# How can one determine the chess configuration that maximizes the number of possible moves?

To clarify, what is the chess-board configuration that would maximize the number of valid moves one player could make on his or her turn? I thought of this question while playing chess, how apropos. I doubt there is a unique configuration, but I am not sure. The problem seems difficult because one must consider every single piece's movement, and the limitations on that piece's movement by other pieces. At any rate, I appreciate any thoughts, hints, or solutions.

• Is promoting to a knight considered a different move from promoting to a queen? Commented Mar 31, 2013 at 2:58
• I think it can't be unique, because you could swap the color of all pieces(and also which player will move next) to get a configuration with the same number of moves available. Commented Mar 31, 2013 at 2:59
• I agree, I think we could forget the uniqueness...but I would consider all promotion as one move (if you don't like that we can add those at the end) Commented Mar 31, 2013 at 3:03
• Curious question. But could you clarify what the conditions on the board are? Must the position be reachable in a legal chess game? Or can we just place pieces anywhere on an 8x8 board (e.g. 30 white queens and nothing else)? Commented Apr 3, 2013 at 17:20
• @DouglasS.Stones : I meant in accordance with the unfolding of a legal game on an 8x8 board, assuming no pieces get captured. However, I like your second variation as well (just placing pieces randomly on the board). Commented Apr 3, 2013 at 19:27