This is just completely backwards. Full ring limit is much easier to play optimally than heads up. A bot could break even with a good starting hand list and bas

This is just completely backwards. Full ring limit is much easier to play optimally than heads up. A bot could break even with a good starting hand list and basic actions. Heads up play involves many many situations where the optimal plays are highly non-intuitive and involve both exploiting patterns in your opponents play and "advertising" for the future. This is because both players /usually/ have weak hands. Heads up limit poker requires a very strong understanding of game theory, not just "poker theory". Combine that with the fact that if you have an exploitable leak, it will get exploited over and over again. Heads up limit poker was /quite/ popular before the US cracked down and online gaming and many players made a ton of money off it. Towards the end, it was clear botters were getting in on the action, and bots were already playing an extremely difficult game. You are correct that no-limit, especially heads-up no-limit remains a tougher nut to crack from an AI perspective, but this is pretty damn impressive NB: I played online poker professionally for a few years.