Some games were designed to be difficult for computers, primarily by having a large branching factor. Aarimaa [1] seems to be holding up so far. Octi [2] is

Some games were designed to be difficult for computers, primarily by having a large branching factor. Aarimaa [1] seems to be holding up so far. Octi [2] is perhaps too obscure to get much attention and Havannah [3] has been defeated in the years since the author invited computer challengers to try. [1] https://en.wikipedia.org/wiki/Arimaa#World_Computer_Championship https://en.wikipedia.org/wiki/Arimaa#World_Computer_Champion... [2] https://boardgamegeek.com/boardgame/450/octi https://boardgamegeek.com/boardgame/450/octi [3] https://en.wikipedia.org/wiki/Havannah#Computer_Havannah https://en.wikipedia.org/wiki/Havannah#Computer_Havannah