Under promotion of a pinned pawn to bishop

[OliverBr]

Hello together,
chess puzzle lovers will love this: A position from a real game where an under-promotion to bishop happens. And even better, a pinned pawn under-promoted.
If you ask me, this is a 1 in a million situation:

[d]4b3/1k1P4/1P6/1K3p2/5N2/8/8/8 w - - 1 67 bm dxe8=b

(Mate in 7 with underpromotion to bishop)
And here the complete game between Fruit 2.1 and OliThink 5.7.0:


[pgn]
[Event "?"]
[Site "?"]
[Date "2020.09.03"]
[Round "4256"]
[White "Fruit 2.1"]
[Black "OliThink 5.7.0"]
[Result "1-0"]

1. c3 e5 2. c4 Nc6 3. Qc2 Nf6 4. Nf3 e4 5. Ng5 d5 6. cxd5 Qxd5 7. h4 Nb4 8. Qd1
Qf5 9. d3 Bc5 10. Be3 exd3 11. exd3 Bxe3 12. fxe3 Ng4 13. Qd2 Qc5 14. Nc3 Qxe3+
15. Qxe3+ Nxe3 16. Kd2 f6 17. Nf3 Nxf1+ 18. Rhxf1 O-O 19. a3 Nc6 20. Nb5 Bf5
21. Nfd4 Nxd4 22. Nxd4 Bg4 23. Rae1 Rfe8 24. Nb5 Rxe1 25. Rxe1 c6 26. Nd6 b6
27. Rc1 c5 28. b4 cxb4 29. axb4 Rd8 30. Ne4 Be6 31. Rc7 Bd5 32. Ng3 g6 33. Ne2
Bxg2 34. Rxa7 Be4 35. d4 f5 36. Rc7 Bg2 37. Kc3 b5 38. Nf4 Bf3 39. Ne6 Re8
40. Ng5 Bd5 41. Nxh7 Re3+ 42. Kd2 Re6 43. Ng5 Rd6 44. Ke3 Rd8 45. Rc5 Kg7
46. Rxb5 Kh6 47. Nh3 Bc4 48. Rc5 Re8+ 49. Kf2 Re2+ 50. Kf3 Rc2 51. Nf4 g5
52. hxg5+ Kxg5 53. Nh3+ Kf6 54. Kf4 Bd3 55. Ke3 Bc4 56. Nf4 Bb3 57. Rxc2 Bxc2
58. b5 Ke7 59. d5 Kd6 60. b6 Bb3 61. Kd4 Ba2 62. Kc3 Kd7 63. Kb4 Kc8 64. Kb5 Kb7
65. d6 Bf7 66. d7 Be8 67. dxe8=B 1-0
[/pgn]

For information: OliThink 5.7.0 has a little bug, where it can't do underpromtions of pinned pawns. Promotion of pinned-pawns are already very rare, now who would ever think there was an underpromotion of a pinned pawn. An not artificially constructed, it's real.

It could only be detected because of that little bug in OliThink 5.7.0, after Fruit's move, it stalled. In OliThink 5.7.1 this bug is fixed.

[MOBMAT]

Hello together,
chess puzzle lovers will love this: A position from a real game where an under-promotion to bishop happens. And even better, a pinned pawn under-promoted.
If you ask me, this is a 1 in a million situation:

[d]4b3/1k1P4/1P6/1K3p2/5N2/8/8/8 w - - 1 67

And here the complete game between Fruit 2.1 and OliThink 5.7.0:


[pgn]
[Event "?"]
[Site "?"]
[Date "2020.09.03"]
[Round "4256"]
[White "Fruit 2.1"]
[Black "OliThink 5.7.0"]
[Result "1-0"]

1. c3 e5 2. c4 Nc6 3. Qc2 Nf6 4. Nf3 e4 5. Ng5 d5 6. cxd5 Qxd5 7. h4 Nb4 8. Qd1
Qf5 9. d3 Bc5 10. Be3 exd3 11. exd3 Bxe3 12. fxe3 Ng4 13. Qd2 Qc5 14. Nc3 Qxe3+
15. Qxe3+ Nxe3 16. Kd2 f6 17. Nf3 Nxf1+ 18. Rhxf1 O-O 19. a3 Nc6 20. Nb5 Bf5
21. Nfd4 Nxd4 22. Nxd4 Bg4 23. Rae1 Rfe8 24. Nb5 Rxe1 25. Rxe1 c6 26. Nd6 b6
27. Rc1 c5 28. b4 cxb4 29. axb4 Rd8 30. Ne4 Be6 31. Rc7 Bd5 32. Ng3 g6 33. Ne2
Bxg2 34. Rxa7 Be4 35. d4 f5 36. Rc7 Bg2 37. Kc3 b5 38. Nf4 Bf3 39. Ne6 Re8
40. Ng5 Bd5 41. Nxh7 Re3+ 42. Kd2 Re6 43. Ng5 Rd6 44. Ke3 Rd8 45. Rc5 Kg7
46. Rxb5 Kh6 47. Nh3 Bc4 48. Rc5 Re8+ 49. Kf2 Re2+ 50. Kf3 Rc2 51. Nf4 g5
52. hxg5+ Kxg5 53. Nh3+ Kf6 54. Kf4 Bd3 55. Ke3 Bc4 56. Nf4 Bb3 57. Rxc2 Bxc2
58. b5 Ke7 59. d5 Kd6 60. b6 Bb3 61. Kd4 Ba2 62. Kc3 Kd7 63. Kb4 Kc8 64. Kb5 Kb7
65. d6 Bf7 66. d7 Be8 67. dxe8=B 1-0
[/pgn]

For information: OliThink 5.7.0 has a little bug, where it can't do underpromtions of pinned pawns. Promotion of pinned-pawns are already very rare, now who would ever think there was an underpromotion of a pinned pawn. An not artificially constructed, it's real.

It could only be detected because of that little bug in OliThink 5.7.0, after Fruit's move, it stalled. In OliThink 5.7.1 this bug is fixed.

One in a million, that is an interesting way to put it. If you are considering moves made in every game every played, then that might be a low figure. If you are basing it on the number of possible moves that can be made from any square to any other square, well, that number is a lot lower. Not sure of the exact value, but I do recall running into a U16 overflow when I was building a database of historic games. I indexed each possible unique move as they occurred in the games that were added, and eventually the number exceeded 64,384 which required me to switch to a 32-bit index. I think the total number of moves ended up being near 66,000 or so. That was for 6 million + games.

[Dann Corbit]

There are plenty of games on Lichess if someone wants to do statistical analysis.
Only problem is that most of the games are very low quality.
It is like fics games.

[chrisw]

Hello together,
chess puzzle lovers will love this: A position from a real game where an under-promotion to bishop happens. And even better, a pinned pawn under-promoted.
If you ask me, this is a 1 in a million situation:

[d]4b3/1k1P4/1P6/1K3p2/5N2/8/8/8 w - - 1 67 bm dxe8=b

(Mate in 7 with underpromotion to bishop)
And here the complete game between Fruit 2.1 and OliThink 5.7.0:


[pgn]
[Event "?"]
[Site "?"]
[Date "2020.09.03"]
[Round "4256"]
[White "Fruit 2.1"]
[Black "OliThink 5.7.0"]
[Result "1-0"]

1. c3 e5 2. c4 Nc6 3. Qc2 Nf6 4. Nf3 e4 5. Ng5 d5 6. cxd5 Qxd5 7. h4 Nb4 8. Qd1
Qf5 9. d3 Bc5 10. Be3 exd3 11. exd3 Bxe3 12. fxe3 Ng4 13. Qd2 Qc5 14. Nc3 Qxe3+
15. Qxe3+ Nxe3 16. Kd2 f6 17. Nf3 Nxf1+ 18. Rhxf1 O-O 19. a3 Nc6 20. Nb5 Bf5
21. Nfd4 Nxd4 22. Nxd4 Bg4 23. Rae1 Rfe8 24. Nb5 Rxe1 25. Rxe1 c6 26. Nd6 b6
27. Rc1 c5 28. b4 cxb4 29. axb4 Rd8 30. Ne4 Be6 31. Rc7 Bd5 32. Ng3 g6 33. Ne2
Bxg2 34. Rxa7 Be4 35. d4 f5 36. Rc7 Bg2 37. Kc3 b5 38. Nf4 Bf3 39. Ne6 Re8
40. Ng5 Bd5 41. Nxh7 Re3+ 42. Kd2 Re6 43. Ng5 Rd6 44. Ke3 Rd8 45. Rc5 Kg7
46. Rxb5 Kh6 47. Nh3 Bc4 48. Rc5 Re8+ 49. Kf2 Re2+ 50. Kf3 Rc2 51. Nf4 g5
52. hxg5+ Kxg5 53. Nh3+ Kf6 54. Kf4 Bd3 55. Ke3 Bc4 56. Nf4 Bb3 57. Rxc2 Bxc2
58. b5 Ke7 59. d5 Kd6 60. b6 Bb3 61. Kd4 Ba2 62. Kc3 Kd7 63. Kb4 Kc8 64. Kb5 Kb7
65. d6 Bf7 66. d7 Be8 67. dxe8=B 1-0
[/pgn]

For information: OliThink 5.7.0 has a little bug, where it can't do underpromtions of pinned pawns. Promotion of pinned-pawns are already very rare, now who would ever think there was an underpromotion of a pinned pawn. An not artificially constructed, it's real.

It could only be detected because of that little bug in OliThink 5.7.0, after Fruit's move, it stalled. In OliThink 5.7.1 this bug is fixed.

I recently add a movegen test, actually only for some special cases, where: (already know pinned piece(s) and pinners()), make a mask composed of bits inbetween(king, pinner) OR-ed with Pinner, AND that with the pinned piece movemask.

For safety, if there’s more than one Pinner, only use the mask IF pinned AND mask is true.

[OliverBr]

I recently add a movegen test, actually only for some special cases, where: (already know pinned piece(s) and pinners()), make a mask composed of bits inbetween(king, pinner) OR-ed with Pinner, AND that with the pinned piece movemask.

For safety, if there’s more than one Pinner, only use the mask IF pinned AND mask is true.

"more than one Pinner". Terrific!
Is it only possible with R+Q/R or B+Q in a row? Or am I missing something?

[chrisw]

I recently add a movegen test, actually only for some special cases, where: (already know pinned piece(s) and pinners()), make a mask composed of bits inbetween(king, pinner) OR-ed with Pinner, AND that with the pinned piece movemask.

For safety, if there’s more than one Pinner, only use the mask IF pinned AND mask is true.

"more than one Pinner". Terrific!
Is it only possible with R+Q/R or B+Q in a row? Or am I missing something?

There are situations where more than one piece is pinned, so how you store pinned and pinners is important. The SF paradigm is that all pinners are in one bitmask, and all pinned are in another. (I guess #pinned = #pinners, but that’s not important here). If there’s multiple pinned pieces then SF paradigm needs to disentangle what is pinning what (I’m not sure that they do actually, but that’s another story too). By using inbetween mask you can solve this problem as well as using it for the movemask.

[Ajedrecista]

Hello Oliver:

Hello together,
chess puzzle lovers will love this: A position from a real game where an under-promotion to bishop happens. And even better, a pinned pawn under-promoted.
If you ask me, this is a 1 in a million situation:

[d]4b3/1k1P4/1P6/1K3p2/5N2/8/8/8 w - - 1 67 bm dxe8=b

(Mate in 7 with underpromotion to bishop)
And here the complete game between Fruit 2.1 and OliThink 5.7.0:


[pgn]
[Event "?"]
[Site "?"]
[Date "2020.09.03"]
[Round "4256"]
[White "Fruit 2.1"]
[Black "OliThink 5.7.0"]
[Result "1-0"]

1. c3 e5 2. c4 Nc6 3. Qc2 Nf6 4. Nf3 e4 5. Ng5 d5 6. cxd5 Qxd5 7. h4 Nb4 8. Qd1
Qf5 9. d3 Bc5 10. Be3 exd3 11. exd3 Bxe3 12. fxe3 Ng4 13. Qd2 Qc5 14. Nc3 Qxe3+
15. Qxe3+ Nxe3 16. Kd2 f6 17. Nf3 Nxf1+ 18. Rhxf1 O-O 19. a3 Nc6 20. Nb5 Bf5
21. Nfd4 Nxd4 22. Nxd4 Bg4 23. Rae1 Rfe8 24. Nb5 Rxe1 25. Rxe1 c6 26. Nd6 b6
27. Rc1 c5 28. b4 cxb4 29. axb4 Rd8 30. Ne4 Be6 31. Rc7 Bd5 32. Ng3 g6 33. Ne2
Bxg2 34. Rxa7 Be4 35. d4 f5 36. Rc7 Bg2 37. Kc3 b5 38. Nf4 Bf3 39. Ne6 Re8
40. Ng5 Bd5 41. Nxh7 Re3+ 42. Kd2 Re6 43. Ng5 Rd6 44. Ke3 Rd8 45. Rc5 Kg7
46. Rxb5 Kh6 47. Nh3 Bc4 48. Rc5 Re8+ 49. Kf2 Re2+ 50. Kf3 Rc2 51. Nf4 g5
52. hxg5+ Kxg5 53. Nh3+ Kf6 54. Kf4 Bd3 55. Ke3 Bc4 56. Nf4 Bb3 57. Rxc2 Bxc2
58. b5 Ke7 59. d5 Kd6 60. b6 Bb3 61. Kd4 Ba2 62. Kc3 Kd7 63. Kb4 Kc8 64. Kb5 Kb7
65. d6 Bf7 66. d7 Be8 67. dxe8=B 1-0
[/pgn]

For information: OliThink 5.7.0 has a little bug, where it can't do underpromtions of pinned pawns. Promotion of pinned-pawns are already very rare, now who would ever think there was an underpromotion of a pinned pawn. An not artificially constructed, it's real.

It could only be detected because of that little bug in OliThink 5.7.0, after Fruit's move, it stalled. In OliThink 5.7.1 this bug is fixed.

Nice position from a real game! I did a little research about promotions and underpromotions seven years ago:

Some statistics about promotions and underpromotions.

Since I am not a programmer, my tool did not provide exact results but almost. I analyzed CCRL 40/40 database (1,172,820 games) because CCRL 40/4 has more games and the elapsed time would be higher. Anyway, I did small changes on my tool to search the right strings. Here is what I have found after 3342.0 seconds (0:55:42.0) on my old PC:

Code: Select all

CCRL-4040.[1172820].pgn
 
xa1=B:      10
xb1=B:      23
xc1=B:      19
xd1=B:      22
xe1=B:      18
xf1=B:      25
xg1=B:      10
xh1=B:       1
xa8=B:      14
xb8=B:      18
xc8=B:      33
xd8=B:      27
xe8=B:      22
xf8=B:      38
xg8=B:      17
xh8=B:       4
xa1=B+:      0
xb1=B+:      4
xc1=B+:      2
xd1=B+:      3
xe1=B+:      4
xf1=B+:      5
xg1=B+:      3
xh1=B+:      0
xa8=B+:      0
xb8=B+:      2
xc8=B+:      3
xd8=B+:      7
xe8=B+:      7
xf8=B+:      7
xg8=B+:      8
xh8=B+:      1
xa1=B#:      0
xb1=B#:      0
xc1=B#:      0
xd1=B#:      0
xe1=B#:      0
xf1=B#:      0
xg1=B#:      0
xh1=B#:      0
xa8=B#:      0
xb8=B#:      0
xc8=B#:      0
xd8=B#:      0
xe8=B#:      0
xf8=B#:      0
xg8=B#:      0
xh8=B#:      0
 
==============================
 
Nor checks neither checkmates:
 
a1    10
b1    19
c1    17
d1    19
e1    14
f1    20
g1     7
h1     1
a8    14
b8    16
c8    30
d8    20
e8    15
f8    31
g8     9
h8     3

I searched captures that were bishop underpromotions. Since I am not able to detect if the king of the promoting side was pinned, those numbers are meant to be understood as upper bounds. Most of those bishop underpromotions would be in positions where kings were not pinned indeed. Just to put the numbers in context, here are the results of an excellent tool called Joined after circa 30 minutes of run:

Code: Select all

joined -q -v64 CCRL-4040.[1172820].pgn
Scanning file CCRL-4040.[1172820].pgn containing 1307549190 bytes !

[...]

94.8%: Line 28511542, game 1110272, 149444568 moves, 4294022023 pos, max 745, 84
94.8%: Line 28514878, game 1110400, 149462923 moves, 4294563689 pos, max 745, 84
100.0%: Line 30077298, game 1172224, 157496289 moves, 235142570 pos, max 745, 84
100.0%: Line 30080475, game 1172352, 157512519 moves, 235627231 pos, max 745, 84
100.0%: Line 30083605, game 1172480, 157529369 moves, 236121831 pos, max 745, 84
100.0%: Line 30086644, game 1172608, 157544365 moves, 236559292 pos, max 745, 84
100.0%: Line 30089808, game 1172736, 157559958 moves, 237019031 pos, max 745, 84
Read 1172820 games with 157570821 moves, 30091940 lines, 1307549190 bytes !
Got max. 745 moves in game 1092971 before line 28075317 !
Got 237335240 legal moves in 158743641 positons !
Got max. 84 legal moves after move 116 in game 121733 line 3144196 !

Total move statistics:
Pawn moves = 32480351, Knight moves = 21658350, Bishop moves = 24066608
Rook moves = 35378214, Queen moves = 20149886, King moves = 25931391
Check moves = 10300013, Mate moves = 48889, Stalemate moves = 2032
Hit moves = 25093686, En passant moves = 78397, Pawn two moves = 7424753
Short castlings = 1901544, Long castlings = 192435
Promotion to queen = 183772, Promotion to rook = 10159
Promotion to bishop = 2757, Promotion to knight = 5437

Total game statistics:
White won = 404405, Drawn = 469663, Black won = 298752
Unknown result = 0, Illegal result = 0, Conflicting results = 0
White mated = 21399, White stalemated = 993
Black mated = 27490, Black stalemated = 1039

Number of games with different lengths:
 28:   225,  29:   272,  30:   231,  31:   366,  32:   348,  33:   382
 34:   434,  35:   446,  36:   504,  37:   502,  38:   526,  39:   606
 40:   655,  41:   788,  42:   752,  43:   720,  44:   794,  45:   838
 46:   919,  47:   954,  48:  1069,  49:  1109,  50:  1328,  51:  1283
 52:  1525,  53:  1549,  54:  1779,  55:  1739,  56:  1996,  57:  1964
 58:  2239,  59:  2140,  60:  2527,  61:  2412,  62:  2860,  63:  2772
 64:  3011,  65:  2919,  66:  3439,  67:  3237,  68:  3777,  69:  3723
 70:  4070,  71:  4051,  72:  4491,  73:  4387,  74:  4996,  75:  4994
 76:  5351,  77:  5154,  78:  5688,  79:  5649,  80:  6251,  81:  5781
 82:  6786,  83:  6488,  84:  7513,  85:  7751,  86:  8733,  87:  8935
 88: 10459,  89:  8193,  90:  8886,  91:  8489,  92:  9095,  93:  8820
 94:  9695,  95:  9089,  96: 10049,  97:  9650,  98: 10181,  99:  9834
100: 10519, 101: 10196, 102: 10923, 103: 10458, 104: 11192, 105: 10645
106: 11394, 107: 11026, 108: 11563, 109: 11086, 110: 11836, 111: 11080
112: 11799, 113: 11358, 114: 11808, 115: 11185, 116: 11802, 117: 11258
118: 11859, 119: 11306, 120: 11552, 121: 11128, 122: 35614, 123: 12203
124: 12605, 125: 11881, 126: 12160, 127: 11836, 128: 11961, 129: 11423
130: 11539, 131: 11288, 132: 11352, 133: 11007, 134: 10629, 135: 10540
136: 10360, 137: 10126, 138: 10092, 139:  9939, 140:  9611, 141:  9362
142:  9305, 143:  8790, 144: 10624, 145:  8623, 146:  8293, 147:  8015
148:  7810, 149:  7751, 150:  7596, 151:  7373, 152:  7132, 153:  6930
154:  6943, 155:  6457, 156:  6495, 157:  6191, 158:  6198, 159:  5943
160:  9132, 161:  5531, 162:  5489, 163:  5397, 164:  5383, 165:  5627
166:  5553, 167:  5539, 168:  5535, 169:  4734, 170:  4536, 171:  4300
172:  4149, 173:  4046, 174:  3907, 175:  3810, 176:  3707, 177:  3568
178:  3557, 179:  3444, 180:  3238, 181:  3222, 182:  3019, 183:  2964
184:  2835, 185:  2772, 186:  2787, 187:  2755, 188:  2615, 189:  2569
190:  2493, 191:  2478, 192:  2318, 193:  2441, 194:  2289, 195:  2319
196:  2185, 197:  2179, 198:  2094, 199:  2059, 200:  2058, 201:  1846
202:  1899, 203:  1926, 204:  1836, 205:  1777, 206:  1773, 207:  1772
208:  1722, 209:  1661, 210:  1722, 211:  1615, 212:  1619, 213:  1596
214:  1498, 215:  1501, 216:  1435, 217:  1427, 218:  1396, 219:  1399
220:  1357, 221:  1354, 222:  1280, 223:  1332, 224:  1281, 225:  1362
226:  1283, 227:  1304, 228:  1225, 229:  1264, 230:  1159, 231:  1137
232:  1124, 233:  1123, 234:  1114, 235:  1041, 236:  1097, 237:  1026
238:  1020, 239:   986, 240:  1088, 241:   964, 242:   983, 243:   928
244:   929, 245:  1004, 246:   935, 247:   913, 248:   912, 249:   880
250:   880, 251:   836, 252:   813, 253:   778, 254:   752, 255:   772
256:   773, 257:   679, 258:   689, 259:   743, 260:   712, 261:   700
262:   685, 263:   658, 264:   674, 265:   630, 266:   566, 267:   544
268:   578, 269:   578, 270:   548, 271:   505, 272:   565, 273:   558
274:   514, 275:   554, 276:   477, 277:   543, 278:   483, 279:   485
280:   416, 281:   464, 282:   446, 283:   425, 284:   419, 285:   378
286:   411, 287:   381, 288:   424, 289:   417, 290:   390, 291:   374
292:   362, 293:   354, 294:   397, 295:   347, 296:   371, 297:   378
298:   346, 299:   325, 300:   359, 301:   328, 302:   325, 303:   338
304:   317, 305:   305, 306:   324, 307:   306, 308:   303, 309:   300
310:   249, 311:   282, 312:   292, 313:   272, 314:   293, 315:   235
316:   260, 317:   260, 318:   259, 319:   261, 320:   303, 321:   268
322:   218, 323:   222, 324:   233, 325:   235, 326:   248, 327:   236
328:   223, 329:   249, 330:   214, 331:   191, 332:   196, 333:   206
334:   178, 335:   215, 336:   176, 337:   159, 338:   209, 339:   186
340:   190, 341:   170, 342:   174, 343:   172, 344:   157, 345:   173
346:   155, 347:   146, 348:   151, 349:   140, 350:   139, 351:   129
352:   154, 353:   144, 354:   129, 355:   111, 356:   137, 357:   113
358:   119, 359:   122, 360:   896, 361:   132, 362:   102, 363:    88
364:   113, 365:    94, 366:    72, 367:    89, 368:    93, 369:    98
370:    90, 371:    82, 372:    95, 373:    67, 374:    76, 375:    67
376:    80, 377:    82, 378:    66, 379:    67, 380:    81, 381:    76
382:    67, 383:    78, 384:    63, 385:    68, 386:    66, 387:    67
388:    59, 389:    65, 390:    65, 391:    58, 392:    64, 393:    61
394:    65, 395:    48, 396:    67, 397:    60, 398:    61, 399:    55
400:   186, 401:    66, 402:    47, 403:    46, 404:    48, 405:    69
406:    59, 407:    39, 408:    48, 409:    50, 410:    41, 411:    33
412:    37, 413:    31, 414:    44, 415:    52, 416:    40, 417:    42
418:    35, 419:    41, 420:    34, 421:    36, 422:    23, 423:    42
424:    30, 425:    40, 426:    27, 427:    28, 428:    42, 429:    32
430:    29, 431:    32, 432:    29, 433:    25, 434:    35, 435:    22
436:    30, 437:    33, 438:    27, 439:    35, 440:    22, 441:    29
442:    26, 443:    25, 444:    31, 445:    27, 446:    19, 447:    27
448:    19, 449:    23, 450:    25, 451:    21, 452:    24, 453:    20
454:    21, 455:    17, 456:    20, 457:    22, 458:    22, 459:    14
460:    14, 461:     9, 462:    17, 463:    14, 464:    11, 465:    22
466:    12, 467:    17, 468:    15, 469:    15, 470:    23, 471:    13
472:    12, 473:    14, 474:    13, 475:    14, 476:    16, 477:    18
478:    13, 479:    15, 480:    11, 481:    11, 482:    11, 483:    16
484:    14, 485:    16, 486:     9, 487:    15, 488:     8, 489:    11
490:    12, 491:    14, 492:     8, 493:    10, 494:    13, 495:    11
496:     9, 497:     6, 498:     9, 499:    13, 500:   147, 501:     4
502:     5, 503:     8, 504:     5, 505:     6, 506:     6, 507:     5
508:     4, 509:     5, 510:    13, 511:     4, 512:     2, 513:     4
514:    10, 515:     3, 516:     2, 517:    10, 518:     7, 519:     9
520:     7, 521:     4, 522:     5, 523:     4, 524:     8, 525:     2
526:     4, 527:     5, 528:     5, 529:     4, 530:     4, 531:     3
532:     2, 534:     3, 535:     2, 536:     3, 537:     4, 538:     3
539:     4, 540:     2, 541:     4, 542:     2, 543:     3, 544:     3
546:     2, 548:     3, 549:     3, 551:     4, 552:     1, 553:     2
554:     5, 555:     2, 556:     3, 557:     2, 558:     1, 559:     2
560:     1, 563:     2, 564:     3, 565:     5, 566:     3, 567:     1
568:     2, 570:     2, 573:     2, 574:     2, 575:     2, 576:     1
577:     3, 579:     1, 580:    11, 581:     1, 582:     1, 583:     2
585:     2, 588:     1, 589:     3, 592:     3, 593:     1, 598:     1
600:    18, 614:     1, 616:     1, 624:     1, 631:     1, 641:     1
657:     1, 691:     1, 702:     1, 718:     1, 745:     1

There were 2757 underpromotions to bishop in 157,570,821 moves (plies). Only 301 of them (more less) where after captures according to my tool. To avoid stalemates, those underpromotions must be without giving checks or checkmates, hence I searched them also and substracted from 301, finally obtaining 245 at most that ought to fulfill expectations. This means 245/(157,570,821) ~ 1/(643,146.2); further analysis of these 245 positions would show unpinned kings in most of the cases or even pieces that are going to be captured anyway (so maybe queening was possible without stalemating), so 1 in a million feels way short to me. More like 1 in 10 million or surely rarer as my wild guess.

Regards from Spain.

Ajedrecista.

[OliverBr]

Hello Ajedrecista,

Nice position from a real game! I did a little research about promotions and underpromotions seven years ago:

Some statistics about promotions and underpromotions.

Since I am not a programmer, my tool did not provide exact results
...
There were 2757 underpromotions to bishop in 157,570,821 moves (plies). Only 301 of them (more less) where after captures according to my tool. To avoid stalemates, those underpromotions must be without giving checks or checkmates, hence I searched them also and substracted from 301, finally obtaining 245 at most that ought to fulfill expectations. This means 245/(157,570,821) ~ 1/(643,146.2); further analysis of these 245 positions would show unpinned kings in most of the cases or even pieces that are going to be captured anyway (so maybe queening was possible without stalemating), so 1 in a million feels way short to me. More like 1 in 10 million or surely rarer as my wild guess.

Regards from Spain.

Ajedrecista.

I am impressed!
Thank you very much for your analysis. I knew that such a position would be very, very rare. Only this little, tiny bug in OliThink 5.7.0 helped us find this jewel.

Regards from Germany to Spain!

PS: Actually, this situation only happened, because of this bug. From OliThink 5.7.0's point of view 66...Be8 was a forced draw as its move generator didn't even include any under-promotions for pinned pawns. I wouldn't be surprised if this is the first and last position ever having this situation. Until, of course, there is another bug in another engine.

[chrisw]

Hello Oliver:

Hello together,
chess puzzle lovers will love this: A position from a real game where an under-promotion to bishop happens. And even better, a pinned pawn under-promoted.
If you ask me, this is a 1 in a million situation:

[d]4b3/1k1P4/1P6/1K3p2/5N2/8/8/8 w - - 1 67 bm dxe8=b

(Mate in 7 with underpromotion to bishop)
And here the complete game between Fruit 2.1 and OliThink 5.7.0:


[pgn]
[Event "?"]
[Site "?"]
[Date "2020.09.03"]
[Round "4256"]
[White "Fruit 2.1"]
[Black "OliThink 5.7.0"]
[Result "1-0"]

1. c3 e5 2. c4 Nc6 3. Qc2 Nf6 4. Nf3 e4 5. Ng5 d5 6. cxd5 Qxd5 7. h4 Nb4 8. Qd1
Qf5 9. d3 Bc5 10. Be3 exd3 11. exd3 Bxe3 12. fxe3 Ng4 13. Qd2 Qc5 14. Nc3 Qxe3+
15. Qxe3+ Nxe3 16. Kd2 f6 17. Nf3 Nxf1+ 18. Rhxf1 O-O 19. a3 Nc6 20. Nb5 Bf5
21. Nfd4 Nxd4 22. Nxd4 Bg4 23. Rae1 Rfe8 24. Nb5 Rxe1 25. Rxe1 c6 26. Nd6 b6
27. Rc1 c5 28. b4 cxb4 29. axb4 Rd8 30. Ne4 Be6 31. Rc7 Bd5 32. Ng3 g6 33. Ne2
Bxg2 34. Rxa7 Be4 35. d4 f5 36. Rc7 Bg2 37. Kc3 b5 38. Nf4 Bf3 39. Ne6 Re8
40. Ng5 Bd5 41. Nxh7 Re3+ 42. Kd2 Re6 43. Ng5 Rd6 44. Ke3 Rd8 45. Rc5 Kg7
46. Rxb5 Kh6 47. Nh3 Bc4 48. Rc5 Re8+ 49. Kf2 Re2+ 50. Kf3 Rc2 51. Nf4 g5
52. hxg5+ Kxg5 53. Nh3+ Kf6 54. Kf4 Bd3 55. Ke3 Bc4 56. Nf4 Bb3 57. Rxc2 Bxc2
58. b5 Ke7 59. d5 Kd6 60. b6 Bb3 61. Kd4 Ba2 62. Kc3 Kd7 63. Kb4 Kc8 64. Kb5 Kb7
65. d6 Bf7 66. d7 Be8 67. dxe8=B 1-0
[/pgn]

For information: OliThink 5.7.0 has a little bug, where it can't do underpromtions of pinned pawns. Promotion of pinned-pawns are already very rare, now who would ever think there was an underpromotion of a pinned pawn. An not artificially constructed, it's real.

It could only be detected because of that little bug in OliThink 5.7.0, after Fruit's move, it stalled. In OliThink 5.7.1 this bug is fixed.

Nice position from a real game! I did a little research about promotions and underpromotions seven years ago:

Some statistics about promotions and underpromotions.

Since I am not a programmer, my tool did not provide exact results but almost. I analyzed CCRL 40/40 database (1,172,820 games) because CCRL 40/4 has more games and the elapsed time would be higher. Anyway, I did small changes on my tool to search the right strings. Here is what I have found after 3342.0 seconds (0:55:42.0) on my old PC:

Code: Select all

CCRL-4040.[1172820].pgn
 
xa1=B:      10
xb1=B:      23
xc1=B:      19
xd1=B:      22
xe1=B:      18
xf1=B:      25
xg1=B:      10
xh1=B:       1
xa8=B:      14
xb8=B:      18
xc8=B:      33
xd8=B:      27
xe8=B:      22
xf8=B:      38
xg8=B:      17
xh8=B:       4
xa1=B+:      0
xb1=B+:      4
xc1=B+:      2
xd1=B+:      3
xe1=B+:      4
xf1=B+:      5
xg1=B+:      3
xh1=B+:      0
xa8=B+:      0
xb8=B+:      2
xc8=B+:      3
xd8=B+:      7
xe8=B+:      7
xf8=B+:      7
xg8=B+:      8
xh8=B+:      1
xa1=B#:      0
xb1=B#:      0
xc1=B#:      0
xd1=B#:      0
xe1=B#:      0
xf1=B#:      0
xg1=B#:      0
xh1=B#:      0
xa8=B#:      0
xb8=B#:      0
xc8=B#:      0
xd8=B#:      0
xe8=B#:      0
xf8=B#:      0
xg8=B#:      0
xh8=B#:      0
 
==============================
 
Nor checks neither checkmates:
 
a1    10
b1    19
c1    17
d1    19
e1    14
f1    20
g1     7
h1     1
a8    14
b8    16
c8    30
d8    20
e8    15
f8    31
g8     9
h8     3

I searched captures that were bishop underpromotions. Since I am not able to detect if the king of the promoting side was pinned, those numbers are meant to be understood as upper bounds. Most of those bishop underpromotions would be in positions where kings were not pinned indeed. Just to put the numbers in context, here are the results of an excellent tool called Joined after circa 30 minutes of run:

Code: Select all

joined -q -v64 CCRL-4040.[1172820].pgn
Scanning file CCRL-4040.[1172820].pgn containing 1307549190 bytes !

[...]

94.8%: Line 28511542, game 1110272, 149444568 moves, 4294022023 pos, max 745, 84
94.8%: Line 28514878, game 1110400, 149462923 moves, 4294563689 pos, max 745, 84
100.0%: Line 30077298, game 1172224, 157496289 moves, 235142570 pos, max 745, 84
100.0%: Line 30080475, game 1172352, 157512519 moves, 235627231 pos, max 745, 84
100.0%: Line 30083605, game 1172480, 157529369 moves, 236121831 pos, max 745, 84
100.0%: Line 30086644, game 1172608, 157544365 moves, 236559292 pos, max 745, 84
100.0%: Line 30089808, game 1172736, 157559958 moves, 237019031 pos, max 745, 84
Read 1172820 games with 157570821 moves, 30091940 lines, 1307549190 bytes !
Got max. 745 moves in game 1092971 before line 28075317 !
Got 237335240 legal moves in 158743641 positons !
Got max. 84 legal moves after move 116 in game 121733 line 3144196 !

Total move statistics:
Pawn moves = 32480351, Knight moves = 21658350, Bishop moves = 24066608
Rook moves = 35378214, Queen moves = 20149886, King moves = 25931391
Check moves = 10300013, Mate moves = 48889, Stalemate moves = 2032
Hit moves = 25093686, En passant moves = 78397, Pawn two moves = 7424753
Short castlings = 1901544, Long castlings = 192435
Promotion to queen = 183772, Promotion to rook = 10159
Promotion to bishop = 2757, Promotion to knight = 5437

Total game statistics:
White won = 404405, Drawn = 469663, Black won = 298752
Unknown result = 0, Illegal result = 0, Conflicting results = 0
White mated = 21399, White stalemated = 993
Black mated = 27490, Black stalemated = 1039

Number of games with different lengths:
 28:   225,  29:   272,  30:   231,  31:   366,  32:   348,  33:   382
 34:   434,  35:   446,  36:   504,  37:   502,  38:   526,  39:   606
 40:   655,  41:   788,  42:   752,  43:   720,  44:   794,  45:   838
 46:   919,  47:   954,  48:  1069,  49:  1109,  50:  1328,  51:  1283
 52:  1525,  53:  1549,  54:  1779,  55:  1739,  56:  1996,  57:  1964
 58:  2239,  59:  2140,  60:  2527,  61:  2412,  62:  2860,  63:  2772
 64:  3011,  65:  2919,  66:  3439,  67:  3237,  68:  3777,  69:  3723
 70:  4070,  71:  4051,  72:  4491,  73:  4387,  74:  4996,  75:  4994
 76:  5351,  77:  5154,  78:  5688,  79:  5649,  80:  6251,  81:  5781
 82:  6786,  83:  6488,  84:  7513,  85:  7751,  86:  8733,  87:  8935
 88: 10459,  89:  8193,  90:  8886,  91:  8489,  92:  9095,  93:  8820
 94:  9695,  95:  9089,  96: 10049,  97:  9650,  98: 10181,  99:  9834
100: 10519, 101: 10196, 102: 10923, 103: 10458, 104: 11192, 105: 10645
106: 11394, 107: 11026, 108: 11563, 109: 11086, 110: 11836, 111: 11080
112: 11799, 113: 11358, 114: 11808, 115: 11185, 116: 11802, 117: 11258
118: 11859, 119: 11306, 120: 11552, 121: 11128, 122: 35614, 123: 12203
124: 12605, 125: 11881, 126: 12160, 127: 11836, 128: 11961, 129: 11423
130: 11539, 131: 11288, 132: 11352, 133: 11007, 134: 10629, 135: 10540
136: 10360, 137: 10126, 138: 10092, 139:  9939, 140:  9611, 141:  9362
142:  9305, 143:  8790, 144: 10624, 145:  8623, 146:  8293, 147:  8015
148:  7810, 149:  7751, 150:  7596, 151:  7373, 152:  7132, 153:  6930
154:  6943, 155:  6457, 156:  6495, 157:  6191, 158:  6198, 159:  5943
160:  9132, 161:  5531, 162:  5489, 163:  5397, 164:  5383, 165:  5627
166:  5553, 167:  5539, 168:  5535, 169:  4734, 170:  4536, 171:  4300
172:  4149, 173:  4046, 174:  3907, 175:  3810, 176:  3707, 177:  3568
178:  3557, 179:  3444, 180:  3238, 181:  3222, 182:  3019, 183:  2964
184:  2835, 185:  2772, 186:  2787, 187:  2755, 188:  2615, 189:  2569
190:  2493, 191:  2478, 192:  2318, 193:  2441, 194:  2289, 195:  2319
196:  2185, 197:  2179, 198:  2094, 199:  2059, 200:  2058, 201:  1846
202:  1899, 203:  1926, 204:  1836, 205:  1777, 206:  1773, 207:  1772
208:  1722, 209:  1661, 210:  1722, 211:  1615, 212:  1619, 213:  1596
214:  1498, 215:  1501, 216:  1435, 217:  1427, 218:  1396, 219:  1399
220:  1357, 221:  1354, 222:  1280, 223:  1332, 224:  1281, 225:  1362
226:  1283, 227:  1304, 228:  1225, 229:  1264, 230:  1159, 231:  1137
232:  1124, 233:  1123, 234:  1114, 235:  1041, 236:  1097, 237:  1026
238:  1020, 239:   986, 240:  1088, 241:   964, 242:   983, 243:   928
244:   929, 245:  1004, 246:   935, 247:   913, 248:   912, 249:   880
250:   880, 251:   836, 252:   813, 253:   778, 254:   752, 255:   772
256:   773, 257:   679, 258:   689, 259:   743, 260:   712, 261:   700
262:   685, 263:   658, 264:   674, 265:   630, 266:   566, 267:   544
268:   578, 269:   578, 270:   548, 271:   505, 272:   565, 273:   558
274:   514, 275:   554, 276:   477, 277:   543, 278:   483, 279:   485
280:   416, 281:   464, 282:   446, 283:   425, 284:   419, 285:   378
286:   411, 287:   381, 288:   424, 289:   417, 290:   390, 291:   374
292:   362, 293:   354, 294:   397, 295:   347, 296:   371, 297:   378
298:   346, 299:   325, 300:   359, 301:   328, 302:   325, 303:   338
304:   317, 305:   305, 306:   324, 307:   306, 308:   303, 309:   300
310:   249, 311:   282, 312:   292, 313:   272, 314:   293, 315:   235
316:   260, 317:   260, 318:   259, 319:   261, 320:   303, 321:   268
322:   218, 323:   222, 324:   233, 325:   235, 326:   248, 327:   236
328:   223, 329:   249, 330:   214, 331:   191, 332:   196, 333:   206
334:   178, 335:   215, 336:   176, 337:   159, 338:   209, 339:   186
340:   190, 341:   170, 342:   174, 343:   172, 344:   157, 345:   173
346:   155, 347:   146, 348:   151, 349:   140, 350:   139, 351:   129
352:   154, 353:   144, 354:   129, 355:   111, 356:   137, 357:   113
358:   119, 359:   122, 360:   896, 361:   132, 362:   102, 363:    88
364:   113, 365:    94, 366:    72, 367:    89, 368:    93, 369:    98
370:    90, 371:    82, 372:    95, 373:    67, 374:    76, 375:    67
376:    80, 377:    82, 378:    66, 379:    67, 380:    81, 381:    76
382:    67, 383:    78, 384:    63, 385:    68, 386:    66, 387:    67
388:    59, 389:    65, 390:    65, 391:    58, 392:    64, 393:    61
394:    65, 395:    48, 396:    67, 397:    60, 398:    61, 399:    55
400:   186, 401:    66, 402:    47, 403:    46, 404:    48, 405:    69
406:    59, 407:    39, 408:    48, 409:    50, 410:    41, 411:    33
412:    37, 413:    31, 414:    44, 415:    52, 416:    40, 417:    42
418:    35, 419:    41, 420:    34, 421:    36, 422:    23, 423:    42
424:    30, 425:    40, 426:    27, 427:    28, 428:    42, 429:    32
430:    29, 431:    32, 432:    29, 433:    25, 434:    35, 435:    22
436:    30, 437:    33, 438:    27, 439:    35, 440:    22, 441:    29
442:    26, 443:    25, 444:    31, 445:    27, 446:    19, 447:    27
448:    19, 449:    23, 450:    25, 451:    21, 452:    24, 453:    20
454:    21, 455:    17, 456:    20, 457:    22, 458:    22, 459:    14
460:    14, 461:     9, 462:    17, 463:    14, 464:    11, 465:    22
466:    12, 467:    17, 468:    15, 469:    15, 470:    23, 471:    13
472:    12, 473:    14, 474:    13, 475:    14, 476:    16, 477:    18
478:    13, 479:    15, 480:    11, 481:    11, 482:    11, 483:    16
484:    14, 485:    16, 486:     9, 487:    15, 488:     8, 489:    11
490:    12, 491:    14, 492:     8, 493:    10, 494:    13, 495:    11
496:     9, 497:     6, 498:     9, 499:    13, 500:   147, 501:     4
502:     5, 503:     8, 504:     5, 505:     6, 506:     6, 507:     5
508:     4, 509:     5, 510:    13, 511:     4, 512:     2, 513:     4
514:    10, 515:     3, 516:     2, 517:    10, 518:     7, 519:     9
520:     7, 521:     4, 522:     5, 523:     4, 524:     8, 525:     2
526:     4, 527:     5, 528:     5, 529:     4, 530:     4, 531:     3
532:     2, 534:     3, 535:     2, 536:     3, 537:     4, 538:     3
539:     4, 540:     2, 541:     4, 542:     2, 543:     3, 544:     3
546:     2, 548:     3, 549:     3, 551:     4, 552:     1, 553:     2
554:     5, 555:     2, 556:     3, 557:     2, 558:     1, 559:     2
560:     1, 563:     2, 564:     3, 565:     5, 566:     3, 567:     1
568:     2, 570:     2, 573:     2, 574:     2, 575:     2, 576:     1
577:     3, 579:     1, 580:    11, 581:     1, 582:     1, 583:     2
585:     2, 588:     1, 589:     3, 592:     3, 593:     1, 598:     1
600:    18, 614:     1, 616:     1, 624:     1, 631:     1, 641:     1
657:     1, 691:     1, 702:     1, 718:     1, 745:     1

There were 2757 underpromotions to bishop in 157,570,821 moves (plies). Only 301 of them (more less) where after captures according to my tool. To avoid stalemates, those underpromotions must be without giving checks or checkmates, hence I searched them also and substracted from 301, finally obtaining 245 at most that ought to fulfill expectations. This means 245/(157,570,821) ~ 1/(643,146.2); further analysis of these 245 positions would show unpinned kings in most of the cases or even pieces that are going to be captured anyway (so maybe queening was possible without stalemating), so 1 in a million feels way short to me. More like 1 in 10 million or surely rarer as my wild guess.

Regards from Spain.

Ajedrecista.

Nice stats. I would guess in self-play the rarity will hold true, but switch to playing against a different opponent (that we assume does not have the same bug) and the effect of the adversarial search will be to find the fault at a way higher rate.

[OliverBr]

It's really funny. From Olithink 5.7.0's perspective 66...Be8 is really a draw:

Code: Select all

dep	score	nodes	time	(not shown:  tbhits	knps	seldep)
 37	  0.00 	140.1M	0:24.25	f7e8 f4d5 e8d7 b5c5 d7e8 d5f4 e8d7 c5d6 d7c6 d6c5 c6d7  
 36	  0.00 	115.6M	0:20.02	f7e8 f4d5 e8d7 b5c5 d7c8 c5d4 c8d7 d4e3 f5f4 e3f4 d7e6 f4e5 e6d5 e5d5 b7b6  
 35	  0.00 	101.9M	0:17.74	f7e8 f4d5 e8d7 b5c5 d7e6 d5f4 e6d7 f4d3 d7e6 d3f4  
 34	  0.00 	88.2M  	0:15.25	f7e8 f4d5 e8d7 b5c5 d7e6 d5f4 e6d7 f4d3 d7c8 c5b5 c8d7 b5c5  
 33	  0.00 	75.9M  	0:12.96	f7e8 f4d5 e8d7 b5c5 d7e6 d5f4 e6d7 c5d6 d7b5 f4d5 b5c6 d5e7 c6e4 d6e5 b7b6 e7f5 e4f3 f5d6 f3c6 e5d4 b6c7 d6e4 c6b5 d4c5 b5c4 c5c4  
 32	  0.00 	46.5M  	0:08.16	f7e8 f4d5 e8d7 b5c5 d7e6 c5d4 e6d5 d4d5 b7b6 d5e5 b6c6 e5f5  
 31	  0.00 	40.5M  	0:07.02	f7e8 f4d5 e8d7 b5c5 d7e6 d5c7 e6d7 c5d6 f5f4 d6d7 f4f3 c7d5 f3f2 d5e3 b7b6 d7e6 b6c7 e6d5 c7d7 d5e5 d7c6 e5f4 c6d6 f4f3 f2f1q e3f1  
 30	  0.00 	34.4M  	0:05.98	f7e8 f4d5 e8d7 b5c5 d7e6 d5c7 e6d7 c5d6 f5f4 d6d7 f4f3 c7d5 f3f2 d5e3 b7b6 d7e6 b6b7 e6e5 b7b8 e5d5 b8b7 d5e4 b7b8 e4d3 b8b7 d3e2 f2f1q e2f1  
 29	  0.00 	9.78M  	0:01.99	f7e8 f4d5 e8d7 b5c5 d7e6 d5c7 e6d7 c7d5  
 28	  0.00 	7.73M  	0:01.64	f7e8 f4d5 e8d7 b5c5 d7e6 d5c7 e6d7 c7d5  
 27	  0.00 	1.23M  	0:00.24	f7e8 f4d5 e8d7 b5c5 d7e6 d5c7 e6d7 c7d5  
 26	  0.00 	786640	0:00.15	f7e8 f4d5 e8d7 b5c5 d7e6 d5c7 e6d7 c7d5  
 25	  0.00 	513808	0:00.10	f7e8 f4d5 e8d7 b5c5 d7e6 d5c7 e6d7 c7d5  
 24	  0.00 	241357	0:00.04	f7e8 f4d5 e8d7 b5c5 d7c6 d5f4 c6e4 f4e6 e4h1 e6f4 h1e4  
 23	  0.00 	166859	0:00.03	f7e8 f4d5 e8d7 b5c5 d7c6 d5f4 c6e4 f4e6 e4h1 e6f4 h1e4  
 22	  0.00 	114916	0:00.02	f7e8 f4d5 e8d7 b5c5 d7c6 d5f4 c6d7 f4d5  
 21	  0.00 	93330  	0:00.01	f7e8 f4d5 e8d7 b5c5 d7c6 d5f4 c6d7 f4d5  
 20	  0.00 	69340  	0:00.01	f7e8 f4d5 e8d7 b5c5 d7c6 d5f4 c6d7 f4d5  
 19	  0.00 	54352  	0:00.01	f7e8 f4d5 e8d7 b5c5 d7c6 d5f4 c6e4 f4e2 e4d3 e2f4 d3e4  
 18	  0.00 	37185  	0:00.00	f7e8 f4d5 e8d7 b5c5 d7c6 d5f4 c6e4 f4e2 e4d3 e2f4 d3e4  
 17	  0.00 	28142  	0:00.00	f7e8 f4d5 e8d7 b5c5 d7c6 d5f4 c6e4 f4e2 e4d3 e2f4 d3e4  
 16	  0.00 	21127  	0:00.00	f7e8 f4d5 e8d7 b5c5 d7c6 d5f4 c6e4 f4e2 e4d3 e2f4 d3e4  
 15	  0.00 	15332  	0:00.00	f7e8 f4d5 e8d7 b5c5 d7c6 d5f4 c6e4 f4e2 e4d3 e2f4 d3e4  
 14	  0.00 	11585  	0:00.00	f7e8 f4d5 e8d7 b5c5 d7c6 d5f4 c6e4 f4e2 e4d3 e2f4 d3e4  
 13	  0.00 	9242    	0:00.00	f7e8 f4d5 e8d7 b5c5 d7c6 d5f4 c6e4 f4e2 e4d3 e2f4 d3e4  
 12	  0.00 	7435    	0:00.00	f7e8 f4d5 e8d7 b5c5 d7c6 d5f4 c6e4 f4e2 e4d3 e2f4 d3e4  
 11	  0.00 	5978    	0:00.00	f7e8 f4d5 e8d7 b5c5 d7c6 d5f4 c6e4 f4e2 e4d3 e2f4 d3e4  
 10	  0.00 	4719    	0:00.00	f7e8 f4d5 e8d7 b5c5 d7c6 d5f4 c6e4 f4e2 e4d3 e2f4 d3e4  
  9	 -0.14 	3677    	0:00.00	f7e8 f4d5 e8d7 b5c5 d7c6 d5f4 c6e4 f4e2 b7c8 e2c3  
  8	 -0.22 	2602    	0:00.00	f7e8 f4d5 e8d7 b5c5 d7c6 d5f4 c6d7 f4d3 d7c6  
  7	 -0.10 	1720    	0:00.00	f7e8 b5c5 e8d7 f4d5 d7c6 d5b4 c6f3  
  6	 -0.22 	1119    	0:00.00	f7e8 b5c5 e8d7 f4d5 d7c6 d5c3  
  5	 -0.46 	771      	0:00.00	f7e8 b5c5 e8d7 f4d5 b7a6  
  4	 -0.48 	549      	0:00.00	f7e8 b5c5 e8d7 f4d5  
  3	 -0.51 	269      	0:00.00	f7e8 f4d5 e8d7 b5c4  
  2	 -0.51 	184      	0:00.00	f7e8 f4d5  
  1	 -10.44 	36        	0:00.00	f7d5  

Of course, bugfree 5.7.4 sees this different:

Code: Select all

64	   #-7 	161.5M	0:19.93	f7e8 d7e8b b7c8 f4e6 c8b7 e8c6 b7b8 b6b7 f5f4 b5b6 f4f3 e6c7 f3f2 c7a6  
 63	   #-7 	156.5M	0:19.35	f7e8 d7e8b b7c8 f4e6 c8b7 e8c6 b7b8 b6b7 f5f4 b5b6 f4f3 e6c7 f3f2 c7a6  
 62	   #-7 	151.5M	0:18.82	f7e8 d7e8b b7c8 f4e6 c8b7 e8c6 b7b8 b6b7 f5f4 b5b6 f4f3 e6c7 f3f2 c7a6  
 61	   #-7 	145.4M	0:18.17	f7e8 d7e8b b7c8 f4e6 c8b7 e8c6 b7b8 b6b7 f5f4 b5b6 f4f3 e6c7 f3f2 c7a6  
 60	   #-7 	139.4M	0:17.56	f7e8 d7e8b b7c8 f4e6 c8b7 e8c6 b7b8 b6b7 f5f4 b5b6 f4f3 e6c7 f3f2 c7a6  
 59	   #-7 	134.8M	0:17.00	f7e8 d7e8b b7c8 f4e6 c8b7 e8c6 b7b8 b6b7 f5f4 b5b6 f4f3 e6c7 f3f2 c7a6  
 58	   #-7 	129.9M	0:16.50	f7e8 d7e8b b7c8 f4e6 c8b7 e8c6 b7b8 b6b7 f5f4 b5b6 f4f3 e6c7 f3f2 c7a6  
 57	   #-7 	124.3M	0:15.89	f7e8 d7e8b b7c8 f4e6 c8b7 e8c6 b7b8 b6b7 f5f4 b5b6 f4f3 e6c7 f3f2 c7a6  
 56	   #-7 	119.1M	0:15.31	f7e8 d7e8b b7c8 f4e6 c8b7 e8c6 b7b8 b6b7 f5f4 b5b6 f4f3 e6c7 f3f2 c7a6  
 55	   #-7 	114.7M	0:14.79	f7e8 d7e8b b7c8 f4e6 c8b7 e8c6 b7b8 b6b7 f5f4 b5b6 f4f3 e6c7 f3f2 c7a6  
 54	   #-7 	109.9M	0:14.26	f7e8 d7e8b b7c8 f4e6 c8b7 e8c6 b7b8 b6b7 f5f4 b5b6 f4f3 e6c7 f3f2 c7a6  
 53	   #-7 	104.9M	0:13.71	f7e8 d7e8b b7c8 f4e6 c8b7 e8c6 b7b8 b6b7 f5f4 b5b6 f4f3 e6c7 f3f2 c7a6  
 52	   #-7 	100.6M	0:13.22	f7e8 d7e8b b7c8 f4e6 c8b7 e8c6 b7b8 b6b7 f5f4 b5b6 f4f3 e6c7 f3f2 c7a6  
 51	   #-7 	96.3M  	0:12.71	f7e8 d7e8b b7c8 f4e6 c8b7 e8c6 b7b8 b6b7 f5f4 b5b6 f4f3 e6c7 f3f2 c7a6  
 50	   #-7 	91.8M  	0:12.20	f7e8 d7e8b b7c8 f4e6 c8b7 e8c6 b7b8 b6b7 f5f4 b5b6 f4f3 e6c7 f3f2 c7a6  
 49	   #-7 	87.3M  	0:11.68	f7e8 d7e8b b7c8 f4e6 c8b7 e8c6 b7b8 b6b7 f5f4 b5b6 f4f3 e6c7 f3f2 c7a6  
 48	   #-7 	83.1M  	0:11.20	f7e8 d7e8b b7c8 f4e6 c8b7 e8c6 b7b8 b6b7 f5f4 b5b6 f4f3 e6c7 f3f2 c7a6  
 47	   #-7 	79.5M  	0:10.76	f7e8 d7e8b b7c8 f4e6 c8b7 e8c6 b7b8 b6b7 f5f4 b5b6 f4f3 e6c7 f3f2 c7a6  
 46	   #-7 	75.5M  	0:10.29	f7e8 d7e8b b7c8 f4e6 c8b7 e8c6 b7b8 b6b7 f5f4 b5b6 f4f3 e6c7 f3f2 c7a6  
 45	   #-7 	71.5M  	0:09.80	f7e8 d7e8b b7c8 f4e6 c8b7 e8c6 b7b8 b6b7 f5f4 b5b6 f4f3 e6c7 f3f2 c7a6  
 44	   #-7 	67.9M  	0:09.38	f7e8 d7e8b b7c8 f4e6 c8b7 e8c6 b7b8 b6b7 f5f4 b5b6 f4f3 e6c7 f3f2 c7a6  
 43	   #-7 	64.5M  	0:08.95	f7e8 d7e8b b7c8 f4e6 c8b7 e8c6 b7b8 b6b7 f5f4 b5b6 f4f3 e6c7 f3f2 c7a6  
 42	   #-7 	60.9M  	0:08.50	f7e8 d7e8b b7c8 f4e6 c8b7 e8c6 b7b8 b6b7 f5f4 b5b6 f4f3 e6c7 f3f2 c7a6  
 41	   #-7 	57.5M  	0:08.08	f7e8 d7e8b b7c8 f4e6 c8b7 e8c6 b7b8 b6b7 f5f4 b5b6 f4f3 e6c7 f3f2 c7a6  
 40	   #-7 	54.4M  	0:07.69	f7e8 d7e8b b7c8 f4e6 c8b7 e8c6 b7b8 b6b7 f5f4 b5b6 f4f3 e6c7 f3f2 c7a6  
 39	   #-7 	51.1M  	0:07.26	f7e8 d7e8b b7c8 f4e6 c8b7 e8c6 b7b8 b6b7 f5f4 b5b6 f4f3 e6c7 f3f2 c7a6  
 38	   #-7 	47.9M  	0:06.84	f7e8 d7e8b b7c8 f4e6 c8b7 e8c6 b7b8 b6b7 f5f4 b5b6 f4f3 e6c7 f3f2 c7a6  
 37	   #-7 	44.7M  	0:06.42	f7e8 d7e8b b7c8 f4e6 c8b7 e8c6 b7b8 b6b7 f5f4 b5b6 f4f3 e6c7 f3f2 c7a6  
 36	   #-7 	41.9M  	0:06.06	f7e8 d7e8b b7c8 f4e6 c8b7 e8c6 b7b8 b6b7 f5f4 b5b6 f4f3 e6c7 f3f2 c7a6  
 35	   #-7 	38.9M  	0:05.65	f7e8 d7e8b b7c8 f4e6 c8b7 e8c6 b7b8 b6b7 f5f4 b5b6 f4f3 e6c7 f3f2 c7a6  
 34	   #-7 	35.9M  	0:05.25	f7e8 d7e8b b7c8 f4e6 c8b7 e8c6 b7b8 b6b7 f5f4 b5b6 f4f3 e6c7 f3f2 c7a6  
 33	   #-7 	33.1M  	0:04.87	f7e8 d7e8b b7c8 f4e6 c8b7 e8c6 b7b8 b6b7 f5f4 b5b6 f4f3 e6c7 f3f2 c7a6  
 32	   #-7 	30.6M  	0:04.55	f7e8 d7e8b b7c8 f4e6 c8b7 e8c6 b7b8 b6b7 f5f4 b5b6 f4f3 e6c7 f3f2 c7a6  
 31	   #-7 	28.0M  	0:04.20	f7e8 d7e8b b7c8 f4e6 c8b7 e8c6 b7b8 b6b7 f5f4 b5b6 f4f3 e6c7 f3f2 c7a6  
 30	   #-7 	25.5M  	0:03.86	f7e8 d7e8b b7c8 f4e6 c8b7 e8c6 b7b8 b6b7 f5f4 b5b6 f4f3 e6c7 f3f2 c7a6  
 29	   #-7 	22.9M  	0:03.51	f7e8 d7e8b b7c8 f4e6 c8b7 e8c6 b7b8 b6b7 f5f4 b5b6 f4f3 e6c7 f3f2 c7a6  
 28	   #-7 	20.7M  	0:03.21	f7e8 d7e8b b7c8 f4e6 c8b7 e8c6 b7b8 b6b7 f5f4 b5b6 f4f3 e6c7 f3f2 c7a6  
 27	   #-7 	18.5M  	0:02.91	f7e8 d7e8b b7c8 f4e6 c8b7 e8c6 b7b8 b6b7 f5f4 b5b6 f4f3 e6c7 f3f2 c7a6  
 26	   #-7 	16.2M  	0:02.60	f7e8 d7e8b b7c8 f4e6 c8b7 e8c6 b7b8 b6b7 f5f4 b5b6 f4f3 e6c7 f3f2 c7a6  
 25	   #-7 	14.1M  	0:02.32	f7e8 d7e8b b7c8 f4e6 c8b7 e8c6 b7b8 b6b7 f5f4 b5b6 f4f3 e6c7 f3f2 c7a6  
 24	   #-7 	12.2M  	0:02.05	f7e8 d7e8b b7c8 f4e6 c8b7 e8c6 b7b8 b6b7 f5f4 b5b6 f4f3 e6c7 f3f2 c7a6  
 23	   #-7 	10.2M  	0:01.77	f7e8 d7e8b b7c8 f4e6 c8b7 e8c6 b7b8 b6b7 f5f4 b5b6 f4f3 e6c7 f3f2 c7a6  
 22	   #-7 	8.62M  	0:01.53	f7e8 d7e8b b7c8 f4e6 c8b7 e8c6 b7b8 b6b7 f5f4 b5b6 f4f3 e6c7 f3f2 c7a6  
 21	   #-7 	7.25M  	0:01.32	f7e8 d7e8b b7c8 f4e6 c8b7 e8c6 b7b8 b6b7 f5f4 b5b6 f4f3 e6c7 f3f2 c7a6  
 20	   #-7 	5.71M  	0:01.06	f7e8 d7e8b b7c8 f4e6 c8b7 e8c6 b7b8 b6b7 f5f4 b5b6 f4f3 e6c7 f3f2 c7a6  
 19	   #-7 	4.15M  	0:00.78	f7e8 d7e8b b7c8 f4e6 c8b7 e8c6 b7b8 b6b7 f5f4 b5b6 f4f3 e6c7 f3f2 c7a6  
 18	   #-7 	3.40M  	0:00.65	f7e8 d7e8b b7c8 f4e6 c8b7 e8c6 b7b8 b6b7 f5f4 b5b6 f4f3 e6c7 f3f2 c7a6  
 17	   #-8 	2.14M  	0:00.41	f7e8 d7e8b b7c8 b5c6 c8d8 b6b7 d8e8 b7b8q e8f7 b8h8 f7e7 h8g7 e7e8 g7g8 e8e7 f4d5  
 16	   #-8 	1.28M  	0:00.25	f7e8 d7e8b b7c8 b5c6 c8d8 b6b7 d8e8 b7b8q e8f7 b8h8 f7e7 h8g7 e7e8 g7g8 e8e7 f4d5  
 15	   #-8 	758487	0:00.15	f7e8 d7e8b b7c8 b5c6 c8d8 b6b7 d8e8 b7b8q e8f7 b8h8 f7e7 h8g7 e7e8 g7g8 e8e7 f4d5  
 14	   #-8 	441232	0:00.09	f7e8 d7e8b b7c8 b5c6 c8d8 b6b7 d8e8 b7b8q e8f7 b8h8 f7e7 h8g7 e7e8 g7g8 e8e7 f4d5  
 13	   #-8 	320902	0:00.06	f7e8 d7e8b b7c8 b5c6 c8d8 b6b7 d8e8 b7b8q e8f7 b8h8 f7e7 h8g7 e7e8 g7g8 e8e7  
 12	 -18.66 	185418	0:00.04	f7e8 d7e8b b7c8 b5c6 c8d8 e8d7 d8e7 b6b7 e7f6 b7b8q f6g7 d7f5 g7h6  
 11	 -17.00 	85889  	0:00.02	f7e8 d7e8b b7c8 b5c6 c8d8 e8d7 d8e7 b6b7 e7f6 b7b8q f6g5 b8c7  
 10	 -17.14 	59488  	0:00.01	f7e8 d7e8b b7c8 b5c6 c8d8 e8d7 d8e7 b6b7 e7f6 b7b8q f6g5  
  9	 -9.21 	12567  	0:00.00	f7e8 d7e8b b7b8 e8d7 b8a8 d7f5 a8b8 f5e4 b8c8  
  8	 -9.21 	7250    	0:00.00	f7e8 d7e8b b7a8 e8g6 a8b8 g6f5 b8b7 f5e4 b7c8  
  7	 -9.05 	3624    	0:00.00	f7e8 d7e8b b7a8 e8c6 a8b8 c6d5 b8c8 d5e6 c8b7  
  6	 -8.33 	2335    	0:00.00	f7e8 d7e8b b7a8 e8c6 a8b8 c6d5 b8c8  
  5	 -8.35 	1682    	0:00.00	f7e8 d7e8b b7a8 e8c6 a8b8 b5c4  
  4	 -7.92 	1000    	0:00.00	f7e8 d7e8b b7b8 b5c4  
  3	 -7.76 	592      	0:00.00	f7e8 d7e8b b7b8  
  2	 -10.18 	333      	0:00.00	f7e8 d7e8r  
  1	 -6.52 	47        	0:00.00	f7c4 b5c4  
  0	#