Deep Horizons

A couple of weeks ago, I had a post about Tablebases and Fortresses (March 2020), two types of positions that create problems for chess engines. These were collected on the Fishcooking forum.

Another, smaller set of positions can be found on the Talkchess forum, in a thread titled Hard-Talkchess-2020 set, final release (talkchess.com). These are difficult ('Hard') positions where the choice of best variation lies beyond the current computational limits of the best engines.

1B1K1k2/4N2p/3pP1pP/6p1/p7/3N2b1/2r2p2/8 w

This Lichess diagram shows the first position in the set. The key move is 1.Nc6. Although I didn't analyze it with an engine, it looks like the Black King is destined to be chased around the board after e6-e7-e8Q.

For more about the EPD format of the 'Talkchess 2020 set', see Extended Position Description (chessprogramming.org). For those of us currently under coronavirus confinement, the positions in this and the previous 'TBs & Fortresses' post might help to pass the time.