Some main events in the history of creating chess endgame table bases: Now their EGTBs are available online (for some payment) and it is possible to verify online any 7–man position (except 6 pieces versus lonely king). In 2012 the team from the Moscow State University (Vladimir Makhnychev and Victor Zakharov) constructed 7–man EGTBs using the supercomputer Lomonosov in the DTM format. In fact, 2 studies by computer were already published and according to experts in chess composition (Oleg Pervakov and others) they are good enough. Thus the computer acts in a role of the composer of chess studies, the man needs only to analyze the found positions and to decide, whether is they ready studies or not, at desire it is possible to add additional moves. This approach was suggested by well known mathematician and chess composer Noam Elkies and was implemented by Marc and Yakov. The second result is the usage of the idea about the limited promotions for finding of positions in which two or even three under promotions into different pieces are necessary for a win. It has appeared that generally four bishops win, and it is necessary more than 50 moves for a win. The most interesting of them is the base "four bishops against two rooks". The first of them – construction of several eight–piece bases without pawns in which one of the sides has two dark–squared and two light–squared bishops. There are two interesting results achieved by Marc Bourzutschky and Yakov Konoval already in 2009. Karsten Müller thinks that for a human over the board play the 50 move shall remain as human play is not perfect anyway. More than 500 moves can be played ( Figure 3).įigure 3 More than 500 moves can be played. In a chess composition this rule it is not taken at all into consideration, besides it is easy to find positions where this rule is taken in account, but in absolutely drawn positions it is possible to play more than 500 moves.
In this situation the rule of 50 moves, in Yakov Konoval's opinion, demands specification, differently it breaks logic of chess struggle.
#ENDGAME TABLEBASE SOLVED FOR FULL#
Even in pawn full endings there are many positions where a huge number of moves are needed for win.
In general in many pawn less endings more than 50 moves before conversion are necessary for a win, and it was already known and for a number of six–pieced and even the five–pieced endings, even such ending, as "a queen and a rook against a queen". Black to move and white wins in 517 moves ( Figure 1). In May 2006 the position with a win in 517 moves has been found in the ending a queen and a knight against a rook, a bishop and a knight. Further variety of records has been found still. A win in 290 moves in the ending "two rooks and a knight against two rooks" became the first of them. It has appeared that in the seven–piece endings there are longer wins. Later it has been established that the record to mate in this class of the endings makes 262 moves. Before the construction of seven–piece bases the longest known win in the endings was a win in 243 moves (before conversion) in the ending "a rook and a knight against two knights", found by Lewis Stiller in 1991.