Tablebase suggestion

[Ajedrecista]

Hello:

[...]

The 8-men positions with 1 opposing pair have been computed by Marc Bourzutschky (DTC metric) and are accessible here:
https://op1-tables.info/

8-men with 1 opposing pair only needs 82.5 GB of RAM with 1 byte per position if you split it up in pawn slices with the pair fixed, so it does not need a big machine.
9-men with 2 opposing pairs should only need 1.2 GB of RAM with 1 byte per position.
Why not go further and do 10-men with 3 opposing pairs, 11-men with 4 opposing pairs and 12-men with 5 opposing pairs (and 2 kings).

[...]

I am very pleased to say again that Op1 8-man EGTB work like a charm. I composed an entertaining, challenging position to play on your own in either side, though generally without only moves to find. Engines find it easy, but is full of swindles, stalemate threats, queening threats, pins and even a sort of desperado queen (instead of the more usual desperado rook):

[d]8/3Q4/8/8/8/5p2/2pn1P1p/3k3K w - - 0 1

Only 1.- Qa4! draws, pinning the passed pawn. Then, there are only three moves that draw: 1.- ..., Nb1, 1.- ..., Ne4 and 1.- ..., Nf1 (this one with stalemate threats). I post some sidelines in three sepatated PGN under the same PGN tag, for saving space in the post. I annotate with exclamation marks (!) in only moves and question marks (?) in the moves that lose points in result (win to draw or lose; or draw to lose):

[pgn][Event ""]
[Site ""]
[Date "2026.05.09"]
[SetUp "1"]
[FEN "8/3Q4/8/8/8/5p2/2pn1P1p/3k3K w - - 0 1"]
[Result "1/2-1/2"]

1.Qa4! Nb1 2.Qd4+ Nd2! (2...Kc1? 3.Kxh2! Nd2 4.Kg3 Nb3 (4...Kd1 5.Qa4! Kc1 6.Qa1+ Nb1 7.Kxf3 1-0) 5.Qc3! Nd2 6.Qa1+ Nb1 7.Kxf3 1-0) 3.Qa4! 1/2-1/2

[Event ""]
[Site ""]
[Date "2026.05.09"]
[SetUp "1"]
[FEN "8/3Q4/8/8/8/5p2/2pn1P1p/3k3K w - - 0 1"]
[Result "1/2-1/2"]

1.Qa4! Ne4 2.Qxe4 (2.Qd4+ (2.Kxh2 Nxf2! 3.Qxc2+ Kxc2! 4.Kg3! 1/2-1/2) Nd2! 3.Qa4! 1/2-1/2) c1=Q! 3.Kxh2 (3.Qd3+ Ke1 (3...Qd2 4.Qxf3+ (4.Qxd2+? Kxd2! 5.Kxh2 Ke1 0-1) Ke1! (4.Kc2? Qf5+ ({(DTM 80 moves)}) 1-0) 1/2-1/2) 4.Qxf3 Kd2+ 5.Kxh2! Qc7+! 6.Qg3 Qh7+! 1/2-1/2) Qc7+ (3...Qc3 4.Qb1+ Ke2 5.Qe4+ Kxf2 6.Qh4! Kf1 7.Qh3+ Kf2 8.Qg2+ fxg2 1/2-1/2) 4.Kh1 (4.Kg1? Qg7+! 0-1) 1/2-1/2

[Event ""]
[Site ""]
[Date "2026.05.09"]
[SetUp "1"]
[FEN "8/3Q4/8/8/8/5p2/2pn1P1p/3k3K w - - 0 1"]
[Result "1/2-1/2"]

1.Qa4! Nf1 2.Qxc2+ (2.Qa1+ (2.Qd4+ Nd2 (2...Kc1 (2...Ke1? 3.Qc3 Kd1 4.Qxf3+! 1-0) 3.Qa1+ Kd2 4.Qe1+ Kxe1! (4...Kd3? 5.Qxf1! Kd2 6.Kxh2! c1=Q 7.Qxc1+! Kxc1 8.Kg3 1-0) 1/2-1/2) 3.Qa4! 1/2-1/2) c1=Q 3.Qxc1+ Kxc1! (3...Ke2? 4.Qa1 Kxf2 (4...Nd2 5.Kxh2 Kxf2 6.Qe5 1-0) 5.Qd1 1-0) 1/2-1/2) Kxc2! (2...Ke1? 3.Qd3 (3.Qe4+ Kxf2 4.Qd3 1-0) Nd2 4.Kxh2 1-0) 1/2-1/2[/pgn]

Regards from Spain.

Ajedrecista.