It seems at least some of the 7-men TBs can be produced. Here is the current code: https://github.com/noobpwnftw/tb/tree/7-men, and here are all 3-6 men + some 7 men TBs I've generated so far: ftp://112.73.74.24/pub/syzygy/

However, it failed at this line https://github.com/noobpwnftw/tb/blob/a ... ute.c#L552 when generating certain piece combinations, for example KQQRBNvK.

Logs here:

Code: Select all

```
./rtbgen -t 128 --disk KQQRBNvK
Found 533 tablebases.
number of threads = 128
Initialising broken positions.
time taken = 0:31.838
Calculating white captures.
time taken = 0:17.572
Calculating black captures.
time taken = 0:04.970
time taken = 0:06.162
time taken = 0:06.358
time taken = 0:10.668
time taken = 0:13.659
time taken = 0:26.850
Calculating mate positions.
time taken = 1:28.989
Iteration 1 ... done.
Iteration 2 ... done.
Iteration 3 ... done.
Iteration 4 ... done.
Iteration 5 ... done.
Iteration 6 ...
########## KQQRBNvK ##########
White to move:
50353929224 positions win in 1 ply.
19485324695 positions win in 2 ply.
28225943789 positions win in 3 ply.
1549221184 positions win in 4 ply.
243517440 positions win in 5 ply.
508342 positions win in 6 ply.
1236 positions win in 7 ply.
99858445910 positions are wins.
10832 positions are draws.
0 positions are losses.
Black to move:
0 positions are wins.
13398181230 positions are draws.
337200714690 positions are losses.
40252520554 positions lose in 0 ply.
23613041816 positions lose in 1 ply.
130186914772 positions lose in 2 ply.
54678294580 positions lose in 3 ply.
81532772392 positions lose in 4 ply.
5908260412 positions lose in 5 ply.
1026861706 positions lose in 6 ply.
2041596 positions lose in 7 ply.
6862 positions lose in 8 ply.
Longest win for white: 8 ply; 8/Q1R5/8/8/3N4/2B5/5k2/QK6 b - -
tb_size = 196209130320
find optimal permutation for wtm / wdl
[ 0] order: 2; perm: 2 3 4 6 14 5; 8000
[ 1] order: 2; perm: 2 4 3 6 14 5; 8011
[ 2] order: 2; perm: 2 6 3 4 14 5; 8000
[ 3] order: 2; perm: 2 14 3 4 6 5; 8000
[ 4] order: 2; perm: 3 2 4 6 14 5; 8000
[ 5] order: 2; perm: 4 2 3 6 14 5; 8012
[ 6] order: 2; perm: 6 2 3 4 14 5; 8000
[ 7] order: 2; perm: 14 2 3 4 6 5; 8000
[ 8] order: 2; perm: 3 4 2 6 14 5; 8011
[ 9] order: 2; perm: 3 6 2 4 14 5; 8000
[10] order: 2; perm: 3 14 2 4 6 5; 8000
[11] order: 2; perm: 4 3 2 6 14 5; 8006
[12] order: 2; perm: 6 3 2 4 14 5; 8000
[13] order: 2; perm: 14 3 2 4 6 5; 8000
[14] order: 2; perm: 4 6 2 3 14 5; 8000
[15] order: 2; perm: 4 14 2 3 6 5; 8000
[16] order: 2; perm: 6 4 2 3 14 5; 8000
[17] order: 2; perm: 14 4 2 3 6 5; 8000
[18] order: 2; perm: 6 14 2 3 4 5; 8000
[19] order: 2; perm: 14 6 2 3 4 5; 8000
[20] order: 3; perm: 3 5 6 2 4 14; 8000
[21] order: 3; perm: 6 5 14 3 2 4; 8000
[22] order: 3; perm: 14 5 6 3 2 4; 8000
[23] order: 3; perm: 2 5 6 14 3 4; 8000
[24] order: 3; perm: 4 5 6 14 2 3; 8000
[25] order: 3; perm: 5 6 2 4 3 14; 8000
[26] order: 3; perm: 5 14 2 4 3 6; 8000
[27] order: 3; perm: 5 2 6 14 3 4; 8000
[28] order: 3; perm: 5 3 4 6 2 14; 8000
[29] order: 3; perm: 5 4 6 2 3 14; 8000
[ 0] order: 2; perm: 2 3 6 4 14 5; 8000
[ 1] order: 2; perm: 2 3 14 4 6 5; 8000
[ 2] order: 2; perm: 2 4 6 3 14 5; 8000
[ 3] order: 2; perm: 2 4 14 3 6 5; 8000
[ 4] order: 2; perm: 2 6 4 3 14 5; 8000
[ 5] order: 2; perm: 2 14 4 3 6 5; 8000
[ 6] order: 2; perm: 2 6 14 3 4 5; 8000
[ 7] order: 2; perm: 2 14 6 3 4 5; 8005
[ 8] order: 3; perm: 2 4 5 6 14 3; 8000
[ 9] order: 3; perm: 2 3 5 6 4 14; 8000
[10] order: 3; perm: 2 6 5 3 4 14; 8000
[11] order: 3; perm: 2 14 5 3 4 6; 8000
[12] order: 3; perm: 2 5 14 6 3 4; 8000
[13] order: 3; perm: 2 5 3 6 4 14; 8000
[14] order: 3; perm: 2 5 4 3 6 14; 8000
Segmentation fault
```

I think the current piece encoding/decoding cannot handle cases of KKQRBN+X(which did not exist in 6 men).

I recall there was a thread here where its author

**Ronald**explained the detailed mechanisms with

**mcostalba**, but no luck with the search... any enlightenment is appreciated.