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0 pointskelipso9mo ago0 comments

Is that weird? I feel like it’s plausible though. Very rare to have chess games with more than 200 moves.

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8 comments · 2 top-level

refulgentis9mo ago· 5 in thread

It’s also rare to have one with more than 50 moves. I’m curious if this class of observation will help establish a true bounds. Especially because we don’t have a definition of what it means - my instinct is to first do that, so “infinity” isn’t the obvious upper bound.

kelipsoOP9mo ago

Proving this feels more difficult than proving what’s in the OP article, because here you have to show path lengths between original position and all possible positions have a max length, while OP article had to show all positions have a max degree. Path length just seems like a harder problem compared to node degree.

LorenPechtel9mo ago

The upper bound is a few thousand. A game is considered drawn if no pawn has moved and no piece has been captured for 50 moves. And there's also the threefold repetition rule: if the same exact position (counting things like castling eligibility etc) occurs three times it's drawn.

chipsrafferty8mo ago

I think the upper bound is 6300, then. Each pawn can move 6 times, times 16 pawns, times 50 moves before a game ending draw, plus each capturable piece that can delay the game another 50 moves (15 on each side)

tln9mo ago

What? Lots of serious chess games last more than 50 moves

Not sure if I'm reading your comment correctly

The upper bound of moves is 8848.5 https://www.reddit.com/r/chess/comments/168qmk6/longest_poss...

... under the rule that after 75 moves without a capture or pawn advancement the game is drawn

refulgentis9mo ago

You read a comment saying it’s rare to have more than 200 moves, then a reply noting more than 50 is also rare, then suggested you were confused and maybe it was unreadable and asked “What?” because…some games have above 50 moves. shrugs

Thanks for note re: upper bound with 75 moves without pawn advancing constraint.

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stavros9mo ago· 1 in thread

Yeah I kind of thought that it meant "you can get to any valid position in 218 moves max", it was hard to parse.

OwlGoesHoot9mo ago

I read it as “there is no legal position for which the minimum number of moves necessary to reach it is greater than 218” but I also did not read the whole article before coming to check the comments

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