I don't think so.
Because, the longest chess game ever played was 269 moves and end in a draw.
Although they spent 20 Hours playing.
https://www.google.com/search?q=What+is+the+longest+chess+game+ever&rlz=1C1CHBF_en-GBLK1098LK1098&oq=What+is+the+longest+chess+game+ever&gs_lcrp=EgZjaHJvbWUyBggAEEUYOTIGCAEQRRg70gEINzcyNGowajeoAgCwAgA&sourceid=chrome&ie=UTF-8
I really enjoyed reading this and I lost it at:
"I inserted this picture for the sole purpose of making this article look less text-heavy." :D
It will take me a while to read this through. but I approve of the substracting (in part method) reasoning from a large set that we know to characterize and then making bound arguments under and upper.. I did not expect thought that one could reach the exact depth of a known position and its path. so I will study this. with pen and paper so I can reason it myself. perhaps I can find some virtual pen and paper, but I have not found the digital equivalent.. or an Ipad with pencil is too expensive and not 2D expandable like a bunch of sheets i could fight trhough.
good approach..
@Tobs40 said in #3:
> @Sid_907 A chess game can have thousands of moves, but a reachable position can have at most 218 moves.
I do not understand that statement. can you elaborate the difference betwee a game, and a reachable position
is this about fold repeats and reachable would exclude those along the way?
@Garry_Springsteen said in #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.
@tromp1234 said in #7:
> That's a large overestimate.
>
> github.com/tromp/ChessPositionRanking accurately estimates the number of legal chess positions at ~4.8*10^44.
Oh, good to know, I'll fix that, thanks :)
Reachable legal positions before an exchange can all be limited by the 50 move rule. Move 2 (Black's first reply) is the absolute earliest a capture can occur, and by writing a script to exclude all captures or promotions, you would be pruning the game tree, making the space of possibilities smaller.
This would permit to count how many legal moves there are without captures or pawn promotions. It's not a perft command but maybe a mix with it would help to determine at least the reality of that before exchanges and promotions.
@dboing said in #14:
> I do not understand that statement. can you elaborate the difference betwee a game, and a reachable position
> is this about fold repeats and reachable would exclude those along the way?
A chess game can (theoretically), if people intentionally make repetitive moves, within the FIDE rules, go on for thousands of moves. E.g. people at tournaments need a loooot of sheets to write down their moves :)
In practice, according to this forum, the longest game lasted 269 moves.
My article considered the number of legal moves available in a given position e.g. the number of moves a player can choose from for their next move.
A position is reachable, if there is a sequence of legal moves leading to it from the starting position. The distinction between reachable and non-reachable positions is interesting, because you could think of non-reachable positions as "not actually part of chess".
@dboing said in #13:
> It will take me a while to read this through. but I approve of the substracting (in part method) reasoning from a large set that we know to characterize and then making bound arguments under and upper.. I did not expect thought that one could reach the exact depth of a known position and its path. so I will study this. with pen and paper so I can reason it myself. perhaps I can find some virtual pen and paper, but I have not found the digital equivalent.. or an Ipad with pencil is too expensive and not 2D expandable like a bunch of sheets i could fight trhough.
>
> good approach..
Haha, reasoning about how to get to a position is a waaay harder problem and my approach would be horrible for that. My article is about the number of moves to choose from for the next move you play.
Thanks for the compliments though ^
@Garry_Springsteen said in #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.
Yes, I'm so sorry, I did not anticipate this misunderstanding .___. I'll change the title of course!
it's interesting to try use worstfish to calculate, because he wants a game to be lost by him, so game lasts longer in that way