4 ms·
Given the current upper bound on legal chess positions is 7.7e45 ≈ 152.4 bits, you either have found a better upper bound or your memory doesn't serve.
by eulgro 9mo ago
Given the current upper bound on legal chess positions is 7.7e45 ≈ 152.4 bits, you either have found a better upper bound or your memory doesn't serve.
- wongarsu 9mo agoThey didn't try to encode all legal positions though, only ones that were actually reached in their database of games. It sounds very plausible to me that this allows a lot of simplifying assumptions that cut the state space by about 60 bits
- mlyle 9mo agoI can put it all in, say, 24 bits, if my database is small. 140k games, 120 positions each. log(140000*120)/log(2) ~~ 24.001, and surely there will be some duplication. The encoding is just the index number of the game + move that resulted in that position.
- pklausler 9mo agoThe duplication is the problem if you want to use positions as DB keys.
- bombcar 9mo agoNow I'm wondering if it is a "legal" chess position to get the pieces to swap sides ... a solver to find how to do it would be amusing.
- NitpickLawyer 9mo agoNot what you asked for, sorry, but it reminded me of this gem - https://www.youtube.com/watch?v=C5JVFCouXIU https://www.youtube.com/watch?v=C5JVFCouXIU
- mlyle 9mo agoObviously not possible -- how would pawns pass each other without captures?
- bombcar 9mo agoAh! True, I worked out how you could have OTHER pieces get around a pawn, but pawns themselves can't get past each other.