7-men pawnless ending + underpromotions

[Tuhma]

I have few questions regarding tablebases and endgames.

1. How ofter OTB happens 7-men pawnless ending. Like how many such games are in megabase 2008? Any idea? Are these just strage curiority or does it happen?
Which one is most usual?

2. How many underpromotion wins / draws are found using tablebases? I mean that how many positions are won because and only because of underpromotion
in krpkr, krrkrp and krpkrp? Any idea? Does anyone have any statictics? Do these tablebase generators produce any statictics regarding this?

Curious,

Tuhma

[Kirill Kryukov]

I have few questions regarding tablebases and endgames.

1. How ofter OTB happens 7-men pawnless ending. Like how many such games are in megabase 2008? Any idea? Are these just strage curiority or does it happen?
Which one is most usual?

2. How many underpromotion wins / draws are found using tablebases? I mean that how many positions are won because and only because of underpromotion
in krpkr, krrkrp and krpkrp? Any idea? Does anyone have any statictics? Do these tablebase generators produce any statictics regarding this?

Curious,

Tuhma

If you have the database of games in question in PGN format, then there are some options available to you to obtain these numbers. Here is what I would try:

PGN Scanner by David J. Barnes can extract games with certain material balance.

Chess Query Language by Gady Costeff and Lewis Stiller allows to perform searches with complex criteria, like you can search for games won by certain underpromotion.

If anyone knows other options, please post.

[Tuhma]

from chessagmes.com (endgame explorer):

KRNPKRB 85 games:
http://www.chessgames.com/perl/chessend ... RB&result=*

KRNNKRB 1 game:
http://www.chessgames.com/perl/chessend ... RB&result=*

KRBNKRB 2 games:
http://www.chessgames.com/perl/chessend ... RB&result=*

KRRNKRB 1 game:
http://www.chessgames.com/perl/chessend ... RB&result=*

KQRNKRB 0(?) game

Then three that happen quite often

KRPPKRP 6,249 games

KBPPKBP 717 games

KNPPKBP 687 games

and few more rarity games.

KRRPKRR 54 games

KRRBKRR 1 game

KRRNKRR 1 game

Quick conclusion is that less than 5% of 7 piece games are pawnless.

If someone can provide more accurate information I would be extremely thankful.

Also does anyone know any 8-piece pawnless game (or even more. What is all time record?)?

Regards,

Tuhma

[h.g.muller]

I am not sure how you arrived at that "quick conclusion". You mention only 6 pawnless 7-men games, and there are more than 6,000 KRPPKRP games. That is somthing like 0.1%

My impression is that pawnless 7-men are completely unimportant. This is why I am so interested in generating EGTBs by P-slice, and then only generating the P-slices you need based on the Pawns that you have left in the ending. That should allow you to do rook endings (KR...KR...) with 4-6 additional Pawns, which would be immensely more useful than all pawnless 7-men combined.

[Tuhma]

Conservative upper boun

I don't know exact number, but I would like to know.

Here are three interesting games. A lot of pieces.

[Event "Gausdal Classics op"]
[Site "Gausdal"]
[Date "2007.04.26"]
[Round "9"]
[White "Greet, Andrew"]
[Black "Lie, Espen"]
[Result "1/2-1/2"]
[BlackElo "2335"]
[WhiteElo "2428"]
[TimeControl "40/3600:40/3600:40/3600"]
[Termination "normal"]
[PlyCount "199"]
[WhiteType "human"]
[BlackType "human"]

1. e4 Nf6 2. e5 Nd5 3. d4 d6 4. Nf3 dxe5 5. Nxe5 g6 6. g3 Bg7 7. Bg2 O-O 8.
O-O c6 9. Re1 Be6 10. Nd2 Nd7 11. Nef3 Nc7 12. Ne4 f6 13. b3 Re8 14. Bb2
Bf7 15. c4 a5 16. a4 Na6 17. Qd2 Qc7 18. Rad1 Rad8 19. Bc3 b6 20. Qb2 Nb4
21. h4 h6 22. Re3 Nf8 23. Rde1 b5 24. axb5 cxb5 25. Nfd2 bxc4 26. bxc4 Rb8
27. Nc5 Nd3 28. Qxb8 Qxb8 29. Nxd3 Qc7 30. Ra1 h5 31. Bxa5 Qd7 32. Bc3 Bh6
33. f4 Ne6 34. d5 Ng7 35. Kh2 g5 36. hxg5 fxg5 37. Ne5 Qc7 38. Nxf7 Kxf7
39. fxg5 Bxg5 40. Rf3 Kg8 41. Ne4 Bh6 42. Ra6 Kh7 43. Rf7 Qxc4 44. Rc6 Qd3
45. d6 h4 46. dxe7 hxg3 47. Nxg3 Kg8 48. Rf3 Qh7 49. Bh3 Qc2 50. Kh1 Rxe7
51. Bf1 Re3 52. Bg2 Qd1 53. Rf1 Qd7 54. Rxh6 Rxg3 55. Be1 Rxg2 56. Kxg2 Qd5
57. Kh2 Qa2 58. Rf2 Qa1 59. Bd2 Qe5 60. Bf4 Qe4 61. Rh3 Nf5 62. Ra3 Qd4 63.
Raf3 Qe4 64. Bb8 Qh4 65. Kg1 Qg4 66. Kh1 Qe4 67. Kg1 Qg4 68. Bg3 Kh7 69.
Rxf5 Qxg3 70. Kh1 Qe3 71. Rf7 Kg6 72. R7f6 Kg7 73. R6f3 Qh6 74. Kg1 Qc1 75.
Rf1 Qg5 76. Kh2 Qh6 77. Kg1 Qg5 78. Kh2 Qh6 79. Kg2 Qd2 80. R1f2 Qd5 81.
Re2 Kg6 82. Rf2 Kg7 83. Kh2 Qe5 84. Rg3 Kh7 85. Kh3 Qh5 86. Kg2 Qd5 87. Kg1
Qd1 88. Rf1 Qd4 89. Kh2 Qd2 90. Rg2 Qh6 91. Kg1 Qe3 92. Kh1 Qe4 93. Rf2 Qe1
94. Kh2 Qe5 95. Rg3 Kh6 96. Rg2 Kh7 97. Kh1 Qe1 98. Rg1 Qe4 99. Kh2 Qe2
100. R1g2 1/2-1/2

[Event "Brno op"]
[Site "Brno"]
[Date "2005.07.08"]
[Round "7"]
[White "Mudrak, Josef"]
[Black "Krcal, Michal"]
[Result "1-0"]
[BlackElo "2013"]
[WhiteElo "2318"]
[TimeControl "40/3600:40/3600:40/3600"]
[Termination "normal"]
[PlyCount "107"]
[WhiteType "human"]
[BlackType "human"]

1. d4 Nf6 2. Nf3 g6 3. g3 Bg7 4. Bg2 d5 5. O-O O-O 6. c4 dxc4 7. Nc3 c6 8.
h3 Na6 9. e4 Nc7 10. Be3 Nfe8 11. Qe2 Nd6 12. Rad1 h6 13. Ne5 Be6 14. f4
Qe8 15. g4 f5 16. d5 cxd5 17. exd5 Bd7 18. Rde1 Ncb5 19. Bd2 Nd4 20. Qd1
Rd8 21. a4 fxg4 22. hxg4 h5 23. Be3 Nb3 24. Nxd7 Rxd7 25. Bh3 hxg4 26. Bxg4
Nf5 27. Bxa7 b5 28. Bf2 b4 29. Nb5 Qf7 30. Bf3 Nd6 31. Bg4 Nf5 32. Bf3 Nd6
33. Nxd6 Rxd6 34. Bg3 Qf5 35. Rxe7 Qh3 36. Bh2 Bd4 37. Kh1 Nd2 38. Bg2 Qd3
39. Rfe1 c3 40. bxc3 bxc3 41. Rc7 Qf5 42. Qe2 g5 43. fxg5 Rg6 44. d6 Qxg5
45. d7 Rh6 46. Rc8 Rxh2 47. Kxh2 Qf4 48. Kh1 Qh4 49. Bh3 Qxh3 50. Qh2 Qxd7
51. Qg2 Bg7 52. Rxc3 Qxa4 53. Qd5 Rf7 54. Rc8 1-0

[Event "Gausdal Classics op"]
[Site "Gausdal"]
[Date "2007.04.26"]
[Round "9"]
[White "Greet, Andrew"]
[Black "Lie, Espen"]
[Result "1/2-1/2"]
[BlackElo "2335"]
[WhiteElo "2428"]
[TimeControl "40/3600:40/3600:40/3600"]
[Termination "normal"]
[PlyCount "199"]
[WhiteType "human"]
[BlackType "human"]

1. e4 Nf6 2. e5 Nd5 3. d4 d6 4. Nf3 dxe5 5. Nxe5 g6 6. g3 Bg7 7. Bg2 O-O 8.
O-O c6 9. Re1 Be6 10. Nd2 Nd7 11. Nef3 Nc7 12. Ne4 f6 13. b3 Re8 14. Bb2
Bf7 15. c4 a5 16. a4 Na6 17. Qd2 Qc7 18. Rad1 Rad8 19. Bc3 b6 20. Qb2 Nb4
21. h4 h6 22. Re3 Nf8 23. Rde1 b5 24. axb5 cxb5 25. Nfd2 bxc4 26. bxc4 Rb8
27. Nc5 Nd3 28. Qxb8 Qxb8 29. Nxd3 Qc7 30. Ra1 h5 31. Bxa5 Qd7 32. Bc3 Bh6
33. f4 Ne6 34. d5 Ng7 35. Kh2 g5 36. hxg5 fxg5 37. Ne5 Qc7 38. Nxf7 Kxf7
39. fxg5 Bxg5 40. Rf3 Kg8 41. Ne4 Bh6 42. Ra6 Kh7 43. Rf7 Qxc4 44. Rc6 Qd3
45. d6 h4 46. dxe7 hxg3 47. Nxg3 Kg8 48. Rf3 Qh7 49. Bh3 Qc2 50. Kh1 Rxe7
51. Bf1 Re3 52. Bg2 Qd1 53. Rf1 Qd7 54. Rxh6 Rxg3 55. Be1 Rxg2 56. Kxg2 Qd5
57. Kh2 Qa2 58. Rf2 Qa1 59. Bd2 Qe5 60. Bf4 Qe4 61. Rh3 Nf5 62. Ra3 Qd4 63.
Raf3 Qe4 64. Bb8 Qh4 65. Kg1 Qg4 66. Kh1 Qe4 67. Kg1 Qg4 68. Bg3 Kh7 69.
Rxf5 Qxg3 70. Kh1 Qe3 71. Rf7 Kg6 72. R7f6 Kg7 73. R6f3 Qh6 74. Kg1 Qc1 75.
Rf1 Qg5 76. Kh2 Qh6 77. Kg1 Qg5 78. Kh2 Qh6 79. Kg2 Qd2 80. R1f2 Qd5 81.
Re2 Kg6 82. Rf2 Kg7 83. Kh2 Qe5 84. Rg3 Kh7 85. Kh3 Qh5 86. Kg2 Qd5 87. Kg1
Qd1 88. Rf1 Qd4 89. Kh2 Qd2 90. Rg2 Qh6 91. Kg1 Qe3 92. Kh1 Qe4 93. Rf2 Qe1
94. Kh2 Qe5 95. Rg3 Kh6 96. Rg2 Kh7 97. Kh1 Qe1 98. Rg1 Qe4 99. Kh2 Qe2
100. R1g2 1/2-1/2

[guyhaw]

I have these figures, dating from some time ago (and thanks to whoever provided them to me). The %s are probably still about right.

Games featuring endgames with 'n or less' men on the board (including the Ks):

2 men 8705 0.25%
3 men 43588 1.27%
4 men 98594 2.88%
5 men 177485 5.19%
6 men 272011 7.95%
7 men 381203 11.15%
8 men 498988 14.59%
9 men 626286 18.31%
10 men 770177 22.52%
11 men 923950 27.01%
12 men 1103255 32.26%
13 men 1286984 37.63%
14 men 1500913 43.88%
15 men 1700264 49.71%
16 men 1923726 56.25%
17 men 2112539 61.77%
18 men 2316490 67.73%
19 men 2472478 72.29%
20 men 2642271 77.26%
21 men 2760678 80.72%
22 men 2896807 84.70%
23 men 2980506 87.15%
24 men 3088352 90.30%
25 men 3141869 91.86%
26 men 3227422 94.36%
27 men 3258484 95.27%
28 men 3325061 97.22%
29 men 3340993 97.69%
30 men 3389501 99.10%
31 men 3395513 99.28%
32 men 3420157 100.00%

Games featuring this combination of men:

1-1 8705 0.25%
2-1 43588 1.27%
2-2 60843 1.78%
3-1 37751 1.10%
3-2 156665 4.58%
4-1 20820 0.61%
3-3 139274 4.07%
4-2 121394 3.55%
5-1 11343 0.33%
4-3 315800 9.23%
5-2 59712 1.75%
6-1 5691 0.17%
4-4 255813 7.48%
5-3 214519 6.27%
6-2 26031 0.76%
7-1 2625 0.08%
5-4 516557 15.10%
6-3 97763 2.86%
7-2 10919 0.32%
8-1 1047 0.03%
5-5 404684 11.83%
6-4 322641 9.43%
7-3 38137 1.12%
8-2 4326 0.13%
9-1 389 0.01%
6-5 772498 22.59%
7-4 135691 3.97%
8-3 14104 0.41%
9-2 1525 0.04%
10-1 132 0.00%
6-6 605601 17.71%
7-5 445002 13.01%
8-4 47277 1.38%
9-3 4807 0.14%
10-2 516 0.02%
11-1 52 0.00%
7-6 1098563 32.12%
8-5 171585 5.02%
9-4 15090 0.44%
10-3 1532 0.04%
11-2 198 0.01%
12-1 16 0.00%
7-7 869675 25.43%
8-6 573665 16.77%
9-5 52455 1.53%
10-4 4485 0.13%
11-3 559 0.02%
12-2 64 0.00%
13-1 10 0.00%
8-7 1488482 43.52%
9-6 195709 5.72%
10-5 14380 0.42%
11-4 1482 0.04%
12-3 190 0.01%
13-2 21 0.00%
8-8 1189129 34.77%
9-7 678717 19.84%
10-6 51325 1.50%
11-5 4014 0.12%
12-4 470 0.01%
13-3 61 0.00%
14-2 10 0.00%
9-8 1898882 55.52%
10-7 200187 5.85%
11-6 12144 0.36%
12-5 1160 0.03%
13-4 143 0.00%
14-3 18 0.00%
15-2 3 0.00%
16-1 2 0.00%
9-9 1533135 44.83%
10-8 735640 21.51%
11-7 44266 1.29%
12-6 3084 0.09%
13-5 313 0.01%
14-4 45 0.00%
15-3 4 0.00%
16-2 3 0.00%
10-9 2281365 66.70%
11-8 181068 5.29%
12-7 9191 0.27%
13-6 763 0.02%
14-5 78 0.00%
15-4 10 0.00%
16-3 3 0.00%
10-10 1879537 54.95%
11-9 727137 21.26%
12-8 33363 0.98%
13-7 2014 0.06%
14-6 190 0.01%
15-5 26 0.00%
16-4 4 0.00%
11-10 2610324 76.32%
12-9 143993 4.21%
13-8 5877 0.17%
14-7 433 0.01%
15-6 44 0.00%
16-5 7 0.00%
11-11 2219764 64.90%
12-10 654514 19.14%
13-9 21355 0.62%
14-8 1078 0.03%
15-7 86 0.00%
16-6 10 0.00%
12-11 2877703 84.14%
13-10 99467 2.91%
14-9 3112 0.09%
15-8 211 0.01%
16-7 13 0.00%
12-12 2545706 74.43%
13-11 530035 15.50%
14-10 12100 0.35%
15-9 482 0.01%
16-8 29 0.00%
13-12 3082298 90.12%
14-11 58202 1.70%
15-10 1307 0.04%
16-9 62 0.00%
13-13 2840557 83.05%
14-12 381698 11.16%
15-11 5023 0.15%
16-10 144 0.00%
14-13 3231172 94.47%
15-12 26979 0.79%
16-11 333 0.01%
14-14 3083256 90.15%
15-13 240586 7.03%
16-12 1219 0.04%
15-14 3332036 97.42%
16-13 8957 0.26%
15-15 3232999 94.53%
16-14 156502 4.58%
16-15 3395513 99.28%
16-16 3420157 100.00%

So, 7-man or less is 11.15%, of which 9.23% is 4-3.

g

[h.g.muller]

I think the question was which fraction of the 7-men where Pawnless. Not which fraction of the total were 7-men...