My thought was to have additional schemes depending on the length of the byte array. For example, if the position is an empty array it is the beginning position

My thought was to have additional schemes depending on the length of the byte array. For example, if the position is an empty array it is the beginning position, if it is 1 byte it represents the most common positions. "" is the beginning position "0" is E4 "1" is D4 "2" is C4 "3" is E4 E5 "4" is D4 D5 "5" is G3 One could do a multi byte version where the order of popular positions is replaced with a crappy chess computer. If there is no en-passant, no promoted pawn and castling is allowed you can use representations slightly shorter than 24.