The Chess Board

[MorningLightMountain]

some of the longest known checkmates in chess:

http://kirill-kryukov.com/chess/longest-checkmates/longest-checkmates.shtml

(note: some of these might ignore the 50 move rule, which could make them a draw in an official game if one of the opponents decides to claim it)

also of interest is that discoveries made by computer chess endgame tablebases (EGTBs) once caused this rule to be changed when it was found that there were many forced checkmates possible that were longer than 50 moves...later, the rule was reinstated back to 50 moves, since us humble humans have a hard time playing perfectly for a grinding hundred or more moves!!!

http://en.wikipedia.org/wiki/Fifty-move_rule

The fifty-move rule in chess states that a player can claim a draw if no capture has been made and no pawn has been moved in the last fifty consecutive moves (fifty moves by each side)

In the 20th century it was discovered that some positions of certain endgames can only be won in more than fifty moves (without a capture or a pawn move). The rule was changed to include certain exceptions in which one hundred moves were allowed with particular material combinations. However, more and more exceptions were discovered and in 1992 FIDE abolished all such exceptions and reinstated the strict fifty-move rule.

below are some long mates of interest, with the FEN string following, which can be input in the link below....for example, in the 1st example, copy and past the info after the 211 (which is the maximum moves until a forced move with perfect play) using the "Input Fen" button in the below link to see it for yourself!!!

http://www.shredderchess.com/online-chess/online-databases/endgame-database.html/


KRPPKP 211 8/k1P5/8/8/1R5P/8/7p/3K4 w - - 0 1

KRPPKQ 216 8/k1P5/8/8/1R5P/8/K7/7q w - - 0 1

KRRPKP 218 8/7k/8/8/PR3R2/8/p7/3K4 w - - 0 1

KRRPKQ 253 q7/7k/8/6R1/8/8/2P2R2/K7 w - - 0 1

KRPKBN 204 8/1P6/8/n7/2K5/1b1R4/8/6k1 w - - 0 1

KRNKNN 262 6k1/5n2/8/8/8/5n2/1RK5/1N6 w - - 0 1

(WOW, a FORCED mate in 262 moves!!!)