OCTAGON

For a time, my great-uncle held the record for the most bicycles balanced on his head (5) and the longest distance walked with a bike balanced on his head (600 metres). He worked as a magician, travelled with a circus for a while, painted houses and worked in a bottling factory. He also invented board games in the 80s. Once in a while, we go to his place and try a few. The one that I liked the most was the simplest one, called Octagon. I wondered whether there is a forced win for the first player, or the second player, or whether no side can force a win. I implemented the game rules myself, plus a little interface to play against a fairly basic game engine. After the advent of generative AI, I had it try solving the game. It determined that, from the starting position, the first player has, in fact, a forced win in 45 moves, or 89 half-moves. I find it astonishing that the first-player advantage is significant enough to yield a forced win (I'd have expected an unwinnable game for both sides), but slight enough to yield it only after such a long sequence of moves.