[sfeng]

I would love to see this benchmarked against just running LZW compression on a list of the moves. I think the repeated nature of the moves means the entropy is actually rather low. It should be possible to come up with a compression dictionary which can save a lot more space than just a tight packing like this.

[vardump]

LZW would do very badly on a list of binary chess moves.

Huffman (and even more so arithmetic encoding or ANS (asymmetric numeral systems [0]) would be significantly better, if you're careful how you encode data.

[0]: https://en.wikipedia.org/wiki/Asymmetric_numeral_systems

[kondro]

Or a trained zstd dictionary.

[sedatk]

> the repeated nature of the moves

On a single game? I don’t think the goal is to pack all plays together and unpack them every time. Every game must be individually accessible as I understand.