Extra example:
Consider the following extremely silly game, which I’ll call “first to claim the centre”.
- The game is played on a 99x99 board
- The players alternate between placing a stone on an empty intersection
- There’s no capturing mechanics, once a stone is placed it will remain there for the rest of the game.
- The game ends as soon as a stone is placed in the centre (tengen) intersection.
- After the game ends, the player wins who had the last turn (thus the first player who puts a stone on the centre intersection wins the game)
Now, it’s pretty easy to see that there are 99×99 -1 = 9800 intersections on the board that don’t matter. But, the players can alternatingly place stones on any of these intersections before either player attempts to place a stone in the centre, and thus there are already 9800 × 9799 × 9798 × … × 3 × 2 × 1 = 9800! (factorial) possible sequences in which the players could fill the entire board except the centre. That’s around 1034861 possible sequences. Hence the game complexity is far larger than that of Go.
Meanwhile, solving the game is easy: the first player just places their stone in the centre for their first move, and wins the game. Done.