⚫Play Reversi

Reversi dates to 1883 and was rebranded in the 1970s under the name most people know it by today. It is the rare board game whose rules can be taught in thirty seconds and whose strategy runs directly against beginner intuition in almost every respect.

The central counter-intuition is disc count. Newcomers try to flip as many discs as possible on every turn, which is close to the worst thing you can do. Having lots of discs early means having lots of discs on the frontier — squares adjacent to empty space — and every frontier disc is a square your opponent can play next to. Strong players deliberately stay small and hand over the middle.

What actually matters is mobility and stability. Mobility is how many legal moves you have; running your opponent out of options forces them to hand you a corner eventually. Stability is discs that can never be flipped again, which radiates outward from the corners. The computer opponent here scores positions on both, weighting corners heavily and the squares diagonally beside them heavily negative.

The engine searches four moves ahead in the opening and midgame, then deepens to eight once fewer than ten squares remain, because the endgame is where the game is actually decided. It is beatable, but you will not beat it by grabbing discs.