You can get under one byte per move actually. There are less than 256 moves possible from any given chess position, so you just have an algorithm to order them,

You can get under one byte per move actually. There are less than 256 moves possible from any given chess position, so you just have an algorithm to order them, and index into that. You can do even better with variable length compression and move ordering. Here's a post from lichess about their system: https://lichess.org/blog/Wqa7GiAAAOIpBLoY/developer-update-275-improved-game-compression https://lichess.org/blog/Wqa7GiAAAOIpBLoY/developer-update-2...