Oh, it's Reversi! https://en.wikipedia.org/wiki/Reversi https://en.wikipedia.org/wiki/Reversi By the way - in the general case (NxN board, arbitrary position)

Oh, it's Reversi! https://en.wikipedia.org/wiki/Reversi https://en.wikipedia.org/wiki/Reversi By the way - in the general case (NxN board, arbitrary position) - determining whether there's a winning strategy is a PSPACE-complete problem.