@sk0bel Probably a combination of mathematical analysis and computation. However the tablebase generator really had to enumerate all the positions.
@BKIRCA But is is on the right side, isn't it?
@Shipustik Cheers, and more importantly thanks to Bojun Guo and Ronald de Man, who shared their work with everyone (including Lichess).
@Entuzijasta Full 8-piece set in 10 years does not look likely at this point, but I'd like to be proven wrong. RdM mentioned it might be feasible to generate a few well-chosen 8-piece tables to beat the record for the longest endgame.
@kettwiesel Pretty much exactly 5 months. I don't know more details about the hardware than given in the blog post. The compression really is excellent. Similar positions often have similar outcomes, especially if there is a material imbalance that gives one side a big advantage. Glad you like my Python library :)