CCLR Monday Morning QB

[MikeB]

CCLR flashback to 2006:

so what would you play here....

[d]8/1P6/4p3/4k1p1/1R3p2/5K1P/1P2p1r1/8 b - - 0 49


[pgn]
[Event "CCRL 40/40"]
[Site "CCRL"]
[Date "2006.04.26"]
[Round "18.1.43"]
[White "Aristarch 4.50"]
[Black "Junior 9"]
[Result "0-1"]
[ECO "B44"]
[Opening "Sicilian defence"]
[PlyCount "98"]
[WhiteElo "2598"]
[BlackElo "2681"]

1. e4 {0s} c5 {0s} 2. Nf3 {0s} Nc6 {0s} 3. d4 {0s} cxd4 {0s} 4. Nxd4 {0s} e6
{0s} 5. c4 {0s} d6 {0s} 6. Nc3 {0s} Nf6 {0s} 7. Be2 {0s} Bd7 {0s} 8. Be3
{+0.54/13 91s} Be7 {+0.72/17 71s} 9. O-O {+0.57/12 13s} O-O {(a6) +0.69/19
186s} 10. f4 {+0.51/13 142s} a6 {+0.66/18 175s} 11. Nb3 {(Nxc6) +0.50/12 54s}
Qb8 {(Qc7) +0.59/18 135s} 12. Qe1 {(Bf3) +0.67/12 98s} b5 {(a5) +0.54/18 99s}
13. cxb5 {(c5) +0.91/11 8s} axb5 {-0.12/15 38s} 14. Bxb5 {(Bf3) +0.78/11 9s}
Nb4 {(Nxe4) -0.01/17 103s} 15. Bxd7 {+0.40/14 58s} Nc2 {-0.10/16 24s} 16. Qe2
{+0.07/16 167s} Nxa1 {-0.02/16 59s} 17. Bc6 {+0.10/15 28s} Nxb3 {-0.13/17 29s}
18. Bxa8 {+0.05/16 96s} Qxa8 {(Na5) -0.26/17 85s} 19. axb3 {-0.03/16 349s} Nxe4
{-0.27/17 58s} 20. Bd4 {(b4) -0.03/15 50s} Bf6 {(d5) -0.75/16 46s} 21. Qe3
{(Qd1) +0.19/13 15s} d5 {(Bxd4) -0.62/18 54s} 22. Nxe4 {+0.05/14 25s} Bxd4
{-0.61/19 63s} 23. Qxd4 {-0.05/15 17s} dxe4 {-0.55/19 87s} 24. Rd1 {-0.05/15
58s} Rb8 {(Rc8) -0.60/18 142s} 25. b4 {-0.17/13 21s} h6 {(h5) -0.63/18 96s} 26.
Re1 {-0.14/12 10s} f5 {-1.09/18 195s} 27. h3 {(Qe5) -1.07/15 254s} Rd8 {(Qd5)
-1.05/16 82s} 28. Qb6 {-0.90/14 43s} Qd5 {-1.08/17 95s} 29. Re3 {-0.75/14 45s}
Kh7 {-1.25/16 57s} 30. Rg3 {(b5) -0.66/14 23s} Rd7 {(Qd4+) -0.73/17 85s} 31.
Kh2 {(Qb8) -0.55/15 46s} Rb7 {(Qd6) -0.70/17 48s} 32. Qc5 {-0.74/16 35s} Qd7
{-0.76/18 46s} 33. Qf8 {-0.77/17 108s} Qe7 {(Rc7) -0.99/19 74s} 34. Qxe7
{-0.53/15 11s} Rxe7 {-0.95/22 36s} 35. Rc3 {(Rb3) -0.72/16 73s} Rb7 {-0.95/20
39s} 36. Rc4 {-0.72/15 46s} g5 {-1.17/21 71s} 37. fxg5 {-0.89/15 62s} hxg5
{-1.12/20 43s} 38. Kg1 {-0.93/15 64s} Kg6 {-1.20/21 57s} 39. Kf1 {(Kf2)
-1.26/16 434s} Kf6 {(Kh5) -1.41/23 86s} 40. Ke2 {-0.84/15 82s} Ke5 {-1.54/22
69s} 41. Ke3 {-1.03/15 112s} f4+ {-1.49/21 82s} 42. Ke2 {-1.34/15 58s} Rd7
{-1.51/21 67s} 43. b5 {(Rc5+) -1.43/15 87s} e3 {-1.81/19 54s} 44. Rb4 {-1.46/16
213s} Rd2+ {-2.77/19 22s} 45. Kf1 {-1.46/16 45s} Rd1+ {(e2+) -3.37/20 36s} 46.
Ke2 {-1.46/2 0s} Rg1 {-3.37/20 36s} 47. b6 {-1.69/16 103s} Rxg2+ {-3.67/20 72s}
48. Kf3 {-1.83/16 57s} e2 {(Rf2+) -3.97/19 33s} 49. b7 {(Re4+) +1.24/15 38s}
e1=N# {-327.66/3 0s} 0-1[/pgn]

[bob]

CCLR flashback to 2006:

so what would you play here....

One thing is for sure, you don't need a computer to spot the under-promotion and mate on the move.

[d]8/1P6/4p3/4k1p1/1R3p2/5K1P/1P2p1r1/8 b - - 0 49


[pgn]
[Event "CCRL 40/40"]
[Site "CCRL"]
[Date "2006.04.26"]
[Round "18.1.43"]
[White "Aristarch 4.50"]
[Black "Junior 9"]
[Result "0-1"]
[ECO "B44"]
[Opening "Sicilian defence"]
[PlyCount "98"]
[WhiteElo "2598"]
[BlackElo "2681"]

1. e4 {0s} c5 {0s} 2. Nf3 {0s} Nc6 {0s} 3. d4 {0s} cxd4 {0s} 4. Nxd4 {0s} e6
{0s} 5. c4 {0s} d6 {0s} 6. Nc3 {0s} Nf6 {0s} 7. Be2 {0s} Bd7 {0s} 8. Be3
{+0.54/13 91s} Be7 {+0.72/17 71s} 9. O-O {+0.57/12 13s} O-O {(a6) +0.69/19
186s} 10. f4 {+0.51/13 142s} a6 {+0.66/18 175s} 11. Nb3 {(Nxc6) +0.50/12 54s}
Qb8 {(Qc7) +0.59/18 135s} 12. Qe1 {(Bf3) +0.67/12 98s} b5 {(a5) +0.54/18 99s}
13. cxb5 {(c5) +0.91/11 8s} axb5 {-0.12/15 38s} 14. Bxb5 {(Bf3) +0.78/11 9s}
Nb4 {(Nxe4) -0.01/17 103s} 15. Bxd7 {+0.40/14 58s} Nc2 {-0.10/16 24s} 16. Qe2
{+0.07/16 167s} Nxa1 {-0.02/16 59s} 17. Bc6 {+0.10/15 28s} Nxb3 {-0.13/17 29s}
18. Bxa8 {+0.05/16 96s} Qxa8 {(Na5) -0.26/17 85s} 19. axb3 {-0.03/16 349s} Nxe4
{-0.27/17 58s} 20. Bd4 {(b4) -0.03/15 50s} Bf6 {(d5) -0.75/16 46s} 21. Qe3
{(Qd1) +0.19/13 15s} d5 {(Bxd4) -0.62/18 54s} 22. Nxe4 {+0.05/14 25s} Bxd4
{-0.61/19 63s} 23. Qxd4 {-0.05/15 17s} dxe4 {-0.55/19 87s} 24. Rd1 {-0.05/15
58s} Rb8 {(Rc8) -0.60/18 142s} 25. b4 {-0.17/13 21s} h6 {(h5) -0.63/18 96s} 26.
Re1 {-0.14/12 10s} f5 {-1.09/18 195s} 27. h3 {(Qe5) -1.07/15 254s} Rd8 {(Qd5)
-1.05/16 82s} 28. Qb6 {-0.90/14 43s} Qd5 {-1.08/17 95s} 29. Re3 {-0.75/14 45s}
Kh7 {-1.25/16 57s} 30. Rg3 {(b5) -0.66/14 23s} Rd7 {(Qd4+) -0.73/17 85s} 31.
Kh2 {(Qb8) -0.55/15 46s} Rb7 {(Qd6) -0.70/17 48s} 32. Qc5 {-0.74/16 35s} Qd7
{-0.76/18 46s} 33. Qf8 {-0.77/17 108s} Qe7 {(Rc7) -0.99/19 74s} 34. Qxe7
{-0.53/15 11s} Rxe7 {-0.95/22 36s} 35. Rc3 {(Rb3) -0.72/16 73s} Rb7 {-0.95/20
39s} 36. Rc4 {-0.72/15 46s} g5 {-1.17/21 71s} 37. fxg5 {-0.89/15 62s} hxg5
{-1.12/20 43s} 38. Kg1 {-0.93/15 64s} Kg6 {-1.20/21 57s} 39. Kf1 {(Kf2)
-1.26/16 434s} Kf6 {(Kh5) -1.41/23 86s} 40. Ke2 {-0.84/15 82s} Ke5 {-1.54/22
69s} 41. Ke3 {-1.03/15 112s} f4+ {-1.49/21 82s} 42. Ke2 {-1.34/15 58s} Rd7
{-1.51/21 67s} 43. b5 {(Rc5+) -1.43/15 87s} e3 {-1.81/19 54s} 44. Rb4 {-1.46/16
213s} Rd2+ {-2.77/19 22s} 45. Kf1 {-1.46/16 45s} Rd1+ {(e2+) -3.37/20 36s} 46.
Ke2 {-1.46/2 0s} Rg1 {-3.37/20 36s} 47. b6 {-1.69/16 103s} Rxg2+ {-3.67/20 72s}
48. Kf3 {-1.83/16 57s} e2 {(Rf2+) -3.97/19 33s} 49. b7 {(Re4+) +1.24/15 38s}
e1=N# {-327.66/3 0s} 0-1[/pgn]

[MikeB]

CCLR flashback to 2006:

so what would you play here....

One thing is for sure, you don't need a computer to spot the under-promotion and mate on the move.

No you don't! was actually looking for a game ending under promotion mate and this was the first one I came across. Also, this game TC was 40/40 and based on Aristarch's evaluation, it was not factoring in the under promotion on its calculation.

[lkaufman]

Back around 1990, when I was testing dedicated chess computers for Computer Chess Reports, I witnessed the rarest thing in chess; a game where the only correct move was to underpromote to a bishop! The test hung up because the other side didn't recognize bishop underpromotion! I imagine that this occurs only once in a million games or so (does anyone know the true odds?) so it was quite a longshot that I would ever witness it.

[Ajedrecista]

Hello:

Back around 1990, when I was testing dedicated chess computers for Computer Chess Reports, I witnessed the rarest thing in chess; a game where the only correct move was to underpromote to a bishop! The test hung up because the other side didn't recognize bishop underpromotion! I imagine that this occurs only once in a million games or so (does anyone know the true odds?) so it was quite a longshot that I would ever witness it.

I remember that some years ago I read on Rybka Forum such a position (surely not the one from 1990). It was about that IPPOLIT could solve it while Rybka not... if I am right. Well, I searched site:rybkaforum.net "bishop underpromotion" in Google and I reach a Rybka Forum post from July, 2009 (before the public release of IPPOLIT) but I think the position is the same:

http://rybkaforum.net/cgi-bin/rybkaforu ... #pid171787

[d]q6N/1p5P/1p6/1P4kp/8/4p2P/4P2K/8 w - - 0 1

It looks like 2.- h8=B+ (if 1.- ..., Kf6 is played) is the key move.

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

No you don't! was actually looking for a game ending under promotion mate and this was the first one I came across. Also, this game TC was 40/40 and based on Aristarch's evaluation, it was not factoring in the under promotion on its calculation.

I did a sort of study almost two years ago:


Some statistics about promotions and underpromotions.

My tool was not perfect (it will never be perfect because it has the same status than those far days) but it gave some ideas. Regarding underpromotions finishing in checkmate, I found some games in huge databases like the excellent CCRL. The most probable case is that a normal promotion to queen also checkmates, but there could be probably a few games where the underpromotion is really needed to checkmate in that move, like in your example.

Using cmd, there are some commands to find certain strings like findstr. I recommend you to download big PGNs from CCRL and CEGT and search the following strings:

Code: Select all

=R#
=B#
=N#

I do not remember if cmd tells the lines where the strings are found. If that, you can isolate the games. Good hunting!

Regards from Spain.

Ajedrecista.

[zullil]

Hello:

http://rybkaforum.net/cgi-bin/rybkaforu ... #pid171787

[d]q6N/1p5P/1p6/1P4kp/8/4p2P/4P2K/8 w - - 0 1

It looks like 2.- h8=B+ (if 1.- ..., Kf6 is played) is the key move.

You mean if Kh4 is played. The underpromotion to a bishop is in this position:
[d]q7/1p3N1P/1p6/1P5p/7k/4p2P/4P2K/8 w - - 2 2

[zullil]

[d]q7/1p3N1P/1p6/1P5p/7k/4p2P/4P2K/8 w - - 2 2

Latest Stockfish finds mate-in-26 starting with the underpromotion:

Code: Select all

info depth 59 seldepth 82 multipv 1 score mate 26 nodes 48053601882 nps 45758057 hashfull 853 tbhits 0 time 1050167 pv h7h8b a8b8 h8e5 b8c7 f7d6 h4g5 d6e4 g5h4 e5g3 c7g3 e4g3 h4g5 g3h5 g5h5 h2g3 h5g6 g3f3 g6f6 f3e3 f6e5 e3d3 e5d5 h3h4 d5c5 h4h5 c5b5 h5h6 b5c5 h6h7 b6b5 h7h8q b5b4 h8d4 c5c6 d3c4 b4b3 d4f6 c6c7 c4b3 c7c8 f6g7 c8b8 b3b4 b8a8 b4c5 a8a7 c5b5 a7b8 b5b6 b8a8 g7b7