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There is no reachable chess position with more than 218 moves.

#2

Yes, that is true. No chess games can be played for more than 218 moves. Unreachable chess positions include the side having to move able to capture the opposing king, every side having multiple kings, pawns on the 1st or 8th rank, two bishops on the same color, and both kings in check at the same time.

Yes, that is true. No chess games can be played for more than 218 moves. Unreachable chess positions include the side having to move able to capture the opposing king, every side having multiple kings, pawns on the 1st or 8th rank, two bishops on the same color, and both kings in check at the same time.
#3

@Sid_907 A chess game can have thousands of moves, but a reachable position can have at most 218 moves.

@Sid_907 A chess game can have thousands of moves, but a reachable position can have at most 218 moves.
#5

This is so cool! I love to see linear programming in action; it really feels like magic to me. Thanks for taking the time to show us your thought process and putting in the effort of actually coding it all up :D

This is so cool! I love to see linear programming in action; it really feels like magic to me. Thanks for taking the time to show us your thought process and putting in the effort of actually coding it all up :D
#6

@Tobs40 said in #1:

Comments on lichess.org/@/tobs40/blog/there-is-no-reachable-chess-position-with-more-than-218-moves/a5xdxeqs
Great blog! The fact: The game between Ivan Nikolic and Goran Arsovic, played in Belgrade in 1989, is considered the longest chess game in history. It lasted 20 hours and 15 minutes and ended in a draw after 269 moves.

@Tobs40 said in #1: > Comments on lichess.org/@/tobs40/blog/there-is-no-reachable-chess-position-with-more-than-218-moves/a5xdxeqs Great blog! The fact: The game between Ivan Nikolic and Goran Arsovic, played in Belgrade in 1989, is considered the longest chess game in history. It lasted 20 hours and 15 minutes and ended in a draw after 269 moves.
#7

By checking all approximately 8.7x10^45 reachable chess positions?

That's a large overestimate.

https://github.com/tromp/ChessPositionRanking accurately estimates the number of legal chess positions at ~4.8*10^44.

> By checking all approximately 8.7x10^45 reachable chess positions? That's a large overestimate. https://github.com/tromp/ChessPositionRanking accurately estimates the number of legal chess positions at ~4.8*10^44.
#8

"218 is the maximum number of possible moves in a legal position" would have been a better title. As some people seem to be confused and think you're stating that every legal position can be reached in at most 218 moves.

"218 is the maximum number of possible moves in a legal position" would have been a better title. As some people seem to be confused and think you're stating that every legal position can be reached in at most 218 moves.
#9

While the result seems true, I don't really understand the value of it.

While the result seems true, I don't really understand the value of it.
#10

tre
but who will anyone even reach till move 200

tre but who will anyone even reach till move 200