Hello Mike:
MikeB wrote:[...] Real world, from real games , not proof games, the record as far I know is 79 moves. I performed a search once , using a move generator on 1 million games and found a game with 78 possible moves . I posted the game here, years ago - maybe 10 to 13 years ago.
The real game record:
https://timkr.home.xs4all.nl/records/re ... d%20pieces
I downloaded CCRL 40/4 games (CCRL-404.[2047025].pgn, so 2047025 games) and I found positions with perft(1) > 79. There is at least one position in this PGN with perft(1) = 85 because I saw that info while the fantastic tool
joined was running, before it was overwritten by other position with perft(1) = 89 and later by others with perft(1) = 98, perft(1) = 102 and perft(1) = 124. There might be other positions found later with 79 < perft(1) =< 124:
Code: Select all
.\joined>joined -h
Illegal option: h !
Usage: joined [<*.PGN, *.FEN or *.EPD file>] [-<options>]
Legal options are:
-p : Print messages to both stderr and stdout
-q : Quit after scanning input file
-r : Initial value for random algorithm
-s : Print messages only to stdout
-v<number>: Set verbose level to <number> (default 4)
The numbers may be added. The numbers are:
1: Print PGN
2: Calculate number of legal moves in all positions
4: Print progress (default)
8: Print all warnings
16: Check PGN
32: Report result = '*'
64: Get statistics on all types of moves
***** Error exit *****
.\joined>joined -q -v6 CCRL-404.[2047025].pgn
Scanning file CCRL-404.[2047025].pgn containing 2324578752 bytes !
[...]
Read 2047025 games with 282012002 moves, 53150521 lines, 2324578752 bytes !
Got max. 799 moves in game 1013473 before line 26659054 !
Got 3536229011 legal moves in 284059027 positons !
Got max. 124 legal moves after move 288 in game 892029 line 23469623 !
Verbose level -v6 is 2 + 4 = 6 ('Calculate number of legal moves in all positions' and 'Print progress').
Since I can only track the position with the maximum[perft(1)], the game where it arose is the following one:
The position with perft(1) = 124 is the next one just after 288 plies, as reported by
joined:
[d]5Q2/1QRB3k/4R3/3QQ3/3Q4/4Q3/4QK2/8 w - - 3 145
Which perft(1) = 124 was verified by
JetChess perft counter:
Code: Select all
JetChess 1.0.0.0:
5Q2/1QRB3k/4R3/3QQ3/3Q4/4Q3/4QK2/8 w - - 3 145
perft(1) = 124
--------------
1 Qe2-d3
2 Qe2-c4
3 Qe2-b5
4 Qe2-a6
5 Qe2-f3
6 Qe2-g4
7 Qe2-h5
8 Qe2-f1
9 Qe2-d1
10 Qe2-d2
11 Qe2-c2
12 Qe2-b2
13 Qe2-a2
14 Qe2-e1
15 Qe3-f4
16 Qe3-g5
17 Qe3-h6
18 Qe3-d2
19 Qe3-c1
20 Qe3-e4
21 Qe3-f3
22 Qe3-g3
23 Qe3-h3
24 Qe3-d3
25 Qe3-c3
26 Qe3-b3
27 Qe3-a3
28 Qd4-c5
29 Qd4-b6
30 Qd4-a7
31 Qd4-c3
32 Qd4-b2
33 Qd4-a1
34 Qd4-e4
35 Qd4-f4
36 Qd4-g4
37 Qd4-h4
38 Qd4-c4
39 Qd4-b4
40 Qd4-a4
41 Qd4-d3
42 Qd4-d2
43 Qd4-d1
44 Qd5-c6
45 Qd5-e4
46 Qd5-f3
47 Qd5-g2
48 Qd5-h1
49 Qd5-c4
50 Qd5-b3
51 Qd5-a2
52 Qd5-d6
53 Qd5-c5
54 Qd5-b5
55 Qd5-a5
56 Qe5-d6
57 Qe5-f6
58 Qe5-g7
59 Qe5-h8
60 Qe5-f4
61 Qe5-g3
62 Qe5-h2
63 Qe5-f5
64 Qe5-g5
65 Qe5-h5
66 Qe5-e4
67 Qb7-a8
68 Qb7-c8
69 Qb7-c6
70 Qb7-a6
71 Qb7-b8
72 Qb7-a7
73 Qb7-b6
74 Qb7-b5
75 Qb7-b4
76 Qb7-b3
77 Qb7-b2
78 Qb7-b1
79 Qf8-g7
80 Qf8-h6
81 Qf8-e7
82 Qf8-d6
83 Qf8-c5
84 Qf8-b4
85 Qf8-a3
86 Qf8-g8
87 Qf8-h8
88 Qf8-e8
89 Qf8-d8
90 Qf8-c8
91 Qf8-b8
92 Qf8-a8
93 Qf8-f7
94 Qf8-f6
95 Qf8-f5
96 Qf8-f4
97 Qf8-f3
98 Re6-e7
99 Re6-e8
100 Re6-f6
101 Re6-g6
102 Re6-h6
103 Re6-d6
104 Re6-c6
105 Re6-b6
106 Re6-a6
107 Rc7-c8
108 Rc7-c6
109 Rc7-c5
110 Rc7-c4
111 Rc7-c3
112 Rc7-c2
113 Rc7-c1
114 Bd7-c8
115 Bd7-e8
116 Bd7-c6
117 Bd7-b5
118 Bd7-a4
119 Kf2-g2
120 Kf2-f3
121 Kf2-g3
122 Kf2-e1
123 Kf2-f1
124 Kf2-g1
It is a real game since it is not a composition, although the level of the engines was really low. To force a threefold repetition with the winning side in a KQQQQQQRRB-vs-k position has its merit.
This task can be repeated with CCRL 40/40 games, CEGT, SSDF and so on. I chose CCRL 40/4 for its high amount of games.
Regards from Spain.
Ajedrecista.