#Stockfish endgame tablebase update#
#Stockfish endgame tablebase software#

My results suggest that we may already be at or close to this saturation point: The longest winning line for 8-man endgames without pawns appears to be вЂњonlyвЂќ 400 moves.ДЄfter generating about 15% of the pawnless endings IвЂ™m quite confident to have captured the longest ones. An important question is at what point the chess board becomes so crowded that adding more pieces does not lead to longer winning lines due to the increased likelihood of shortening captures. One key discovery by YKMB is the so far longest winning line of 517 moves in the 7-man endgame kqnkrbn, more than twice the length of the previous record of 243 moves in the 6-man endgame krnknn. Here are some passages from his article on the issue: However, MarcвЂ™s progressive results suggest that the Law may not hold up, even at the eight-unit stage. It has been used to extrapolate that a thousand or so moves are needed to win in the record eight-piece position (and many thousands of moves for nine and ten pieces). This exponential growth pattern вЂ“ the number of moves roughly doubles for each piece added вЂ“ has been dubbed HaworthвЂ™s Law. It was observed that as the number of pieces increases in these record positions, the length of the perfect-play solution extends dramatically. Now he reveals which portions of the eight-piece tablebases have been completed and presents some of the most interesting positions found.ДЄs tablebases advanced in solving more complex endgames, researchers were able to determine the longest possible forced win in positions with a total of three to seven units. Marc was the co-discoverer of the famous seven-piece position in which it takes White over 500 moves to force a win.

#Stockfish endgame tablebase update#

One such developer, Marc Bourzutschky, has written a fascinating article-length update on the progress of his work, published on the Dutch endgame-study site, ARVES. In the years since the releases of these databases, programmers have been building on the eight-piece version, which of course requires tremendous computer resources. As discussed in that blog series, the two most comprehensive tablebases currently are the Lomonosov and Syzygy, both of which cover all possible endgames with up to seven pieces. If youвЂ™re new to the subject, though, refer to my introductory Adventures with endgame tablebases.

#Stockfish endgame tablebase software#

Many readers will be familiar with tablebases, software that effectively plays perfect chess in certain endgame positions.