {+0.00/27 3}
104. Bh2 {+0.67/23 38} Be8 {+0.00/27 3} 105. Bf4 {+0.64/23 38} Bb5
{+0.00/27 4} 106. Bc7 {+0.63/25 38} Bc6 {+0.00/26 3} 107. Bg3 {+0.63/24 38}
Be8 {+0.00/27 4} 108. Be5 {+0.56/23 38} Kd5 {+0.00/28 30} 109. Bg3
{+0.56/25 38} Kc4 {+0.00/28 4} 110. Bf4 {+0.56/22 38} Bb5 {+0.00/32 53}
111. Be5 {+0.56/25 38} Be8 {+0.00/27 5} 112. Bc7 {+0.56/24 38} Bd7
{+0.00/28 6} 113. Be5 {+0.40/25 38} Kd5 {+0.00/29 6} 114. Bf4 {+0.39/24 38}
Kc4 {+0.00/28 6} 115. Bb8 {+0.01/23 38} Bb5 {+0.00/31 8} 116. Ba7
{+0.01/23 38} Bd7 {+0.00/24 9} 117. Bc5 {+0.00/22 38} Bf5 {+0.00/28 1:29}
118. Kb6 {+0.40/22 38} Be4 {+0.00/29 2:30} 119. Kc7 {+0.40/22 38} Bd3
{+0.00/25 10} 120. Kc6 {+0.40/23 38} Bc2 {+0.00/28 19} 121. Kd6
{+0.40/24 39} g3 {+0.00/26 4} 122. fxg3 {+1.02/23 39} Bf5 {+0.00/28 40}
123. Ke5 {+1.01/24 39} Bd7 {+0.00/27 51} 124. Ke4 {+1.01/22 39} f2
{+0.00/27 3} 125. Bxf2 {+1.01/28 39} Kxb4 {+0.00/33 20} 126. Bd4
{+1.01/33 39} Kc4 {+0.00/28 3} 127. Bf6 {+1.01/34 39} Kb3 {+0.00/32 4} 128.
Kd3 {+1.01/35 39} Bf5+ {+0.00/33 4} 129. Kd2 {+0.95/37 39} Bd7
{+0.00/38 22} 130. Ke3 {+0.95/36 39} Bf5 {+0.00/34 4} 131. Bd8
{+0.95/36 39} Kc4 {+0.00/32 4} 132. Kf4 {+0.95/35 39} Bc2 {+0.00/31 4} 133.
g4 {+1.15/31 39} Kd5 {+0.00/31 4} 134. Bc7 {+1.15/32 39} Bd1 {+0.00/29 5}
135. g5 {+1.15/34 39} Bc2 {+0.00/35 24} 136. Bd8 {+1.15/35 39} Ke6
{+0.00/33 5} 137. Ba5 {+1.15/35 39} Kf7 {+0.00/36 5} 138. Ke5 {+1.27/36 39}
Bd3 {+0.00/35 5} 139. Bc3 {+1.27/36 39} Bc2 {+0.00/36 6} 140. Bd4
{+1.27/37 39} Kg6 {+0.00/38 5} 141. Be3 {+1.27/38 39} Bf5 {+0.00/36 6} 142.
Bf4 {+1.27/38 39} Bd3 {+0.00/37 1:25} 143. Ke6 {+1.27/37 39} Bc4+
{+0.00/34 6} 144. Ke7 {+1.27/38 39} Kf5 {+0.00/36 1:16} 145. Bd2
{+1.27/37 39} Bb3 {+0.00/35 7} 146. Kf8 {+1.27/37 39} Kg6 {+0.00/36 7} 147.
Bf4 {+1.27/39 39} Kf5 {+0.00/35 7} 148. Be3 {+1.27/36 39} Kg6 {+0.00/41 8}
149. Bf4 {+1.27/39 39} Kf5 {+0.00/41 1:00} 150. Be3 {+1.27/38 39} Kg6 151.
Bd2 {+1.27/39 39} Bc2 {+0.00/34 9} 152. Bf4 {+1.27/40 39} Kf5
{+0.00/35 2:11} 153. Be3 {+1.27/35 39} Kg6 {+0.00/39 10} 154. Kg8
{+1.04/36 39} Bb3+ {+0.00/49 11} 155. Kf8 {+1.15/36 39} Kh7 {+0.00/42 12}
156. Ke8 {+1.15/37 39} Kg6 {+0.00/42 14} 157. Ke7 {+1.15/37 39} Kf5
{+0.00/36 17} 158. Bc1 {+1.15/37 40} Kg6 {+0.00/50 4} 159. Kd6
{+1.15/38 40} Kf5 {+0.00/42 28} 160. Ke7 {+1.15/37 40} Kg6 {+0.00/50 0.1}
161. Bd2 {+1.15/36 39} Bc4 {+0.00/46 6} 162. Bf4 {+1.15/37 39} Kf5
{+0.00/39 1:05} 163. Bd2 {+1.15/35 39} Bb3 {+0.00/39 5} 164. Ke8
{+1.09/36 39} Kg6 {+0.00/40 5} 165. Bf4 {+1.09/36 39} Kf5 {+0.00/35 5} 166.
Be3 {+1.09/35 39} Be6 {+0.00/34 5} 167. Kf8 {+1.09/36 39} Kg6 {+0.00/35 5}
168. Ke7 {+1.09/37 39} Kf5 {+0.00/38 6} 169. Kf8 {+1.09/37 39} Kg6
{+0.00/41 33} 170. Bc1 {+0.03/37 1:17} Bb3 {+0.00/50 0.9} 171. Ke8
{+0.00/38 37} Kf5 {+0.00/43 55} 172. Kd7 {+0.00/35 38} Kg6 {+0.00/43 6}
173. Kd6 {+0.00/39 37} Kf5 {+0.00/44 1:28} 174. Be3 {+0.00/39 37} Kg6
{+0.00/39 6} 175. Ke7 {+0.00/40 37} Kf5 {+0.00/34 6} 176. Kd6 {+0.00/40 38}
Kg6 {+0.00/43 1:16} 177. Ke5 {+0.00/41 38} Bc2 {+0.00/39 7} 178. Bd2
{+0.00/43 37} Kf7 {+0.00/42 7} 179. Bb4 {+0.00/41 38} Kg6 {+0.00/37 7} 180.
Be7 {+0.00/44 38} Bb3 {+0.00/37 7} 181. Bd8 {+0.00/46 38} Kf7 {+0.00/37 8}
182. Kf5 {+0.00/44 38} Be6+ {+0.00/38 8} 183. Ke5 {+0.00/45 38} Bb3
{+0.00/39 9} 184. Bb6 {+0.00/45 38} Bc2 {+0.00/48 9} 185. g6+ {+0.00/53 38}
Kxg6 {+0.00/36 10} 186. Bc5 {+0.00/3 0.1}
{False draw claim: ''} 1-0

Although there is mating material on the board, so maybe Petir's claim was incorrect, trivial draws were checked so should WB not adjudicate a draw without waiting for Arasan to move?

[H.G.Muller]

I am afraid it is not trivial enough...

Only KNKN, KNNK, KBKN, KBKB (unlike), KRKR and KQKQ are recognized as trivial draws. I agree this would be a good candidate to add, but the line will have to be drawn somewhere, and there will always be boundary cases.

[Gábor Szots]

I am afraid it is not trivial enough...

Only KNKN, KNNK, KBKN, KBKB (unlike), KRKR and KQKQ are recognized as trivial draws. I agree this would be a good candidate to add, but the line will have to be drawn somewhere, and there will always be boundary cases.

Hi HG,

I think KBKB with same coloured bishops is not a trivial draw but insufficient material. KBKB with different coloured bishops should be recognized as a trivial draw (unless the side to move can mate in 1).

And, KBBK (bishops of same colour!) is insufficient material as well.

In fact I think KNNK and KBKB (diffferent) should be treated alike. They both can only mate if the opponent wants it.

And, KQKQ and KRKR should be trivial draws only if the side to move cannot win the other side's piece immediately...

[Teemu Pudas]

And, KQKQ and KRKR should be trivial draws only if the side to move cannot win the other side's piece immediately...

"Immediately" can be about 10 moves long in KQKQ...

[H.G.Muller]

KBKB with different coloured bishops should be recognized as a trivial draw (unless the side to move can mate in 1).

That is what I mean by "(unlike)": on different colors.

KBBK (like) is also insufficiet material, and will be recognized as such. In fact WB now recognizes andy number of Bisops against any other number of Bishops as insuff. material draw, if all Bishops are on the same color.

But the problem in the game you show is that there still is a Pawn.

As to KRKR: the way it works is that WB declares the trivial draw only after 3 moves. So if one side can forcibly win the Rook in the position you first have KRKR, it gets the time to do so. For KQKQ this is not strctly correct. But for KBPKB (unlike) it might work, as think the only positions where you cannot trivially stop promotion (by covering a square in front of the Pawn with your Bishop) have promotion within 3 moves.

[H.G.Muller]

"Immediately" can be about 10 moves long in KQKQ...

Yes, I know. This was just a temporry measure, when I hav implemented bitbase-based adjudication I will probably take it out again.

[Gábor Szots]

But the problem in the game you show is that there still is a Pawn.

Where? It has just been captured (Kxg6). The final position is KBKB.

[H.G.Muller]

Ah, sorry. Seems I lost a few moves...

OK, so this would be a trivial draw, but WB only rules trivial draws after 3 moves. It must build in a certain delay, because the side to move might be able to checkmate in one, and then you don't want to declare it draw. The only reason to have trivial draw adjudication is to save some time, not to show off how smart the GUI is, so I didn't see much need for making the number of moves to wait dependent on the material. I just picked 3, because that is what you might need to win KRKR when it is winnable. That sometimes it could be two shorter is not very significant, but you don't want to wait out 50 moves.

So if the engines had played on it would have been adjudicated draw quite quickly.