# Question
Title: What is the longest known stalemate your opponent in x-moves problem?
What is the longest known stalemate your opponent in x-moves problem where the given stalemate is the fastest one from the initial position? A win is not possible, but stalemating your opponent so they can't move is, and any other draw takes at least as many moves.

The solution does not have to be unique. The stalemating side will try to keep the game as short as possible, while the to-be-stalemated attempts to prolong it.

Here is an example of such a "stalemate your opponent" problem that is in 2 moves long.

```
[FEN "5k1K/8/7P/8/8/7b/8/8 b - - 0 1"]
[startflipped ""]

1... Bf5 2. h7 Kf7.

```

Another example is this with White to move. It is the record for White having only a king.

```
[Title "CJ Morse, The Problemist 1985"]
[FEN "8/ppp1p3/4p3/4p3/8/8/1pp5/brk1K3 w - - 0 1"]

1. Ke2 e4 2. Ke1 e3 3. Ke2 e5 4. Ke1 e2 5. Kxe2 e4 6. Ke1 e3 7. Ke2 e6 8. Ke1 e2 9. Kxe2 e5 10. Ke1 e4 11. Ke2 e3 12. Ke1 e2 13. Kxe2 c6 14. Ke1 c5 15. Ke2 c4 16. Ke1 c3 17. Ke2 b6 18. Ke1 b5 19. Ke2 b4 20. Ke1 b3 21. Ke2 a6 22. Ke1 a5 23. Ke2 a4 24. Ke1 a3 25. Ke2 a2 26. Ke1

```

Can anyone find a longer fastest stalemate your opponent in x-moves problem than the 35-move one below that I created?

# Answer
> 7 votes
The following thirty five move position is the longest position I could create.

White basically checks with four knights on c2 before blocking the black pawns with the king and knight on h1 while keeping the black king boxed in on a1. I tried extending this by adding another white knight on a3 to check on c2 but a black queen or black bishop cannot be added to capture on c2 since black still has eight pawns and there would be no square to place a black knight on to capture on c2.

```
[FEN "8/p1p2p1p/5pbp/8/qN1N4/4N2p/pr1r4/k1K1N2N w - - 0 1"]

  1. Nbc2 Bc2 2. N4c2 Rbc2 3. N3c2 Rc2 4. Nc2 Qc2 5. Kc2 h2 6. Nf2 h5 7. Nh1 h4 8. Nf2 h3 9. Nh1 h6 10. Nf2 h5 11. Nh1 h4 12. Nf2 f5 13. Nh1 f4 14. Nf2 f3 15. Nh1 f6 16. Nf2 f5 17. Nh1 f4 18. Nf2 a6 19. Nh1 a5 20. Nf2 a4 21. Nh1 a3 22. Nf2 c6 23. Nh1 c5 24. Nf2 c4 25. Nh1 c3 26. Nf2 h1=Q 27. Nh1 h2 28. Nf2 h3 29. Nh1 f2 30. Nf2 f3 31. Nh1 f2 32. Nf2 h1=Q 33. Nh1 h2 34. Nf2 h1=Q 35. Nh1

```

# Answer
> 5 votes
I can't speak to whether this satisfies the (rather awkward) constraints you've put upon the problem, but the longest I was able to find with a rather cursory search was 201 moves:

```
[FEN "6K1/pn5n/2p3Q1/P1P5/Bp5p/p5p1/pbP3pr/rk5b w - - 0 1"]

1. c4+ Kc1 2. Qh6+ Kb1 3. Qxh7+ Kc1 4. Qh6+ Kb1 5. Qg6+ Kc1 6. Qg5+ Kb1 7. Qf5+ Kc1 8. Qf4+ Kb1 9. Qe4+ Kc1 10. Qe3+ Kb1 11. Qe1+ Bc1 12. Qxb4+ Bb2 13. Qe1+ Bc1 14. Qe4+ Kb2 15. Qe5+ Kb1 16. Qf5+ Kb2 17. Qf6+ Kb1 18. Qg6+ Kb2 19. Qg7+ Kb1 20. Qxb7+ Bb2 21. Qh7+ Kc1 22. Qh6+ Kb1 23. Qg6+ Kc1 24. Qg5+ Kb1 25. Qf5+ Kc1 26. Qf4+ Kb1 27. Qe4+ Kc1 28. Qe3+ Kb1 29. Qg1+ Bc1 30. a6 Kb2 31. Qd4+ Kb1 32. Qe4+ Kb2 33. Qe5+ Kb1 34. Qf5+ Kb2 35. Qf6+ Kb1 36. Qg6+ Kb2 37. Qg7+ Kb1 38. Qb7+ Bb2 39. Qh7+ Kc1 40. Qh6+ Kb1 41. Qg6+ Kc1 42. Qg5+ Kb1 43. Qf5+ Kc1 44.Qf4+ Kb1 45. Qe4+ Kc1 46. Qe3+ Kb1 47. Qg1+ Bc1 48. Kf8 Kb2 49. Qd4+ Kb1 50. Qe4+ Kb2 51. Qe5+ Kb1 52. Qf5+ Kb2 53. Qf6+ Kb1 54. Qg6+ Kb2 55. Qg7+ Kb1 56. Qb7+ Bb2 57. Qh7+ Kc1 58. Qh6+ Kb1 59. Qg6+ Kc1 60. Qg5+ Kb1 61. Qf5+ Kc1 62. Qf4+ Kb1 63. Qe4+ Kc1 64. Qe3+ Kb1 65. Qg1+ Bc1 66. Ke8 Kb2 67. Qd4+ Kb1 68. Qe4+ Kb2 69. Qe5+ Kb1 70. Qf5+ Kb2 71. Qf6+ Kb1 72. Qg6+ Kb2 73. Qg7+ Kb1 74. Qb7+ Bb2 75. Qh7+ Kc1 76. Qh6+ Kb1 77. Qg6+ Kc1 78. Qg5+ Kb1 79. Qf5+ Kc1 80. Qf4+ Kb1 81. Qe4+ Kc1 82. Qe3+ Kb1 83. Qg1+ Bc1 84. Kd8 Kb2 85. Qd4+ Kb1 86. Qe4+ Kb2 87. Qe5+ Kb1 88. Qf5+ Kb2 89. Qf6+ Kb1 90. Qg6+ Kb2 91. Qg7+ Kb1 92. Qb7+ Bb2 93. Qh7+ Kc1 94. Qh6+ Kb1 95. Qg6+ Kc1 96. Qg5+ Kb1 97. Qf5+ Kc1 98. Qf4+ Kb1 99. Qe4+ Kc1 100. Qe3+ Kb1101. Qg1+ Bc1 102. Kc8 Kb2 103. Qd4+ Kb1 104. Qe4+ Kb2 105. Qe5+ Kb1 106. Qf5+ Kb2 107. Qf6+ Kb1 108. Qg6+ Kb2 109. Qg7+ Kb1 110. Qb7+ Bb2 111. Qh7+ Kc1 112.Qh6+ Kb1 113. Qg6+ Kc1 114. Qg5+ Kb1 115. Qf5+ Kc1 116. Qf4+ Kb1 117. Qe4+ Kc1 118. Qe3+ Kb1 119. Qg1+ Bc1 120. Kb8 Kb2 121. Qd4+ Kb1 122. Qe4+ Kb2 123. Qe5+ Kb1 124. Qf5+ Kb2 125. Qf6+ Kb1 126. Qg6+ Kb2 127. Qg7+ Kb1 128. Qb7+ Bb2 129.Qh7+ Kc1 130. Qh6+ Kb1 131. Qg6+ Kc1 132. Qg5+ Kb1 133. Qf5+ Kc1 134. Qf4+ Kb1 135. Qe4+ Kc1 136. Qe3+ Kb1 137. Qg1+ Bc1 138. Kxa7 Kb2 139. Qd4+ Kb1 140. Qe4+ Kb2 141. Qe5+ Kb1 142. Qf5+ Kb2 143. Qf6+ Kb1 144. Qg6+ Kb2 145. Qg7+ Kb1146. Qb7+ Bb2 147. Qh7+ Kc1 148. Qh6+ Kb1 149. Qg6+ Kc1 150. Qg5+ Kb1 151. Qf5+ Kc1 152. Qf4+ Kb1 153. Qe4+ Kc1 154. Qe3+ Kb1 155. Qg1+ Bc1 156. Kb8 Kb2 157. Qd4+ Kb1 158. Qe4+ Kb2 159. Qe5+ Kb1 160. Qf5+ Kb2 161. Qf6+ Kb1 162. Qg6+ Kb2 163. Qg7+ Kb1 164. Qb7+ Bb2 165. Qh7+ Kc1 166. Qh6+ Kb1 167. Qg6+ Kc1 168. Qg5+ Kb1 169. Qf5+ Kc1 170. Qf4+ Kb1 171. Qe4+ Kc1 172. Qe3+ Kb1 173. Qg1+ Bc1 174. a7 Kb2 175. Qd4+ Kb1 176. Qe4+ Kb2 177. Qe5+ Kb1 178. Qf5+ Kb2 179. Qf6+ Kb1 180. Qg6+ Kb2 181. Qg7+ Kb1 182. Qb7+ Bb2 183. Qh7+ Kc1 184. Qh6+ Kb1 185. Qg6+ Kc1 186. Qg5+ Kb1 187. Qf5+ Kc1 188. Qf4+ Kb1 189. Qe4+ Kc1 190. Qe3+ Kb1 191. Qg1+ Bc1 192. a8=Q Kb2 193. Qd4+ Kb1 194. Qb7+ Bb2 195. Qh7+ Kc1 196. Qh6+ Kb1 197. Qg1+ Bc1 198. Qd2 Rh3 199. Bxc6 Rh2 200. Bd7 Rh3 201. Bxh3

```

White plays c4+, then continually checks the black king (who alternates between shuttling back and forth between b1 and c1 with the bishop on b2, and shuttling between b1 and b2 with the bishop on c1) while maneuvering the WQ from g6 first to capture the Nh7, then the Pb4, then the Nb7, then eventually to check black at g1 and force 29...Bc1. Play then goes 30. Pa6 Kb2 and White executes a zigzag up to g7, then checks on b7 (forcing 38...Bb2 once again), then checks on h7 and zigzags back to play 47. Qg1+ and force Bc1 again, taking another 'free move' to play 48. Kf8.

This same maneuver (zigzag up to g7, check on b7 inducing Bb2, zigzag to check on g1, forcing Bc1, then take a 'free move' when Black's best play is Kb2) repeats as White plays 66. Ke8, 84. Kd8, 102. Kc8, 120. Kb8, 138. Kxa7, 156. Kb8, 174. Pa7, and 192. Pa8Q; play concludes with Qd4+, Q-b7-h7-h6+, Qg1+, and 198. Qd2 Rh3 199. Bxc6 Rg3, 200. Bd7 Rh3 201. Bxh3 stalemate.

(This problem comes out of *The Problemist*, by CJ Morse.)

# Answer
> 5 votes
Aloril has created what he calls “mobility chess” and generated up to 5-man tablebase for it. It just so happens that it generates shortest forced stalemates when there is one and there is no possible mating sequence.

Here are the extracted statistics provided for the longest forced stalemate sequences of 3, 4, and 5 unit positions.

3 man:

```
[Title "KPvK, stalemate, 42 ply"]
[StartFlipped "0"]
[FEN "8/8/8/8/8/1k6/7P/K7 b - - 0 1"]

1...Kc4 2. Kb1 Kd3 3. Kc1!! Ke4 4. Kd1 Kd3 5. Ke1! Ke3! 6. Kf1! Kf3! 7. Kg1! Kf4! 8. Kf2 Kg4! 9. Kg2! Kh4! 10. h3! Kh5! 11. Kg3! Kg5! 12. h4+! Kf5 13. Kf3!! Kf6! 14. Kf4 Kg6! 15. Kg4! Kg7 16. Kg5! Kf7 17. h5! Kg7! 18. h6+! Kf7 19. Kf5!! Kf8! 20. Kf6 Kg8!! 21. Kg6! Kh8!! 22. h7! *

```

4 man:

```
[Title "KPvKP, stalemate, 53 ply"]
[FEN "K7/8/5p2/8/8/8/1P6/5k2 w - - 0 1"]

1. b4!! f5 2. b5!! f4 3. b6!! f3 4. b7!! f2 5. b8=Q!! Kg2! 6. Qb2 Kg1! 7. Qd4! Kg2! 8. Qg4+! Kh1 9. Qf3+ Kg1!! 10. Qg3+! Kf1! 11. Ka7 Ke2! 12. Qg2 Ke1!! 13. Qe4+! Kd1 14. Qd3+ Ke1!! 15. Qe3+! Kf1!! 16. Kb6! Kg2! 17. Qe2 Kg1!! 18. Qg4+! Kh1 19. Qf3+ Kg1!! 20. Qg3+! Kf1! 21. Kc5! Ke2!! 22. Qh2! Kf3!! 23. Qh5+! Kg2!! 24. Qg4+! Kh1 25. Qf3+ Kg1!! 26. Qg3+! Kh1!! 27. Qxf2! *

```

5 man:

```
[Title "KQPvKQ, stalemate, 210 ply"]
[StartFlipped "0"]
[FEN "3q4/7Q/2K5/8/7k/8/4P3/8 b - - 0 1"]

1...Kg5!! 2. Qg7+!! Kh4! 3. Qh6+! Kg4! 4. Qe6+ Kf4!! 5. Qf7+! Ke5! 6. Qh5+! Kd4!! 7. Qg4+!! Kc3! 8. Qf3+!! Kb4 9. Qe4+ Kc3!! 10. Qe3+! Kc2!! 11. Qf3! Qa8+ 12. Kd6!! Qd8+! 13. Ke5! Qc7+ 14. Kf5! Qd7+ 15. Kf4 Qc7+! 16. Kg4! Qg7+!! 17. Kh3 Qh8+! 18. Kg2 Qg7+!! 19. Kf2! Qd4+! 20. Qe3! Qh4+! 21. Kg1 Qg4+! 22. Kf1! Qc4! 23. Qe5! Kd2! 24. Qg5+! Kd1! 25. Qd8+! Kc2! 26. Qf6! Kb3! 27. Kf2!! Qc5+! 28. Kg2!! Kb4 29. Qe6!! Kb5! 30. Kf3! Qh5+! 31. Kf4! Qh4+!! 32. Qg4! Qf2+! 33. Ke4!! Kb6 34. Qe6+! Kc7!! 35. Qc4+! Kb7! 36. Ke5! Qh2+! 37. Kd5!! Qh5+! 38. Kd6!! Qh2+! 39. Ke7! Qe5+! 40. Qe6!! Qg7+!! 41. Kd6! Qc7+! 42. Kd5!! Qd8+! 43. Ke5! Qg5+!! 44. Kd6! Qg3+!! 45. Kd7! Qg7+!! 46. Qe7! Qd4+!! 47. Ke6+!! Kc6 48. Qe8+!! Kc5 49. Qf8+! Kc6! 50. Qf3+! Kc7! 51. Qg3+! Kc6! 52. Qg2+! Kc7! 53. Qh2+! Kc6! 54. Qh1+! Kc5! 55. Qc1+!! Kb6! 56. Qb1+!! Ka7! 57. Qh7+! Ka8! 58. Qf5! Qb6+!! 59. Kf7! Qc7+! 60. Kg6! Qc6+! 61. Kg5! Qg2+! 62. Qg4!! Qd5+!! 63. Kh4! Qh1+! 64. Kg3! Qg1+! 65. Kf3! Qf1+! 66. Ke4! Qb1+! 67. Kf4! Qb4+ 68. Kf3! Qb3+ 69. e3! Qd1+! 70. Kg3! Qg1+! 71. Kf4! Qh2+! 72. Kf3! Qh1+! 73. Qg2! Qh4 74. Qg8+! Kb7! 75. Qf7+! Kc8! 76. Qf5+! Kd8!! 77. Qf8+! Kd7!! 78. Qg7+! Kc6! 79. Qg6+!! Kb5! 80. Qf5+! Kb6! 81. e4! Kc6! 82. Qe6+ Kc5 83. e5! Qd4! 84. Qf6! Kb5! 85. Qg5! Kc6! 86. Qe3! Qa1! 87. Kf4! Qa2 88. Qe4+! Kd7! 89. Qf5+! Ke8! 90. Kg5! Qb3! 91. Qg6+ Kd7 92. Qf6! Qa2 93. Kh6! Qe6! 94. Kh7 Qe7+! 95. Kg6! Qe6! 96. Kh6! Qa2 97. Kg7! Qe6!! 98. Qf7+! Qe7!! 99. Kg6!! Kd8!! 100. Qxe7+! Kxe7!! 101. Kf5! Kf7!! 102. e6+! Ke7! 103. Ke5!! Ke8!! 104. Kd6 Kd8!! 105. e7+! Ke8!! 106. Ke6!! *

```

# Answer
> 4 votes
I'm sure this problem has been posed before, but let's see how far we can get. I assume White will try to stalemate Black as quickly as possible, and Black tries to stave it off as long as possible.

```
[FEN "8/p1p1p1p1/2p5/2p5/2p5/2K5/p3P1P1/k7 w - - 0 1"]

1. Kc2 e6 2. e4 e5 3. g4 g6 4. g5 c3 5. Kc1 c2 6. Kxc2 c4 7. Kc1 c3 8. Kc2 c5 9. Kc1 c2 10. Kxc2 c4 11. Kc1 c3 12. Kc2 c6 13. Kc1 c2 14. Kxc2 c5 15. Kc1 c4 16. Kc2 c3 17. Kc1 c2 18. Kxc2 a6 19. Kc1 a5 20. Kc2 a4 21. Kc1 a3 22. Kc2

```

White needs to go back and forth between c2 and c1 with his King, but can try to move his pawns forward to speed up the process. Black just pushes his pawns one step at a time.

# Answer
> 1 votes
Here is a new record of **41 moves.** I retooled the White knight checking cycle with a new scheme.

```
[Title "me, chess.stackexchange.com 8/25/2019, White Draws"]
[FEN "6r1/p1p1p1r1/p1p1p1q1/4pN1N/4n3/7K/4N1p1/R4Nbk w KQkq - 0 1"]

1. Nhg3+ Qxg3+ 2. N5xg3+ Rxg3+ 3. Nexg3+ Rxg3+ 4. Nxg3+ Nxg3 5. Kxg3 e4 6. Kh3 e3 7. Kg3 e2 8. Kh3 e1=Q 9. Rxe1 c5 10. Kg3 c4 11. Kh3 c3 12. Kg3 c2 13. Kh3 c1=Q 14. Rxc1 e5 15. Kg3 e4 16. Kh3 e3 17. Kg3 e2 18. Kh3 e1=Q 19. Rxe1 c6 20. Kg3 c5 21. Kh3 c4 22. Kg3 c3 23. Kh3 c2 24. Kg3 c1=Q 25. Rxc1 a5 26. Kh3 a4 27. Kg3 a3 28. Kh3 a2 29. Kg3 a1=Q 30. Rxa1 e6 31. Kh3 e5 32. Kg3 e4 33. Kh3 e3 34. Kg3 e2 35. Kh3 e1=Q 36. Rxe1 a6 37. Kg3 a5 38. Kh3 a4 39. Kg3 a3 40. Kh3 a2 41. Ra1

```

---
Tags: problems, stalemate, records
---


title: How does Alphazero Respond to the QGD?

text:
# Question
Title: How does Alphazero Respond to the QGD?
I recently started reading Game Changer, the new(ish) book on Alphazero, and I'm really enjoying it. My one issue so far is that I can't find, in the book or elsewhere, games where Alphazero played the white side of 1. d4 Nf6 2. c4 e6 3. Nf3 d5, forcing a QGD with the knight placed on f3 very early. If anyone knows of any games that went this way, please let me know!

# Answer
> 5 votes
There were a select of games published played between AlphaZero and Stockfish 8, see e.g. here on chess24. Some of them were played without book and some with the TCEC opening book, which I reckon led to a bigger likelihood for the QGD to occur.

Considering that QGD itself is an opening for black, how frequently they occurred in AlphaZero's games playing the white side is mostly dependent on how compliant Stockfish was to playing such systems. As it happened and whether it was directly or by transposition, QGD structures did occur a few times, at least among the ones I can recall/find at the moment, which I will share below along with some other closely related lines that can potentially be of interest to you. Otherwise, and in particular when without a book, Stockfish seemed to favour lines more along Nimzo-Indian and Queen's Indian defense.

*Since the games tended to be quite long, I will only include a portion of the starting moves of the games and provide a direct link to each game so you can study the games in their entirety on your own.*

* **With** TCEC openings:

**Game 82 QGD Vienna variation, from move 7 off-book**:

```
 [title "TCEC openings, game 82, AlphaZero vs Stockfish 8 (draw)"]
 [fen ""]

 1.d4 e6 2.c4 d5 3.Nc3 Nf6 4.Nf3 dxc4 5.e4 Bb4 6.Bg5 b5 7.a4 c5 8.axb5 cxd4 9.Bxf6 Qxf6 10.Qxd4 Qxd4 11.Nxd4 Bc5 12.Nf3

```

**Game 85 QGD Harrwitz Attack, from move 11 off-book:**

```
 [title "TCEC openings, game 85, AlphaZero vs Stockfish 8 (draw)"]
 [fen ""]

 1.d4 e6 2.c4 d5 3.Nc3 Nf6 4.Nf3 Be7 5.Bf4 O-O 6.e3 c5 7.dxc5 Bxc5 8.a3 Nc6 9.Qc2 Qa5 10.O-O-O Be7 11.h4 a6 12.Kb1 Rd8 13.g4 dxc4 14.Rxd8+ Bxd8 15.Bxc4 Nxg4 16.Rg1 Nf6 17.Ng5 g6 18.Bd3 e5 19.h5 exf4 20.Qb3 Qc7 21.hxg6 hxg6 22.Bxg6 Kf8 23.Bxf7 Bf5 24.Ka2

```

**Game 1, Semi-Slav (nearly QGD) mainline**, Semi-Slav lines are always closely related to both Slav and QGD due to the rich transpositional lines that exist between them. From move ...12 off-book:

```
 [title "TCEC openings, game 1, AlphaZero vs Stockfish 8 (1-0)"]
 [fen ""]

 1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.Nc3 e6 5.e3 Nbd7 6.Qc2 Bd6 7.g4 Bb4 8.Bd2 Qe7 9.Rg1 Bxc3 10.Bxc3 Ne4 11.O-O-O O-O 12.Be1 b6 13.h4 Bb7 14.Ng5 Nxg5 15.hxg5 Qxg5 16.f4 Qe7 17.Kb1 c5 18.Bd3 g6 19.cxd5 cxd4 20.e4 Rac8 21.Qh2 f6 22.f5 exd5 23.fxg6 hxg6 24.Rh1 Qg7 25.Bc2 Ne5 26.Bb3

```

---

* **Without** book:

**Game 15, Semi-Slav (nearly QGD):**

```
 [title "Without opening books: game 15, AlphaZero vs Stockfish 8 (1-0)"]
 [fen ""]

 1.Nf3 Nf6 2.d4 d5 3.c4 e6 4.Nc3 c6 5.Bg5 h6 6.Bh4 dxc4 7.e4 g5 8.Bg3 b5 9.h4 g4 10.Ne5 Nbd7 11.Be2 Nxe5 12.Bxe5 Rg8 13.O-O Bb7 14.Re1 a6 15.g3 h5 16.Qc2

```

The list is by no means exhaustive, you might find more examples by browsing through all the available games.

---
Tags: opening, alphazero, queens-gambit-declined
---


# Question
Title: Minimal number of moves before castling in Chess960
As you know, in the initial position Chess960 the king lies between the two rooks. Here are the rules for castling.

For a starting position *P*, let *n*(*P*) be the minimal number of moves that White needs to legally castle kingside. How many positions are there such that *n*(*P*) = 1, *n*(*P*) = 2, and so on?

There are cases where we can castle in the first move, namely when the king on f1 and the rook on g1. There are also other extreme cases with the king on b1 and the rook on c1, so then we have to make space.

Maybe some engines can solve this question.

# Answer
Edit: This answer only deals with kingside castling; the figures have to be revised if you also consider queenside castling.

The three first steps:

**There are 90 positions where n(P)=1**

For White to be able to castle short at once, he needs to have Kf1, Rg1 in the initial position. Then there are 5 possible spots from the second rook, 3 for one bishop and 2 for the other one, and finally 3 remaining spots for the queen. The knights go to the last two spots.

**There are 100 positions where n(P)=2**

36 of them with Kf1, Ng1, Rh1: White can play 1.Nf3 or 1.Nh3 and 2.0-0

36 of them with Kg1, Nf1, Rh1: White can play 1.Ne3 or 1.Ng3 and 2.0-0

28 of them with Rg1, Nf1, Ke1: White can play 1.Ng3 or 1.Ne3 and 2.0-0

**There are 236 positions where n(P)=3** *please double-check this part*

Here are the different configurations and the number of relevant positions:

xxxxxQKR 18
xxxxxBKR 36
xxxxxRKR 18
xxxxxKQR 18
xxxxxKBR 24
xxxxKNNR 8
xxxKNNRx 6
xxxKNRNx 6
xxxKRNNx 6
xxxxKBRx 24
xxxxKQRx 18
xxxxKRBx 36
xxxxKRQx 18

Total:236

*Edit : removed 2 cases after checking the rules: the path to g1 must be open for the king (only the right-hand rook can be in the way)*

Once we reach **n(P)=4**, we cannot ignore Black's play anymore: for instance, QNRNKBBR *looks like* it should have n=5, but actually it has n=4 because of the sequence 1.f4 b5 2.Bxa7 Qxg2 3.Bxg2 Nc6 4.0-0. Counting by hand becomes too fastidious and hazardous: a software program is needed.

---

On the other hand, after clarification by the OP, I believe **7 to be the maximum** value of the function P-\>n(P).

If Black wasn't allowed to "help" we could build only 2 positions with n(P)=9; Here is one, the other is similar with RKBBNNQR on the first rank.

```
[FEN "rkqnnbbr/pppppppp/8/8/8/8/PPPPPPPP/RKQNNBBR w - - 0 1"]

```

In a series problem where White plays alone he would need 9 moves in order to castle. But since Black moves are taken into account, White actually can castle on move 7 from that diagram if the game goes something like 1.b3 d5 2.Qa3 Qe6 3.Nb2 Qxe2 4.Ned3 Qxf2 5.Bxf2 Nc6 6.Be2 0-0-0 7.0-0.
> 9 votes

---
Tags: chess-variants, castling, mathematics, chess960
---


# Question
Title: When is it a good idea to capture the fianchettoed bishop?
According to Simon Williams, from 25:10 and forwards of this stream, his opponents attempt at capturing his fianchettoed bishop with a bishop and queen battery is not a good idea "in these types of positions".

So, thus I ask: When is it a good idea? I usually go for it because I know that many players hate having to give up their fianchettoed bishop.

# Answer
> 6 votes
```
[FEN ""]
1. d4 c5 2. d5 g6 3. c4 Bg7 4. Nc3 d6 5. e4 Nf6 6. Bf4 O-O 7. Qd2 Re8 8. Be2 e6 9. Nf3 exd5 10. exd5 a6 11. O-O Bg4 12. h3 Bxf3 13. Bxf3 Qc7 14. a4 Nbd7 15. Rfe1 Bf8 16. Ne4 Nxe4 17. Rxe4 Rxe4 18. Bxe4 Re8 19. Re1 Bg7 20. b3 Be5 21. Bxe5 Rxe5 22. Bf3 Qd8 23. Rxe5 Nxe5 24. Bd1 Qf6 25. f4 Nd7 26. Qe3 Kf8 27. Bg4 Nb6 28. a5 Na8 29. Bc8 Qa1+ 30. Kh2 Qxa5 31. Bxb7 Nc7 32. Bc6 Qa1 33. Qf3 h5 34. f5 Qe5+ 35. Qg3 gxf5 36. Qxe5 dxe5 37. d6 Ne6 38. Kg3 e4 39. Kf2 Nd4 40. Ba4 f4 41. b4 cxb4 42. c5 b3 43. Bxb3 Nxb3 44. c6 Ke8 0-1

```

There are a few points here that make it a bad idea.

First and foremost, white's dark squared bishop in this pawn structure is his good bishop (and it's extremely active). While black's fianchetto'd bishop is also good, it isn't directly influencing the position until the knight on f6 moves (which you'll notice never happens in this game until his opponent mis-steps and trades knights).

Secondly, trading the kingside fianchetto'd bishop is usually good because it leaves black with dark squared weaknesses that white might be able to take advantage of and attack. Notice how Simon Williams calls Qd2 "an aggressive plan." He's already envisioning white trading bishops, and going for a kingside attack. However, in this position, white does not really have any pieces aimed towards the kingside that he can use to attack black's king. And the possible plan of h4-h5 to open up black's king falls flat in the Benoni when black is able to quickly open the center of the board with e6-exd5. If black had already played e5, then it would be entirely different.

Lastly, notice that when the pieces start to get traded off, BLACK offers to trade this bishop for white's (41:20ish). The reason here is that the position has transformed largely into an endgame, and Simon Williams discusses how he wants to get the classic good knight vs bad bishop endgame. All of white's pawns are stuck on light squares, impeding his minor piece's mobility. Whereas black has a few important dark squares his knight can jump to in the center of the board where it influences everything (e5 and d4 in particular, possibly c5 if white plays b4 cxb4).

Usually the fianchetto'd bishop is strong because the h8-a1 diagonal has a lot of juicy targets it can aim at from a distance. In this game, the diagonal never really meant anything.

# Answer
> 3 votes
Most of the reasons given by NoseKnowsAll are correct for this particular position. Put shortly, Black's bishop was a "worse bishop" and the remaining pieces leave White in a disadvantageous endgame.

Please take into account that chess decisions cannot be taken based on a fixed set of rules that applies in all situations. If that were the case, we would be able to buy a book where all such rules are listed and after studying it we would be playing at a world-class level. There are always factors which are specific to each position that can turn otherwise good-plans into bad ones and vice-versa.

Finally, I would add that the fact that some (bad) players don't like their bishop traded does not make automatically make it a good idea. By the way, how do you know they don't? See: "I don't like when my opponent trades his queen for one of my knights with no compensation". Would you do it?

# Answer
> -1 votes
Careful! He never said it was a bad idea. He said it usually doesn't work in these types of positions. Note how me chooses to play Re8 so he can keep his Bishop with Bh8. This is why it doesn't work; White is unable to get the trade.

---
Tags: strategy, bishops, captures, fianchetto
---


# Question
Title: What are the records for highest 1 year span performance rating?
I've heard that Bobby Fischer had a 2892 performance in 1971. If this is true, it's probably the highest performance, but I don't know if this is true. Does anyone have any information about this?

# Answer
> 5 votes
Given Carlsen's 2882 current rating and the fact that he also reached this rating in 2014, it seems likely that at some point he had a year with a performance rating higher than your 2892 figure. (I calculated Carlsen's 2013 performance rating as 2890 \[47 points in 69 games against an average opponent of 2757\] but it's tedious enough to calculate that I don't want to do it for every year.)

However, if you use current FIDE rules on how to calculate performance rating, Fischer's performance rating in 1971 was even higher than the number you specified.

In 1971, Fischer participated in three official matches that I know of:

Fischer - Taimanov Candidates Quarterfinal
Fischer - Larsen Candidates Semifinal
Fischer - Petrosian Candidates Final

(He also played some blitz and simul games, but I assume those don't count.)

Taimanov was rated 2620, Larsen was rated 2660, and Petrosian was rated 2640 at the times of the matches. Fischer scored 6/6 in the first two matches and 6.5/9 in the third, for a total of 18.5/21 and an average opponent rating of 2640.

18.5/21 corresponds to a fractional score of 0.88. According to FIDE regulations, this in turn means that the performance rating is 336 points higher than the opponent's average rating. 2640 + 336 = 2976 performance rating.

It's hard to say whether that's the highest ever, but it very well might not be, even setting aside powerhouses like Carlsen. Since a 100% score results in a performance rating 800 points above the average opponent, anyone whose record for a particular year consisted solely of a 100% match score against a 2200 player would have a performance rating of 3000. I'm guessing that has happened to someone at least once.

# Answer
> -1 votes
> I've heard that Bobby Fischer had a 2892 performance in 1971. If this is true, it's probably the highest performance, but I don't know if this is true. Does anyone have any information about this?

According to the Olimpbase site FIDE produced 2 rating lists covering 1971, one in July 1971 covering January 1971 through June 1971 and one in July 1972 covering July 1971 through June 1972.

According to this his ratings over this period were -

(Unofficial) January 1971 list - 2740
July 1971 list - 2760
July 1972 list - 2785

As you can see 2785 was the highest his rating ever reached. He was never anywhere near 2892.

---
Tags: rating, history
---


title: Value Of Pieces

text:
# Question
Title: Value Of Pieces
I am reading a book by Yasser Seirawan, and in it he assigns the following values to each piece:

**Pawn: 1 point**

**Knight: 3 points**

**Bishop: 3 points**

**Rook: 5 points**

**Queen: 9 points**

**King: infinite value**

Now its straightforward that the king should have infinite value, and that the queen is most valuable after the king. How was the value of each other piece arrived at? Why is a bishop less valuable than a rook? What is the reasoning behind each value?

# Answer
> 0 votes
The values are approximations of each piece's strength. The true, exact, "objective" value of each piece is unknown. For example, Fischer believed the bishop to be worth about 3.25, Kasparov back in the day thought it was about 3.15 (but he's recently changed his opinion to be closer to Fischer's). There are reasons for the hierarchy though, and why the approximations make sense:

1) First, it could be considered an axiom that a knight/bishop is roughly 3 times better than a pawn. There's no direct reason for this, it just seems to be the case. So a knight/bishop are roughly 3 points. Even though the bishop has longer range than the knight, it is limited to one colour complex, making them roughly equal.

2) Next, the rook. A good way to think about this piece is that it's like the bishop except can move on either colour square. For this reason, it's worth about 5 points. Not quite double the bishop, but clearly better.

3) Finally the queen. It's the rook and bishop combined into one piece. So instead of being worth 8 points, it's around 9. Since it unifies the strength of the rook and bishop into one force, it's generally considered slightly better than these two individual pieces.

---
Tags: point-value
---


# Question
Title: What is the average number of legal moves per turn?
For example in the first turn there are 20 possible legal moves (16 pawn moves and 4 knights moves). This number increases in the middlegame and then decreases in the Endgame.

Are there some calculations on the average? Google search seem to be focused only on "average number of moves per game". Would appreciate if somebody have some links to some scientific researches or also blog posts.

# Answer
> 8 votes
What you are looking for is called the branching factor, and I've always seen the number **35** mentioned, but I don't know what the original source is. I guess someone estimated it some 50 years ago by counting the number of moves in a number of random positions from games, and then it became "common knowledge". The number 35 is reasonable enough in practice, but of course is not exact.

In today's age of big data, it should be easy to take a game database and answer the question of what is the exact average number of moves per position in the database. I'm sure someone must have tried that already, but I haven't seen it.

# Answer
> 18 votes
Whilst acknowledging the comment by @SmallChess that this is pointless, it is also relatively straightforward to do. I analysed 2,539,871 games from a ChessBase mega database counting the number of moves for the next player to move before each move was played. I did not include the number of moves available after the final move of the game had been played. The total number of moves played was 194,389,820 (76.5 per game) and the total number of available moves was 6,039,013,721 giving an average of about 31.1 per move.

Here is an analysis of the average number of moves available for each colour at each move point for the first 100 moves of each. Move 0 is prior to the first move of each colour. It is interesting to observe that, on average, black has fewer options than white. I am not sure why this would be-hopefully, it isn't an error in the analysis (!) but I don't think it is.

# Answer
> 7 votes
The variability in number of legal moves is about the same for black & white... except for that odd little bump for white on move 7. This phenomenon demands further research!

---
Tags: statistics, mathematics, game-complexity
---


# Question
Title: Why can Stockfish give different evaluations at the same depth?
When I let Stockfish get to a certain depth (say depth 33), it gives some evaluation. Then I refresh the position (while leaving Stockfish on) and when it gets to the same depth it gives a different evaluation.

I know it uses previous analysis stored in a hash table to get to the same depth quicker the second time around, but why it can give a different evaluation puzzles me. Previous analysis should only improve search speed for a deterministic engine.

For anyone familiar with Stockfish's source code, any reasons this could be?

# Answer
> 7 votes
If Stockfish was a pure minimax/alpha-beta searcher with all leaves having a predetermined depth, your assumption that the search result should be reproducible would hold true, even with a different state of the hash table. That is because the result in minimax/alpha-beta only depends on the evaluation function, but not on the order in which the moves are searched, which only has an impact on speed.

However, in fact Stockfish is using a lot of forward pruning, reduction and extension techniques that are state/history dependent, so the results of the search of a subtree depends on the state/history with which it entered the subtree. Therefore, starting with hash table entries that influence move ordering (and can actually return a different evaluation than searching the subtree again) leads to a different result of for a search of same depth.

There is one more detail in the Stockfish case why even with pure alpha-beta search re-searching the position again would give different results. The evaluation of draws is pseudo-randomized with small fluctuation from zero in order to avoid some search artefacts in case of repetition draws, and this pseudo-random number depends on the node count of the current search. Therefore, using a different move ordering due to the hash entries would lead to different pseudo-random numbers, and hence potentially a different search result.

---
Tags: engines, analysis, stockfish
---


# Question
Title: What chess websites are worth subscribing to?
I am a member of `ICC` and I find it useful although it may be a bit pricey. In a recent question about "What types or kinds of chess players are there?", chubbycantorset pointed out a video on www.chess.com by `GM Kaidanov`. I started watching the video(s), but realized that they only show you the first few minutes unless you sign up, so what chess websites that require a paid subscription are worth it? This may be subjective, but I will limit worth it to mean: Quality, Community Size, Features, and Price.

# Answer
> 13 votes
Not a pay site, but FICS (free internet chess server) is my go-to for online chess.

Chesstempo is where I go for tactics and endgame puzzles (I think they have a subscription option, but I haven't subscribed, and so can't say for sure).

Playchess is associated with ChessBase and although I haven't tried their online service, ChessBase is an amazing program and good company--- they also sell video tutorials.

Utlimately, I'd recommend using the money you'd spend on a subscription on a good chess coach--- nothing beats that.

# Answer
> 8 votes
Chess.com offers a **free** trial for their highest membership (diamond) for a month. I highly, highly recommend trying that out. In addition to outstanding videos updated regularly by titled players on various aspects of the game, you also have a neat tactics trainer that allows you to customize what kind of tactics you want to do/how many at a time/what rating range you want/the option of timed vs untimed tactics, etc (although I *still* prefer chesstempo for tactics!). Another excellent feature of full access to chess.com is something called "Chess Mentor." I don't want to reveal much about it, but I certainly consider it the best feature on the site! (Even if you sign up for the free membership on chess.com, you can see some aspects of chess mentor, but you may find it too basic, depending on your level). Of course, the site also has a very nice opening explorer, a database of top level games, tournaments, etc.

It certainly wouldn't hurt to take a look (and try out!) at what the whole site has to offer for a month at zero cost. Only then you'll be able to judge whether its worth it to pay for the membership monthly/annually.

# Answer
> 4 votes
ChessLecture.com is amazing I won a free 15 day trial and with the TON of GM lectures on it I learned some new great opening theory that helped me win a few tournament games I havent yet subscribed but I just may.

-Update: I just renewed my membership, it is great!

# Answer
> 4 votes
https://www.chess.com Great place to play Chess, very active Chess forum, you can pay to get rid of advertisements, get unlimited access to videos and use the Tactics Trainer and Chess Mentor features of the site, for free you can still play unlimited games but can only do about 10 tactics a day and no access to Chess Mentor and videos.

https://chesstempo.com/ Best website for practicing tactics, membership is free

https://www.thechesswebsite.com/ Covers every aspect of Chess with videos and puzzles, almost free but paying can give you access to more features on the site.

http://www.chessgames.com/ Website containing active chess community and lots of Grandmaster games.

Other mentions:

https://chess-db.com/public/index.jsp

https://www.redhotpawn.com/

https://en.chessbase.com/

https://chess24.com/

https://www.365chess.com/

Chess-Playing Websites

http://www.chesscube.com/

https://www.chessclub.com/ (Internet Chess Club)

https://play.chessbase.com/en/

Hope this Helps

# Answer
> 3 votes
My brother once bought a paid membership upgrade on chessgames.com and it was interesting, the non-free features I found most useful were:

* Guess-the-move, you play some parts of historic games, while keeping score when you find good/best best move(s).
* Browse games with specific piece sacrifices or specific pieces vs pieces endgames from their databases.
* One-click button to download their databases in PGN format (\*all games from X player, XY vs Z remaining pieces endgames, sacrifices, etc).

<sub>\*you can theoretically get every game from a certain player as a free user, but it will take forever, the one-click-download-all will not be available.</sub>

It was not very cheap, but I really liked the option to download massively multiple games, I can now analyze them with Arena + chess engines and learn from these offline in my laptop when I don't find WiFi.

I would rate it 7/10 overall.

# Answer
> 3 votes
You could try Red Hot Pawn. It's free and really worth it. You can join tournaments, clans, etc.

# Answer
> 2 votes
I'm surprised nobody has yet mentioned chesspublishing.com. It has opening analysis by GM/IM rated players updated monthly, with playable javascript boards. The online search capability leaves something to be desired, but all the analysis can be downloaded to PGN and dropped into chess base.

# Answer
> 2 votes
I recently reactivated my FICS account, but I'm not fond of bullet, blitz and lightning so it might not get much of a workout.

A truly excellent website for playing is the (totally free, as in speech and beer) Lichess.org which will also let you embed it in your own site and does allow anonymous players (cheaters have a tendency to get smacked).

There are a few forums I visit, but they're generally region or software specific. Some of the others I peruse have already been listed above, though Chesscademy is worth a look (free training from US IMs and FMs). Also, The Week In Chess for news, live broadcast of games and an impressive archive of PGN. Historical PGN archives are also available from PGN Mentor.

# Answer
> 2 votes
Chess.com is a good website, but I prefer en.lichess.org. It has multiple variants you can play (KOTH, etc.), it's free.

Also it has its own game analyzer which is a very useful tool. In all other ways, it's about as good as chess.com.

# Answer
> 1 votes
ChessMoon (http://www.chessmoon.com) is the new chess server that you can enjoy playing chess with members all over the world, also serves as a social networking platform.

# Answer
> 1 votes
http://chesspuzzler.com is an interesting alternative to chesstempo. It's new but there's a spaced repetition option for free.

# Answer
> 1 votes
http://www.chess.com is pretty good. It brought me back to the game after 14 years! I loved the tactics trainer and mentor. I am sure with paid membership, one could achieve a lot more.

FICS is good too, I hear. If you are looking for Youtube subscriptions, I would recommend Powerplaychess https://www.youtube.com/channel/UCMBATpFb--uLNAODOVWvCTA. Daniel King's analyses of games are pretty insightful.

# Answer
> 1 votes
I asked for and received a refund from Chess.com. There were far too many cheaters, and they are *so* slow in finding and removing cheaters on their website. It is too expensive to have to put up with so many cheaters.

---
Tags: learning, websites
---


# Question
Title: First known computer-found error in expert chess analysis
What is the first known example of published expert chess analysis that was disproven by a computer search, with the winning player completely opposite? That is to say, a widely known published analysis by a chess grandmaster of a position with the conclusion that it was winning for one player, but later a computer search proved that actually it was winning for the other player. This comes close, but I am curious to see examples with win-to-lose reversal of opinion. To clarify, I am looking for the first time we discovered that the previously accepted analysis was wrong, and our discovery arose from a computer search.

# Answer
> 3 votes
In the early eighties, the evaluation of the two bishops vs knight endgame was changed thanks to computer-assisted analysis.

Previously, that endgame was thought to be a draw, but now we know the bishops can force a win.

I don't know if this is the earliest instance, but it's definiely a quite old one

# Answer
> 3 votes
Partial answers because this is an intrinsically difficult question, especially to prove it was the "first".

Endgame tablebases have changed the evaluations of some endgames. E.g.,

> Queen versus two bishops. This was thought to be a draw due to the existence of a drawing fortress position, but the queen can win most of the time by preventing the bishops from getting to the fortress. However, it can take up to 71 moves to force a win (Nunn 2002:290ff).

The question also asks about grandmaster analysis being incorrect, with the actual result being the opposite. This certainly has happened before simply because grandmasters are fallible humans. Example by Tim Krabbe:

```
3r2k1/4qpbp/Q4P2/8/2N5/4p3/PP4PP/5RK1 w - - 0 1

```

Black to move. With the powerful passed pawn on e3, Black is clearly winning. **26...e2 27. fxe7 Bd4+** and **White Resigns**.

This game was published as a brilliancy, and it was months before someone spotted the fatal flaw in the combination: the position after 28...e2?? is actually winning for White. I won't spoil it here, but if you're interested you can find the solution on Tim Krabbe's website. Of course, in today's world, errors like this will never get published because an engine will spot the winning move in a fraction of a second.

---
Tags: engines, analysis, grandmaster
---


# Question
Title: Is this position a forced win for Black after move 14?
In this Lichess game,

```
[FEN ""]

1.c4 e5 2.e4 d6 3.Nc3 Be6 4.Nf3 Nc6 5. d4 exd4 6.Nxd4 Nxd4 7.Qxd4 c5 8.Qd3 g6 9. Be2 Bg7 10.O-O Nh6 11.Re1 Ng4 12.Bxg4 Bxg4 13.e5 Bxe5 14.Nd5 Qh4 15. Nc7+ Kd7 16. Nxa8 Qh2+ 17. Kf1 Qh1#

```

After move 14 White is facing a serious mate threat from the Queen on h4, Bishop on g4, and Bishop on e5. White goes with 15. Nc7+ , forking the King and Rook, but ignoring the mate threat. After the rook capture, Mate in 2 was assured.

Could white have avoided this mate? By playing, say, Qg3 or h3? Or do both of these positions lead to wins for black, hence, white's strategy with 15 Nc7+ was to prolong mate and perhaps prod black into an unforced error?

# Answer
The best move would have been `16. Rxe5`, which entirely eliminates the mate threat, leaving white with a winning advantage.

```
r6r/ppNk1p1p/3p2p1/2p1R3/2P3bq/3Q4/PP3PPP/R1B3K1 b - - 0 16

```

Here, if black takes the white knight (`16. ... Kxc7`), `17. Bg5` wins the queen as `Qh5` is met with `Bd8+`.
> 18 votes

# Answer
15.g3 looks winning!

16.f4 is coming to win the Bishop on e5.
> 5 votes

# Answer
White could play 15. Bf4, covering h2 and attacking the Bishop on e5 which can't move due the pin in the e-file. But the probably stronger continuation is 15. g3 followed by 16. f4, winning the bishop on e5 and winning the game...
> 4 votes

# Answer
15.g3 followed by 16.f4 wins for White since the e5-bishop is pinned.
> 1 votes

# Answer
It is indeed a forced win for Black, partly due to White's choice to ignore the mate threat. White could respond better with 16.g3, thereby buying time and throwing Black off-guard.
> -1 votes

---
Tags: strategy, checkmate, forced-move
---


# Question
Title: King's Gambit, Wagenbach Defense 1.e4 e5 2.f4 exf4 3.Nf3 h5
Has this gambit (6.Ng5!) been played? (I only found games with 6.Ne5.) Is it any good? Is it the refutation of Black's silly 3...h5 (the Wagenbach Defense)?

```
[FEN ""]

1.e4 e5 2.f4 exf4 3.Nf3 h5 4.d4 g5 5.h4 g4 6.Ng5 f6 7.Bxf4 fxg5 8.Bxg5 Be7 9.Qd2

```

# Answer
> 6 votes
From my analysis, the line you give appears to be the best way White can play. After 9.Qd2, Stockfish 10 at depth 28 gives roughly +1. So I think it qualifies as a refutation of 3...h5.

I couldn't find any games where 6.Ng5 was played, but I did find a game that reached the same position on move 6 via transposition. The game was from 1788 (!) in the "London Casual Games" between two players named Cotter and Von Bruehl:

```
[White "Cotter"]
[Black "Von Bruehl"]
[Event "London Casual Games"]
[Date "1788"]

[fen ""]

1.e4 e5 2.f4 exf4 3.Nf3 g5 4.h4 g4 5.Ng5 h5 6.d4 {Transposing to the diagram you gave} f6 7.Bxf4 fxg5 8.hxg5 (8.Bxg5 {Is stronger, following your line}) d5 9.e5 Bf5 10.Bd3 Ne7 11.O-O Bg7 12.Bg3 Rf8 13.Bh4 Qd7 14.Nc3 a6 15.Qe2 Nbc6 16.Bf2 O-O-O 17.Na4 Bxd3 18.Qxd3 Nxe5 19.Qb3 b5 20.dxe5 bxa4 21.Qc3 d4 22.Qd3 Qb5 23.Qa3 Ng6 24.b3 Bxe5 25.bxa4 Qc6 26.Rab1 0-1.

```

---
Tags: opening, gambits, kings-gambit
---


title: Can you castle with a "ghost" rook?

text:
# Question
Title: Can you castle with a "ghost" rook?
I recently saw this mate-in-2 problem

```
[title "White to mate in 2"]
[fen "8/8/8/2B5/2p5/1kp5/8/R3K3 w - - 0 1"]

```

This was posed with the hint that the player of the White pieces was a strong player and Black was a novice. The take away was that White was offering rook odds, started the game without a rook on a1 and the rook now on a1 had started on h1.

The key was that White castles queenside with the ghost of the rook given as odds so the king moved from e1 to c1 and the rook on a1 stayed where it was. This forces Black to play c2 allowing White to play Ra3 mate.

This raises two questions:

1. Is castling with a "ghost" rook like this legal where there has never been a rook on a1 because it was given as odds at the start of the game?
2. Is castling with a "ghost" rook like this legal where there was a rook on a1 at the start of the game but it was captured before it could move?

The replayer doesn't like it. It will only allow castling with a real rook.

# Answer
The second part of the question is more straightforward, so I'll look at that first.

> Is castling with a "ghost" rook like this legal where there was a rook on a1 at the start of the game but it was captured before it could move?

Article 3.8.2 of the FIDE Laws of Chess describes how castling works:

> 3.8.2 by ‘castling’. **This is a move of the king and either rook** of the same colour along the player’s first rank, counting as a single move of the king and executed as follows: the king is transferred from its original square two squares towards the rook on its original square, **then that rook is transferred to the square the king has just crossed**.

This explicitly states that castling involves two pieces, the king and the rook, and it describes how the rook moves in this manoeuvre. If you don't have an unmoved rook on the board then you can't castle. Therefore castling with a "ghost" rook is illegal.

With this clear the first part becomes easier to answer.

> Is castling with a "ghost" rook like this legal where there has never been a rook on a1 because it was given as odds at the start of the game?

It depends on the rules of the competition or individual game, if the game is a one-off. If the rules state that apart from the initial position of the board the FIDE Laws of Chess apply then clearly it is illegal.

In the absence of such a clarification the best guide is probably the chess historian Edward Winter. In his chess notes for March 2009, note 6029 he considers exactly this question:

> **6029. Castling with a phantom rook** From Mark Thornton (Cambridge, England):
>
> ‘In rook-odds games could the odds-giver castle with the “phantom rook”? For example, if White gave the odds of his queen’s rook, could he play Ke1-c1? And, if so, were the castling rules the same as if the rook were present?’

According to Winter there is no conclusive ruling one way or the other. He quotes probably the most sensible approach from Howard Staunton on page 35 of Chess Praxis (London, 1860):

> When a player gives the odds of his king’s or queen’s rook, he must not castle (or, more properly speaking, leap his king) on the side from whence he takes off the rook, unless before commencing the game or match he stipulates to have the privilege of so doing.

There are strong feelings on both sides of the argument. Here is more from Winter:

> However, in a review of the book on pages 88-89 of the March 1890 BCM Edward Freeborough disagreed. After stating, with respect to level games, that castling should be described as a move of the king and that the king should therefore be moved first, Freeborough observed:
>
> *It follows logically that the fact of giving the odds of a rook ought not to deprive the king of his privilege of taking two steps to the right or left as his first move.*
>
> Page 36 of The British Chess Code (London, 1903) stated:
>
> *In the absence of agreement to a different effect, a player may castle (by moving his king as in ordinary castling) on a side from which, before the commencement of the game, the player’s rook has been removed, provided that this rook’s square is unoccupied and has been unoccupied throughout the game, and that the same conditions as to squares and as to the king are fulfilled which are required for ordinary castling on this side*.’
>
> The above text was quoted on page 275 of the June 1916 Chess Amateur when a revised edition of the Code was envisaged. Comments were invited, and on page 305 of the July 1916 issue ‘Simplex’ wrote:
>
> *This I think sheer nonsense. If a player gave me a rook and wanted to castle on this rook’s side, I should say, “No, you don’t, you can’t castle without a castle”. Let’s have no pretence. If a player gives a rook, let him give it totally not half. Receivers of odds are not strong players, and to see the nominal giver of odds move his king a couple of squares would be disconcerting. No; if a player gives odds let him give them without pretence.*
>
> A contrary view was expressed by W.S. Branch on pages 333-334 of the August 1916 Chess Amateur:
>
> *Re Chess Laws, page 305 (July), and as to “castling without rook”, I would say, first, that you can’t “castle the king” – the full and proper term, of which “castles” is an abridgment – without a castle. The phrase should be “moving the king as in castling”. I believe that the right of the odds-giver to move his king, once in a game, as in castling, has always been upheld since “castling” was invented (sixteenth century). It existed, as part of the “king’s leap”, long before “castling” was invented, and long before the rook was ever called a “castle”. The giving of the rook as odds should not deprive the king of any of his rights.’*
>
> Branch then gave further historical details regarding the king’s leap. By 1916, however, the practice of giving odds was disappearing, without any formal resolution of the ‘phantom rook’ question.

Winter revisits this topic in note 6035. "Castling with a phantom rook (C.N. 6029)" with some interesting anecdotes regarding castling with a ghost or phantom rook.
> 20 votes

# Answer
No, not really. Some problemists might use your case 1 as a joke, but it's not really legal. Your case 2 is certainly not legal (even if the rook had never moved).
> 11 votes

# Answer
@Remellion suggested in a comment, less than an hour ago, for a directmate joke problem in which the key is to capture a ghost rook in order to prevent ghost castling as a defense.

As such, I decided to make such a problem just for fun. This is what I came up with. The White rook "on a1 must be "captured" first to prevent the White king from casting away from the mating net.

```
[Title "me, chess.stackexchange.com 9/1/2019, Black Mates In 4"]
[FEN "r6B/1p2p3/8/8/8/3p1k1p/3P4/4K3 b - - 0 1"]

1. Ra1+! Bxa1 2. h2 Bd4 3. h1=Q+ Bg1 4. Qxg1#

```

I suppose the way these "ghost" rooks are as spectators. They are invisible, can be moved through, and can't interact with other pieces, similar to a ghost. But other pieces can choose to not interact with it by sitting on the square, and a one-time "capture" can be done at any time.

The technicality here is that since the rook is still there, and castling counts is king move. It can be moved without ever moving on its own. As such, interesting problems can be created.

An interesting concept that arises from this definition of a ghost rook is that a piece can capture two enemy pieces on the same square. If White moves a piece to a8 a Black piece can do a "double capture." The player giving the odds may retain their castling rights if they move onto the rook's square. The ghost rook can be “captured” though if an enemy piece is there.

While these rulesets can be applied to any "ghosted" piece, minus the king, the rook is the only interesting case due to the castling possibilities there are to explore.
> 6 votes

# Answer
There are no official rules regarding games with "odds", so I guess it's up to your taste for this particular case. Anyway, my first thought would be to say "No. You can't" and allowing that possibility would be making a strange twist of the rules that should be specified beforehand
> 1 votes

---
Tags: rules, odds
---


title: Go for an isolated pawn

text:
# Question
Title: Go for an isolated pawn
I am having trouble deciding whether I should allow getting an isolated by pushing d5. For instance, this is one of many such positions:

```
[FEN "rn1q1rk1/pp2bppp/2ppbn2/8/2PP4/2N2N2/PP2BPPP/R1BQK2R w KQkq - 0 1"]

```

Right away, I can tell that I control more space with such an advance, and I also force my opponent's light-colored bishop to retreat.

Furthermore, I get another open file, but still that does not convince me.
In theory, the isolated pawn should enable me to have a dangerous attack on the kingside but my bishops are not occupying any terrific squares. Another reason which deterred me from playing d5 is that this pawn would become very vulnerable.

After forcing the e6 bishop to c8, I think that I am only forcing Black to fianchetto their bishop, which would exert pressure on the isolated pawn.

All in all, I am not sure how to tell which factors outweigh the others in the push of the d5 pawn so I can decide if such move is correct or not.

# Answer
Your understanding and judgment about a couple of things is way off.

First, you really need to understand that all isolated pawns are not created equal. If it were on an open file, then you need to worry about it becoming a weakness more (frontal attack by rooks, in particular), but here, because after d5 cd; cd it is shielded by the pd6, it is hard for black to attack d5, let alone win it. Also, again, you are mistaking the famous "isolani" positions, which is an isolated d-pawn on the open file, which can often go to d5 and create k-side chances. This is not that position. This gains space, which in some types of positions can lead to an attack if the center is closed, but here, although I like d5, there are too many open lines in the middle to hope that a k-side attack will work.

I like d5 because it gains more space, and you will have the excellent d4 square for the Nf3 after you finish developing a bit more. That is a tangible and relatively permanent plus in your position.

If you do not do it now, black should play d5, and the position is closer to level. It is now, or never, and you are not losing anything on your development because black has to move the B twice also.

Positions like this typically will come down to who can seize the e-file. Even though the c-file is also open, in practice, it is not as important as the e-file. If you can double rooks, and black cannot oppose them, often due to his pieces tripping over each other in the lack of space, you will win. Also, then, and only then, you may be able to execute that k-side attack with Re3-g3 or h3.

Also, after d5 cd; cd, there is no really good square for the B to go to. c8 undevelopes it, d7 and the Q or N also want that square. f5, and Nd4 will come with tempo. g4, and white will play h3 and either gain the B pair, or at least gain luft with tempo.

Lastly, I also noticed that black's q-side will be vulnerable after the B goes to e3. For the Ra8 to move, then a6 will need to be played, and then maybe Nc4-b6 might happen. Also, if Na6-c5, black might try to secure the N with a5, and then b5 could lead to something.

All, and all, as a Master for 34 years, I really like d5.

**The following is in response to the question below. It was too long to just add in as a comment.**

First, let’s discuss the idea of Bc8 with b6 and Bb7. It is very bad for the following reasons: You are talking about spending three moves to reposition the B to b7, and you weaken c6, which white will get to soon. Nd4 supported by an eventual Rc1, and then the N will go to c6 severely cramping black. A white Nc6 will be absolutely intolerable, so you will be forced to spend yet another move to trade the Bb7 off for it. This will create a strong passed pawn for white on c6, and it will then expose the black pd6, which will then be on an open file, and possibly give white use of d5 for a piece, although there is no immediately good piece that could go there. Of course, white will not play Nc6 until he is sure that it will not simply be lost. In addition, all these moves are sure to put you way behind in development.

This Nd4-c6 idea protected by a pd5 is a very common idea, and compare it to Yusupov-Kuzmin 1981 (PGN below). Go through that game around the move 15.Ne5. The threat of e5 forced black to take drastic measures, but try to make other reasonable moves, and see just how much that N hinders black, and look at what happens when he takes it because he cannot tolerate it. Neither is a good option.

I do not like the B going to g4 because as white I am happy for you to trade it off on f3 giving me the two Bs. Also, if I do not lose a tempo playing h3 (“luft”, which is German for air, meaning you will not be able to backrank mate me later), which will probably be helpful later, that is another small plus. Chess is a game of accumulating small plusses at least when playing similarly-rated opponents. I am also a very positional player, and like closed and semi-closed positions, so that type of position is right up my alley. I am willing to make your position uncomfortable, and wait for you to crack.

This game comes from the 11/26/2008 version of ChessBase.

```
[Title "Artur Jussupow-Gennadi  Kuzmi, Moscow, URS Team Tournament-ch15 Final A Tournament, 5/16/1981"]
[FEN ""]

1. d4 Nf6 2. c4 g6 3. Nc3 d5 4. cxd5 Nxd5 5. e4 Nxc3 6. bxc3 Bg7 7. Nf3 O-O 8. Be2 c5 9. O-O Nd7 10. Bg5 cxd4 11. cxd4 Nf6 12. Qd3 b6 13. Rac1 Bb7 14. d5 Qd7 15. Ne5 Qd6 16. Nc6 Qd7 17. e5 Nxd5 18. Nxe7+ Kh8 19. Bf3 Rae8 20. Rfd1 Rxe7 21. Bxe7 Qxe7 22. Bxd5 Rd8 23. Qb3 Bxd5 24. Rxd5 Rxd5 25. Qxd5 Bxe5 26. g3 Bd6 27. Qd4+ Qe5 28. Rd1 1-0

```
> 16 votes

# Answer
While the push could result in an isolated pawn, it would saddle Black with an isolated pawn as well. Furthermore, this Black pawn would make your own isolated pawn less vulnerable than most isolated pawns. It couldn't be attacked from straight ahead and doesn't provide a nice blockade square for an enemy piece. Furthermore, the Black isolated pawn cramps its position. In the long term, your isolated pawn might be more vulnerable than Black's, but if you are going for an attack the extra space could be worth it. That doesn't mean that you *should* push the pawn here. I would probably just castle since I'm a wimp who likes to think about my own safety before worrying about storming my opponent's kingside.
> 6 votes

# Answer
It looks like a `d5` push is premature.

Keep in mind is that you have not completed development. You correctly noted that your bishops are not at terrific squares. Besides, your rooks are also not ready. Castle, develop the dark-squared bishop, position rooks. Only then consider the push.
> 1 votes

# Answer
In general, isolated pawns aren't necessarily bad. I've been studying the Alapin sicilian recently (from the black side) and I'm amazed at how much activity white has. I thought it would be very fairly easy to equalize but stockfish keeps coming up with idea after idea. Every time I think I have it beat there's some new crushing line that I missed. i recommend trying that if you want to learn about IQP. Prove that black is equal in the Alapin. Whether or not you succeed you'll learn a lot.

More specifically, the line you gave isn't a true IQP position. I often read in books the comparison of an IQP to a "battering ram" smashing its way through the opponent's structure. That's not happening here. Everything is situational.
> 1 votes

---
Tags: strategy, isolated-pawn
---


# Question
Title: If there is a winning strategy, is it for White?
We do not know, given two perfect players White and Black, whether the game would necessarily end in a draw, or necessarily end in a win (for either Black or White).

However, can we prove that if there is a winning strategy, then it is for White? In other words, can we prove that Black must either lose or draw?

# Answer
If there is such a proof, no one has found it, and I doubt very much that such a proof exists (it is hard to imagine a mathematically provable "guaranteed-draw" strategy as White). One would certainly expect White to have an advantage if anybody did, but there are some downsides to going first as well (you have to disclose information before your opponent), so it is theoretically possible that the downsides outweigh the upsides. That said, the probability of that being the case seems to be infinitesimal.
> 9 votes

# Answer
It can theoretically be proven, but not with current technology.

If you take a brute force approach, there is some difficulty due to the number of positions.

In analysis of the Shannon Number, it is suggested that the game tree complexity is at least 10^123 for games of max length 80 moves. Let's assume that it is 10^123 for the purposes of this discussion.

> 10 ^ 81 = Estimated number of atoms in the universe
>
> 10 ^ 12 = Operations per second of a terahertz processor core (your processor probably runs at about 1/300th of this speed.)
>
> 10 ^ 7 = Rounded-off seconds per year
>
> 10 ^ 12 = 1 trillion years

Let's also assume that our processors can evaluate a chess position in only 1 processor cycle.

**So, let's make every atom in the universe operate as a terahertz processor core for 1 trillion years.**

**Can we evaluate each position for 80-max length games?**

**No.**

> 10^81 x 10^12 x 10^7 x 10^12 = 10^112

We fall short to the tune of being only 0.0000000001% complete with the calculation.

With advanced pruning (throwing out bad lines and their descendants), better technology, and some crafty programming... maybe we'll see 40-max games solved in our lifetime! We can also prune out positions that we've seen before (we can arrive there via transposition), but keep in mind it will take at least a CPU cycle to determine that we've evaluated the position before!

However, this should help you see why it's so far out of reach at the moment.

**References**
> 5 votes

# Answer
In theory, chess can be "solved", since it is a "finite" game with "perfect information". More precisely, there exists a strategy such that one player has a guaranteed win, or both players have a guaranteed draw given perfect play. Here's a technical article on the basic (well, basic for those familiar with economics/mathematics) concepts of Game Theory for those interested in the specifics. **Essentially, every game which has "perfect information",** i.e. each player can see all the pieces, and is aware of all the legal moves of said pieces at all points during the game (a counterexample of a perfect information game would be a card game, where you aren't able to see your opponent's hand), \** a finite number of players and a finite number of legal moves\**, i.e. the game doesn't go on indefinitely, **then it has a guaranteed winning or drawing strategy for one of the players.**

In practice, we have neither the technology nor the intelligence (ok, maybe if all the best chess minds of today collaborated on finding the strategy, we may have sufficient intelligence required. MAYBE.) and time to do it manually.

To answer your question: Yes, there exists a winning (or drawing strategy). No, we don't know whether it is for white or for black.

Yes, chess is doomed to get solved someday. But we won't have the technology (in my opinion the only means of doing so) for it for many, many decades (hopefully even centuries) to come.
> 4 votes

# Answer
In my opinion, I think the winning strategy is within the player's mind. Because your next move will depend on your opponent's move.
> 0 votes

# Answer
It is very unlikely that black could have a forced win since any line shown as winning for black could be played as white a tempo up. For example, if 1.e4, c5 is a forced win for black then white could play 1.c4 heading for the same line reversed.
> 0 votes

# Answer
White has a slight advantage because it goes first. We're talking about 2% more wins at the grandmaster level. This slight advantage starts to level out as the game progresses. Taken to the extreme, in a perfectly played game, they're probably going to draw.
> -2 votes

# Answer
White would have the advantage of opening the game, but I would doubt there is ever a winning strategy as you suggested.
> -5 votes

---
Tags: theory
---


title: Does this trap have a name?

text:
# Question
Title: Does this trap have a name?
I can across this trap playing a bullet game and I wonder if it has a name:

```
    [FEN ""]

1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Nc3 Bc5 5.Nd5 Nxd5 6.Bxd5 Nd4 7. Ng5 O-O 8.Qh5 Nxc2+ 9.Kf1 h6 10.Nxf7 Kh7 11.Nxd8 Rxf2+

```

And now black has a checkmate in 3.

# Answer
> 10 votes
The pattern starting from `Nxf7` does not correspond to any known (opening) trap. It's to be expected as this does not really qualify as a trap for the following reasons:

1. The path up to the critical position `10.Nxf7` has major flaws, e.g. white is hanging a full knight on move `7.Ng5` (`7...Qxg5`), so objectively, white is already lost before any trap setup is reached. Therefore, this move order does not really belong to a branch of a known opening (here the Four Knights game: Italian var).
2. Opening traps usually occur when one side is baited/tempted towards a known losing variation, such as the Légal Trap. Sometimes the side attempting to set up a trap might have to make a non-optimal, nearly dubious move to force the desired variation, but (at least for most known traps) if the opponent spots the trap and plays a refutation the game remains about equal.

However, in your example, assuming black is indeed setting up a trap, white can \[\*\] simply play `11.d4` instead of falling for `11.Nxd8,` and white's completely winning as both `dxc5` and `Bxh6` are threatened and they cannot be simultaneously parried, therefore, black is lost and if anything, all this has been nothing but a last attempted tactical bait in an otherwise completely lost position.

\[\*\]: other than the fact that white can simply play `9.Kd1` instead of `Kf1` and be completely winning having also side-stepped black's combination along the `f`-file.

---
Tags: opening-traps
---


# Question
Title: Do you feel intimidated by higher rated players?
I beat this 1570 rated player (me being 1170), but the thing is that i had his rating covered by a youtube pop-up window so I didn't know he's higher rated until i finished the game. I feel like if I knew, it would have made me perform worse due to pressure. What's your thoughts of that? I think that besides good moves, there a psychological side to chess.

If you are wondering here is a link to the game: https://lichess.org/qlnj6aMS

# Answer
> 4 votes
It really matters whether you are talking about a simple blitz game, or an OTB (over-the-board) tournament game. In blitz, it really is for fun, so you should just do precisely that, and have fun. Do not worry about someone's rating. If you are really into chess, you will play so many blitz games, and you will win some, and you will lose a lot too. Some wins will be great games, and some losses will be horribly pathetic losses. Just move on to the next game. I cannot even imagine the number of losses I have had in my life, but they all combined to make me a reasonably strong player.

Now, a tournament game is another thing, so I can understand someone getting nervous; but you really do not want to think that way **if you can help it**. I certainly know that if I got a chance to play Magnus Carlsen, I know logically that I will likely lose, but at the same time, I am not at all afraid of him (really). What is the worst that can happen: The predicted result? Big deal. Even that game, I would enjoy.

That reminds me of one other related thing that I just do not understand: In 40 years of playing tournaments, and following chess closely, I have seen a lot of weak players take draws against even world champions in simultaneous exhibitions. Sure, take a draw if it is really a dead draw, but otherwise, how many times are you going to get to play someone that strong, or even an IM or weaker GM? You should play that out, and enjoy the experience, even if you lose.

Back to the subject: You just want to take your time (within reason within any time control), and play good moves. You may not play the best moves every move, but I highly recommend not being one of those people, who constantly gets into time trouble. Funny, I feel like bad clock management, and trying to play too good a move too often is what is hurting Kasparov in the exhibition Chess 960 match he is playing against Caruana in St. Louis. He should just play moves that are good, and do not lose, and hope Caruana makes a mistake first.

Lastly, confession time: For at least the first two years I played tournaments WAY back when, I literally threw up before virtually every game. It was not because of being afraid, but just general nerves; so while I did not worry about someone's rating, I do understand your potential nervousness. I would just try to put it behind you, especially since blitz means nothing. :)

I went a little beyond the scope of the question, but hopefully, the practical advice will help someone.

ONE LAST PIECE OF ADVICE: In a tournament game, NEVER treat a lower-rated player with contempt. ALWAYS play them like you would play a Master. When you do that, you get too sure of yourself, and can make mistakes. I had a period of 7 years that I did not lose a tournament game to anyone below 2100, and I believe that part of it is not taking for granted that I would win.

---
Tags: psychology
---


title: How is the threat Qxh7 relevant here?

text:
# Question
Title: How is the threat Qxh7 relevant here?
According to chess.com, "White threatens both Qxh7 and Qxf8 checkmate-Black cannot defend against both threats." Would the threat the white Queen has towards h7 be enough to have a checkmate? How is Qxh7 relevant?

# Answer
> 5 votes
The threat of Qxh7 is VERY relavant. It is as important as Qxf8 is. I shall demonstrate.

Here is your intial postion for us all to see.

```
[FEN "r1b2r1k/pppp1p1p/2n4Q/8/q7/2PB1P2/P1P3PP/R4RK1 b - - 0 1"]

```

If Black moves their rook to prevent against Qxf8 checkmate and create an escape route for the king:

```
[FEN "r1b2r1k/pppp1p1p/2n4Q/8/q7/2PB1P2/P1P3PP/R4RK1 b - - 0 1"]

1... Re8 Qxh7#

```

Black will get checkmated. This is checkmate because the White queen attacks all of the Black king’s sqaures, and it is protected, so the Black king can’t take, and no other Black units can take it.

If Black tries to defend against Qxh7#:

```
[FEN "r1b2r1k/pppp1p1p/2n4Q/8/q7/2PB1P2/P1P3PP/R4RK1 b - - 0 1"]

1... Qe4 2. Qxf8#

```

The Black king gets mates by the threat from the first varation, and this is checkmate for the same reasons. Do note that 1... f5 by Black also defends agaisnt Qxh7, but it still falls Qxf8#.

In conclusion, the threat of Qxh7 is important because Black cannot prevent either way. There is no possible way to defend against both checkmating threats. If one threat wasn’t possible, Black could defend against it easily and eventually win the game with their extra material.

In other words, if White had only one checkmating threat, and Black could easily defend that one threat, White would be losing because Black has more pieces than White.

# Answer
> 7 votes
It is very relevant since in chess, often when you have two mate threats on two separate squares, you cannot defend both.

In this case, if you defend the mate on h7, for example, with f5; then Qf8 is still mate. If you defend the QxRf8 mate by Rg8, then Qh7 is mate. That is pretty relevant.

# Answer
> 3 votes
Qxh7 is relevant because it is checkmate - note the Black King cannot take the White Queen because it is defended by the Bishop on d3.

---
Tags: analysis, checkmate, problems
---


# Question
Title: Threefold repetition in view of castling rights
In view of castling rights, an aspiring rules lawyer could ask: when does threefold repetition support a draw claim? Technical example:

```
[fen ""]
[title "Illustration of castling rights"]
[startply "13"]
[startflipped "0"]

1. e4 g6 2. b3 Bg7 3. g3 BxRa1 4. e5 b6 5. Na3 Bb7 6. Qg4 BxRh1 7. Nc4 Nc6 8. Kd1 Nb8 9. Ke1 Nc6 10. Kd1 Nb8 11. Ke1

```

The aspiring rules lawyer's question is not actually my question today. My questions today rather are these:

1. Has an arbiter ever expressed an opinion, given advice or issued a ruling regarding threefold repetition in view of castling rights?
2. Have competent persons in any chess federation ever discussed the matter?
3. Do parallel or otherwise related laws, opinions, advice, rulings or discussions by arbiters, federations or competent persons exist that indicate the principles by which such a case might be judged?

The three questions are related and answers to any or all of the three—or even *partial* answers to any of the three—would be read with interest. I seek insight into how chess authorities have approached (or would approach) such problems.

Related question here. Related answer here. FIDE's laws of chess here.

**UPDATE**

The excellent, concise, informative, well-researched answers of @BrianTowers and @TonyK, taken together, perfectly illustrate the reason the question has been asked. Both answers are recommended and, naturally, both have been upvoted by me. Ironically however, under the circumstance, neither answer can be accepted over the other, can it, for only the two answers *together* serve to illustrate the point.

Since the two answers so perfectly capture the two sides, my preference would be that further answers (if any) avoid taking sides but rather focus on the three items listed above.

**ILLUSTRATION BY @REMELLION**

Incidentally, before the question was asked, @Remillion had composed a problem position to illustrate a related point. He had originally meant the position as a joke but, since he has mentioned the position in comments in the present context, we can diagram it here.

```
[fen "B6N/1p1pp3/4pp1P/7P/7P/2p4P/1PPP2rr/R3K2k b - - 0 1"]
[title "By @Remellion: black to move; helpmate in 2"]
[startflipped ""]

```

# Answer
> 1. Has an arbiter ever expressed an opinion, given advice or issued a ruling regarding threefold repetition in view of castling rights?"

Yes, Stewart Reuben, International Arbiter and Chair of the FIDE Rules Committee has presided over progressive rationalization of the FIDE rules, and is very aware of the general questions over castling and e.p. impact on threefold repetition. I don't know if he knows of the rook-capture lacuna.

> 2. Have competent persons in any chess federation ever discussed the matter?

Apart from FIDE, members of WFCC (World Federation of Chess Composition) have certainly discussed this issue. In Fairy Chess the general principle applies that a newly minted rook is assumed never to have moved. @Remellion's problem relies on this. The rook-capture lacuna is a slightly different point, stating that original castling rights remain rather than become re-established.

Problemists also generally concur that a king can make a double hop "castling" if a rook was given as odds. I don't know if any would go as far to agree with @Brian Towers that this could happen in a non-odds composition, as it would interact pathologically with the problem convention that castling rights are assumed to be retained unless they can be proved to have been lost.

> 3. Do parallel or otherwise related laws, opinions, advice, rulings or discussions by arbiters, federations or competent persons exist that indicate the principles by which such a case might be judged?

EDIT: (thanks itub) I now have an idea what USCF opines, since their rules are now published uschess.org/content/view/7752/369. Draw by repetition is constrained by rights of castling and e.p. But the concept of "rights" is not defined in the movement rules. This is actually quite important since under FIDE, the interpretation is subtly different between castling and e.p. The paragraph which in FIDE laws contains the rook-capture hole does not appear in USCF.

(Sidebar: my initial impression of the USCF rules is quite positive. They seem fluently written, with some authorial personality (e.g. "Tournament Director Tips") and there's are some good ideas which are new to me (e.g. can only claim a draw at the beginning of your turn, any claim also implies an offer of a draw). However the first time we try to get a clear answer, about "rights" we are a little let down.)

So the FIDE rook-capture lacuna is surely just a hole, and it may be filled in the future. In the mean time, FIDE arbiters have discretion to interpret the rules using their judgement, as @TonyK stated.

In the mean time, as Brian surmised, at least one joke problem relies on specifically this point. Place both kings and two knights on an empty board so that with White to move there is a unique way to draw by repetition in 4.0 moves. (A.Buchanan, version Retros Mailing List 3/1/2019). Note that this relies on the aforementioned castling convention.
> 2 votes

# Answer
This is dealt with explicitly in article 9.2.2 -

> 9.2.2 Positions are considered the same if and only if the same player has the move, pieces of the same kind and colour occupy the same squares and the possible moves of all the pieces of both players are the same. Thus positions are not the same if:
> 9.2.2.1 at the start of the sequence a pawn could have been captured en passant
> 9.2.2.2 a king had castling rights with a rook that has not been moved, but forfeited these after moving. The castling rights are lost only after the king or rook is moved.

Neither of white's rooks move hence castling rights are not affected until the king moves.

In general provided white has not moved his king he may castle on the side on which a rook which has not moved has been captured. I believe there are even puzzles which rely on this for the solution.
> 5 votes

# Answer
This seems to be an omission in law 9.2.2.2:

> 9.2.2.2 a king had castling rights with a rook that has not been moved, but forfeited these after moving. The castling rights are lost only after the king or rook is moved.

It should read "The castling rights are lost only after the king or rook is moved, or the rook is captured." Indeed, that is how I hope an experienced arbiter would interpret it; the idea of having castling rights with non-existent rooks is absurd.
> 5 votes

# Answer
I have found a real game (link to chessgames.com) in which an arbiter denying a draw claim by threefold repetition due to the fact that Black had the right to castle in the first position.

What happened was that the position on the board was repeated three times, and Karpov was low on time. He announced to arbiter Geurt Gijssen his intention to play 26. Nb5, thus claiming a draw by threefold repetition. While Miles agreed, resulting in a draw anyhow, the arbiter denied Karpov his claim, stating that Black had the right to castle in the first position.

I have found a detailed source in the issue Virginia News Chess, 2013-#5, “The bimonthly publication of the Virginia Chess Federation," on pages 16 and 17.

I will quote the entire story here, even if a little repetitive. However, the arbiter's name I mentioned earlier was pulled from the chessgames.com comments page on the game, so it may not be accurate.

“There are other possible sources of misunderstanding. Perhaps the most diabolical example is what happened in the game Karpov-Miles, Tilburg 1986. This was the position after Karpov moved 22 Nb5. Ra4 25 Nc3 Ra8 and now, just like my opponent Justin, Karpov summoned the arbiter, declared his intention to play 26 Nb5, and claimed a draw since the position would be the same as after his 22nd and 24th turns. Miles agreed and the game ended, but in fact Karpov’s claim was incorrect. Even though the position ‘looks the same’ (all pieces on the same squares) each time, the first occurrence (the one in the diagram above) is actually a different position from the later two because Black still has the legal move 22...0-0-0 as an option. He can no longer castle after that first ...Ra8-a3-a8 foray, so the potential for play is different later, and thus not the “same position” under the rules. This could have been a real tragedy for Karpov if Miles had disputed the claim. The rules in force at the time called for a three minute penalty off the clock of a player making an incorrect claim. Karpov had less than five minutes remaining to reach move 40, perhaps even less than three minutes. He might easily have time forfeited or even been declared to have forfeited straightaway.”

```
[Title "Anatoly Karpov-Anthony Miles, Interpolis 10th, Tilburg Netherlands, 11/4/198"]
[FEN ""]
[startply "42"]

1. d4 Nf6 2. c4 c5 3. d5 b5 4. cxb5 a6 5. e3 Bb7 6. Nc3 Qa5 7. Bd2 axb5 8. Bxb5 Qb6 9. Qb3 e6 10. e4 Nxe4 11. Nxe4 Bxd5 12. Qd3 Qb7 13. f3 c4 14. Bxc4 Bxc4 15. Qxc4 d5 16. Qc2 dxe4 17. Qxe4 Qxe4+ 18. fxe4 Nd7 19. Ne2 Nc5 20. Nc3 Nd3+ 21. Ke2 Nxb2 22. Nb5 Ra4 23. Nc3 Ra8 24. Nb5 Ra4 25. Nc3 Ra8 26. Nb5

```

Also, just for fun, here is a miniature version of @Remellion’s hilarious helpmate idea.

```
[Title "me, chessstackexchange.com, 9/6/2019, Helpmate In 2"]
[FEN "8/8/8/8/8/7p/rr6/k3K1B1 w - - 0 1"]
[startflipped ""]

```

Solution:

> 1... h2 2. Bd4 h1=White Rook! 3. 0-0#!
> 4 votes

---
Tags: rules, draw, fide, castling, threefold-repetition
---


# Question
Title: What is the record for the most pawn double-steps in a professional game?
Quite simply, what is the record for the most pawn double-steps in a professional game? Drawn and won games are both considered. Computer games of any kind are not to be considered.

The most I have found, in quite a few games, is 8. For example, here is a game in which all 8 double steps occur in just 15 moves.

```
[Title "John Cochrane-Bonnerjee Mohishunder, Calcutta, 1855"]
[FEN ""]

1. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nxf7 Kxf7 5. Bc4+ Be6 6. Bxe6+ Kxe6 7. O-O Kd7 8. d4 Kc8 9. c4 Nbd7 10. Nc3 Kb8 11. f4 a6 12. a4 Ka7 13. b4 Rc8 14. Be3 Kb8 15. a5 c5 16. b5 Ka7 17. d5 g6 18. Qb3 Bg7 19. Rfb1 Rb8 20. b6+ Ka8 21. Nb5 Ne8 22. Ra2 Rf8 23. Na7 Ndf6 24. Nc6 Qd7 25. Nxb8 Kxb8 26. e5 Ng4 27. e6 Qe7 28. Kh1 Qh4 29. g3 Qh3 30. Bg1 g5 31. Qa4 Nef6 32. e7 Rc8 33. fxg5 Ne4 34. Rg2 Nc3 35. e8=Q Nxa4 36. Qxa4 Rf8 37. Re1 Be5 38. Qb3 Kc8 39. Qd3 Kd7 40. Rf1 Ke7 41. Rxf8 Kxf8 42. Qf5+ Kg7 43. Qd7+ Kg6 44. Qxb7 Bd4 45. Bxd4 cxd4 46. Qc6 d3 47. Qxd6+ Kxg5 48. Qf4+ Kg6 49. Qe4+ Kg7 50. Qxd3

```

# Answer
> 2 votes
I found a game with 12 double-steps on chessgames.com

```
[Title "Alexandru Sorin Segal-Karl-Heinz Podzielny, Dortmund, Dortmund Germany, 1980"]
[FEN ""]

1.d4 Nf6 2.c4 c5 3.d5 e6 4.Nc3 exd5 5.cxd5 d6 6.e4 g6 7.f4 Bg7 8.Nf3 O-O 9.Be2 Re8 10.Nd2 a6 11.a4 Nbd7 12.O-O Rb8 13.a5 Qc7 14.Qc2 b5 15.axb6 Nxb6 16.Bf3 c4 17.Kh1 Bh6 18.Ne2 Qc5 19.b4 cxb3 20.Qxb3 Qc7 21.Qd3 Bd7 22.Rxa6 Nbxd5 23.Qd4 Bb5 24.Ra7 Qc5 25.Qxc5 dxc5 26.exd5 Bxe2 27.Bxe2 Rxe2 28.d6 Bf8 29.f5 gxf5 30.Ra6 Rd8 31.Nc4 Re4 32.Ne3 Rxd6 33.Ra8 f4 34.Nf5 Rd5 35.g4 fxg3 36.Nxg3 Re8 37.Ra2 Bg7 38.Nf5 Kf8 39.Nxg7 Kxg7 40.Rg2+ Kf8 41.Bh6+ Ke7 42.Bg5 Rxg5 43.Rxg5 Rg8 44.Rxc5 Rg6 45.Rc8 Nd5 46.Ra8 Rf6 47.Rb1 Rf5 48.Rh8 h5 49.Re1+ Kf6 50.Rh6+ Kg7 51.Rd6 Kh7 52.Ra6 Nc7 53.Raa1 Ne6 54.Rf1 Rxf1+ 55.Rxf1 Kg6 56.Kg2 Nd4 57.Ra1 Kg5 58.Ra5+ f5 59.h4+ Kf4 60.Ra6 Ne2 61.Rg6 Nd4 62.Rg8 Nc6 63.Rg5 Ne5 64.Kh3 Nd3 65.Rxh5 Nf2+ 66.Kg2 Kg4 67.Rh8 Nd3 68.Rg8+ Kxh4 69.Kf3 Kh5 70.Re8 Kg5

```

# Answer
> 4 votes
This is clearly contrived, but it was an actual tournament game so it wins that record. :)

```
  [Title "Danny Jazmati-Marcel Harff, NRW-ch U12, 2002"]
  [FEN ""]

1. a4 a5 2. b4 b5 3. c4 c5 4. d4 d5 5. e4 e5 6. f4 f5 7. g4 g5 8. h4 h5 9. Ra2 Rh6 10. Rh3 Raa6 11. Bd2 Be7 12. Bc3 Bf6 13. Nd2 Ne7 14. Nb3 Ng6 15. Ne2 Bb7 16. Kf2 Nd7 1/2-1/2

```

---
Tags: pawns, records, master-games, famous-games, double-step
---


# Question
Title: Why I did not see the first-mover advantage in my game history?
I have played over a thousand blitz games at chess.com and here are the results:

I failed to notice any obvious difference between white and black. In other word, I do not see the the first-mover advantage in my game history at all.

1. What are the possible reasons that the the first-mover advantage is not reflected in my game history?
2. If playing white does not give me an advantage, should I play the Saragossa opening and play as if I am playing black (Slav with one extra tempo, Caro-Kann with one extra tempo, etc.) when I am actually playing white?

# Answer
I thought you'd be playing something quiet like the London System. It explains perfectly well why your win rates with Black and White match.

Not because the London is not "sound and solid". It is. But *too* solid.

Solid is fine as Black when the main aim is to equalize White's first-move advantage.

However, if you are playing White yourself, you can strive for a little more, namely maintaining that slight advantage. But this is not something that the London is known for. You basically play the same way as if you were Black. Thus, you cannot really expect much different results, can you?

In short, **you don't experience the first-move advantage because you play openings that don't try very hard to maintain it**.

From this it does *not* follow that the advantage does not exist - it just "happens" in other openings (and since these are more popular, they have a bigger influence on the average).

It also doesn't mean that you should stop playing the London. After all, it's not *worse* than your Black openings and they are fine, too.
> 2 votes

# Answer
The advantage White gets in a game is so small that it becomes completely irrelevant at low levels. What is the point of having such edge on your opponent if you at least are going to make an inaccuracy in the opening or middlegame? Furthermore, in blitz games that small advantage is probably negligible since a greater deal of mistakes are made.

My online rating in lichess is today close to 1700 and I see this in my games all the time. I do OK until a certain move (or later on) but due to something I cannot understand, I lose that +1 advantage I had accomplished before.

All in all, I do not think you should expect to have a greater percentage of wins as White unless you are above 2000 because below that, mistakes make the players constantly lose the upper hand they managed to acquire. At higher levels, masters are more likely to capitalize on small advantages and turn the game into a win.
> 11 votes

# Answer
Maths64's answer is fine. I would like to add: "Don't change your opening repertoire based on some silly irrelevant statistics! Play what feels more comfortable with you"

It could be the case that you faced stronger players more often as White. It could also be the case that you made some random mistakes more often as White due to pure chance (or maybe because you had one more attempt to do them!)

I would therefore be careful about taking conclusions from statistics. If you want to know where you are making mistakes, take a handful of your games and analyze them
> 2 votes

---
Tags: statistics, advantage
---


title: Computers and draws

text:
# Question
Title: Computers and draws
Engines really push for a win in a dead-draw middlegame position, unlike humans who may agree on a draw. Why is that happening?

# Answer
If an engine continues to play on in a drawn position, the reason is because it simply hasn't been given the heuristic to offer a draw in a dead drawn position. There are a couple of reasons a programmer may not program in such a heuristic:

1) Suppose an engine calculates that the game is a forced draw at depth 30, but to a human (or much weaker engine) the position is very complicated and not at all drawn. It wouldn't make sense to offer a draw here.

2) Making a heuristic that assesses whether a position is "dead drawn" may be non-trivial. What constitutes "dead drawn" versus an equal position? Quantifying this could be tricky.
> 3 votes

# Answer
It is not so much that engines "push for a win in a dead drawn position." Instead, they simply continue to play the most accurate moves--because they are engines and lack the volition to do anything else by virtue of their programming. Since it can be difficult for a human to continue to find the accurate drawing moves even in an equal position, especially when time trouble is a factor, the human simply feels as if the engine is pushing for a win.
> 1 votes

# Answer
The simple answer is that most engines are not programmed to offer a draw, nor to accept draw offers when made. Those that do are the rare exceptions. Furthermore, for such an engine to make/accept a draw offer, it must judge the position to be equal, which might not correspond with the human intuition for what a drawn position is.
> 1 votes

---
Tags: engines, draw
---


# Question
Title: Software with support for Database with opening analysis
I'm looking for a software tool that will:

1. **Engine Support**. For analysis suggestions.

* **Support for software evaluation of the moves**. I guess this is optional, although I've seen this feature in popular websites where they give a weight on each move. +1.5, -.8, etc, but what is needed is at least give an arbitrary/subjective weight/evaluation on them with a comment as a justification (just an Idea) as comparison.
2. **Organize the moves variations (from the Opening) with trees**. The only tool that I've seen that has this feature is chessmaster series, other tools have a similar approach but not with trees but a list of the next "registered" variations/moves, this will be acceptable as well, although a tree will be definitely optimal

* **Rearrange variations on the tree by weight**. Optional. Also seen on chessmaster but in chessmaster it is shown as a 3 star rating on the move so if the moves/variations have weights on them, those can be used to list them in order under the tree.
3. **Support for opening books and easy way to expand them**. I want to be able to add a fairly complete Opening book like "olympiad.abk" and expand it, with new options in the openings and add comments on the different variations.

I've analyzed several tools like the ones I mentioned and chess.com, arena, lichess.org and seeing some others, and I can see that these features exist but I'm thinking that no one has them all.

Do you know any tool that has all these features? Or can you think of something even remotely similar?

# Answer
> 1 votes
I found a software that complies with the specifications, at least most of them, it is pretty good and personally I really liked it, its name is CHESS POSITION TRAINER and is a paid software. Thank you everybody.

---
Tags: opening, engines, software
---


title: Candidates tournament

text:
# Question
Title: Candidates tournament
Why not allow the winner of the Women's world championship and the winner of the Junior world championship to join the candidates tournament? Their rating is lower than the top 10 players but I mean they are both champions . Also this would give extra motive for women to play chess since the winner of the Women's world championship would have a chance to play for the World Championship.

# Answer
(this is my opinion, this is a purely opinion-based that some would say should be closed but I prefer to just give my answer)

It seems unfair and discriminatory to allow someone into the Candidates just because they are a woman or junior. The recent winners of both championships are also so far off the level of the Candidates that they just wouldn't belong there, and they would take the place of two players who would have qualified using the existing criteria.

All the ways of qualifying for the Candidates are open for everybody, man or woman, young or old. If the Women's champion wants to qualify for the Open championship, she can just try to qualify like everybody else.
> 7 votes

# Answer
This is not exactly the same thing, but on chess.com, they have allowed the women and the junior speed chess champion to be seeded into the open tournament. Well, the two women, who have played, Hou Yifan, and Elena Danielian have both been crushed by record scores, 27.-2.2 and 27-2 respectively.

The other day, Wei Yi got destroyed by Maxime Vachier-Lagrave 21-10.

In either case, and frankly, especially with the women, it would not be competitive. If you can get in on your strength of play, fine; but they should not be given free entry based on winning some other event. All this does is take away a slot from a more-deserving candidate.
> 3 votes

---
Tags: tournament, world-championship, candidates, women
---


# Question
Title: Is there any position where not promoting (illegally) would be the best move?
Is there any position, where moving a pawn to last rank but not promoting it to any piece would be the best move?

By the way, I know this is an illegal move. Assume it is legal.

**Edit:** Now we have a nice answer from Dag Oskar which ends with stalemate. That's good. But I wonder, if there is winning position, winning by not promoting, and the only winning move is not promoting.

**Edit #2:** I think a winning position is impossible, as this seems to be occurable when opponent stalemates with promotion. If opponent is not stalemating, then there is no point of not promoting anyway. But if opponent stalemates with a knight, then bishop or rook doesn't stalemate, and etc. It's impossible to have a position where knight, bishop and rook stalemates. So, in every such position, there will be a correct promotion. Not promoting won't be the best move anyway.

Therefore, I'm accepting the answer.

**Edit #3:** Rosie F's answer demonstrates that it's possible to win with a 'not promoting move'. It's very entertaining to see it's possible.

# Answer
> 24 votes
The Matt Bengtson problem Prof. Elkies mentions is:

```
[Title "Matt Bengtson, Chess Braintwisters (Burt Hochberg), no. 103. White to move & draw."]
[FEN "4kn2/3p1pPp/4pPpK/6P1/8/2p5/1b6/8 w - - 0 1"]

```

> The start of the solution-line can't be shown in PGN as White's 1st move is illegal: 1. g8=Black queen Qg7+ (anything else stalemates White) 2. fxg7 c2 3. g8=Q c1=Q 4. Qxf7+ Kd8 5. Qe8+ Kc7 6. Qc8+ Kb6 (Kd6 7. Qc5+) 7. Qc6+ Ka7/Ka5 8. Qb7/Qb5, drawing. White's queen is then taken for stalemate. Solution line taken from Chess Braintwisters.

However, the problem is actually cooked with a win for Black starting with “3... f6!”, and there is no stalemate for White. The solution and the cooking line can be played over on the Schwalbe Problem Database.

---

(This is in answer to a comment by Prof. Elkies to Dag Oskar Madsen's answer, but, it seems, the syntax that activates the PGN-viewer in answers doesn't do so in comments.)

A similar oddity from the same book:

```
[Title "John Beasley, EBUR, 1996. White to move & win."]
[fen "5r1K/2k1P3/3N1Bqp/N2Q1B1P/8/8/8/1R6 w - - 0 0"]

```

This problem was reprinted as no. 107 in Burt Hochberg's *Chess Braintwisters*.

> White is in check, and his only reasonable move is to capture on f8 (1. Qg8? Qxg8#). But 1. exf8=R allows stalemate after 1. ... Qg7+ because the new rook guards d8 after 2. Bxg7. Similarly, 1. exf8=N guards d7 allowing 1. ... Qh7+ and stalemate, and 1. exf8=Q/B guards d6 allowing 1. ... Qg8+ and stalemate. The answer is 1. exf8! (no promotion). Now 1. ... Qg7+ 2. Bxg7 releases d8; 1. ... Qh7+ 2. Bxh7 releases d7; 1. ... Qg8 2. Qxg8 releases d6. 1. ... Qxf6+ destroys the stalemate at once, and White wins. Solution line and discussion taken from Chess Braintwisters.

The is also viewable on the same site as the other problem.

# Answer
> 28 votes
Here is an example:

```
[fen "8/4P3/8/4p1p1/2p3Pp/p4p1K/k1p2P1P/8 w - - 0 1"]

```

`1. e8` leads to stalemate next move, while all legal promotions lose to `1... c1=Q` followed by `2... Qf1#`.

# Answer
> 5 votes
Here's another problem where White to move loses, but moving a pawn to the 8th rank and not promoting would (if it were legal) draw.

"By the 19th century \[...\] it was thought that promotion should give the maximum possible advantage. It was claimed that in some cases the best move would be to remain a pawn, and Kling composed a position to show this:

```
[Title "Josef Kling"]
[fen "r7/1Pp5/2P3p1/8/6pb/4p1kB/4P1p1/6K1 w - - 0 0"]

```

If 1 bxa8=any piece, 1 ... gxh3 2 any h2#, but if the pawn on a8 remains a pawn then 1 ... gxh3 is stalemate." - David Hooper & Kenneth Whyld, *The Oxford Companion to Chess*, 1st ed. (1987) pub. OUP, s.v. promotion (slightly adapted). Dag Oskar Madsen's problem has the same tempo (not sure of the correct term here) as Kling's: White's only mobile unit is the pawn; promotion to any piece enables Black to #2, whereas by making the pawn immobile White immediately stalemates himself.

If Black does not take White’s bishop. then White will play 2. Bxg2 and achieve a fortress position, thereby drawing the game.

# Answer
> 4 votes
In a sense, promoting illegally counts as not promoting. If it isn’t legal under chess law, it officially never happens at all. There are many types of such promotion. I shall give examples of almost all of them. There are no queen problems because there are no known correct problems where White draws by promoting to a Black queen, much less winning by doing so.

**Types Of Illegal Promotion**

1. King
2. Pawn
3. Pawn, But Promoting Later
4. Enemy king
5. Enemy pawn
6. Enemy knight
7. Enemy bishop
8. Enemy rook
9. Enemy queen

All of the source links direct to pages in the Die Schwalbe Chess Problem Database.

**King**

```
[Title "M. Frisbee & Palmer Gunkel Keeney, Pittsburgh Gazette Times 1914, Mate In 2"]
[FEN "5R2/3P4/4k3/8/3K4/8/8/8 w - - 0 1"]

```

Solution:

> 1. d8=WK Kd6 2. Rf6#

Source

**Enemy King**

```
[Title "Karl Arthur Leonid Kubbel, 1941, Mate In 2"]
[FEN "8/4P1Q1/2P5/8/8/6Pk/5P2/7K w - - 0 1"]

```

Solution:

> 1. e8=BK Kd8 2. Qd7##

Source

Additionally, here is another joke problem has castling on the enemy rank.

```
[Title "Andrew Buchanan After Anonymous, PDB Website 1/15/2019, Mate In 3 Without Queening A Pawn"]
[FEN "2k5/P3P3/P4P2/3P4/3B4/8/8/8 w - - 0 1"]

```

Solution:

> 1. e8=K Kc7 2. a8=R Kd6 3. 0-0-0#

Source

**Pawn**

```
[Title "Samuel Loyd, American Chess Magazine 12/1898, Mate In 3"]
[FEN "N1Br4/2Pb1P2/3k4/1P2R3/1P2K3/B7/8/8 w - - 0 1"]

1. cxd8! Bf5+ 2. Rxf5 Ke7 3. f8=Q#
(1. cxd8=Q/R? stalemate!)
(1. cxd8=B? Bf5+ 2.  Rxf5 stalemate)
(1. cxd8=B? Bf5+ 2. Kd4? Bxc8!)
(1. cxd8=N? Bc6+ 2. bxc6 stalemate!)
(1. cxd8=N? Bc6+ 2. Kd4? Bxa8!)

```

Source

Even more amazingly, here is a problem in which the best move for both sides is promotion into a pawn.

```
[Title "Peter Wong & Geir Sune Tallaksen Østmoe, Matplus.net Forum 11/12/17, Black Moves And White Wins"]
[FEN "5qnk/3pPB2/1p1p1N2/1pbK1NP1/1p1pP3/1P1P4/6p1/7R b - - 0 1"]
[startflipped ""]

1. gxh1! exf8! {White easily wins with an extra piece}

```

Source

Lastly, here is a classic by Thomas R. Dawson in which white promotes to a pawn three times!

```
[Title "Thomas R. Dawson, The Chess Amateur 1913, White Draws"]
[FEN "6K1/6PP/3p2PP/3P1ppp/8/ppp5/qrp5/1rk5 w - - 0 1"]

1. Kh8 Kd2 2. g8 Re1 3. g7 Re6 4. dxe6 Rb1 5. e7 b2 6. e8 Qxg8+ 7. hxg8 null 8. h7 null {Stalemate}

```

Source

**Pawn, But Promoting Later**

```
[Title "Ado Kraemer, Deutsche Schachblätter 1949, Mate In 3"]
[FEN "7K/5P2/6pp/6pk/6pr/6pb/8/8 w - - 0 1"]

```

Solution:

> 1. f8 Bf1 2. f8=Q and Kh7 ~ 3. Qxh7# or 1... g2 2. f8=N & Sd7/h7 ... 3. Nf6#

Source

**Enemy Pawn**

```
[Title "James Malcom, PDB Website 3/4/2020, Mate In 2"]
[FEN "1k1K3r/3Q2P1/1N6/8/8/8/8/8 w - - 0 1"]

```

Solution:

> 1. gxh8=BP h7,h6 (Pawns are allowed to do a double step on their first move) 2. Qc7#

Source

**Enemy Knight**

```
[FEN "8/5RPk/6N1/6K1/8/8/8/8 w - - 0 1"]

```

Solution:

> 1. g8=BN#

**Enemy Bishop**

```
[Title "James Malcom After Thomas R. Dawson, PDB Website 3/5/2020, Mate In 2"]
[FEN "6B1/2Q2P2/k7/8/K7/8/8/8 w - - 0 1"]

```

Solution:

> 1. f8=BB B~ 2. Bc4#

Source

**Enemy Rook**

```
[Title "Noam D. Elkies, Outrageous Chess Problems 2005, Mate In 2"]
[FEN "5brk/5Pp1/6K1/6N1/8/8/8/8 w - - 0 1"]

```

Solution:

> 1. fxg8=BR B~ 2. Nf7#

Source:

---
Tags: chess-variants, problems, pawn-promotion
---