> A combinatorial game is two-player terminating game with perfect information. In other words, two players (called Left and Right) alternate changing some game state, which they always have full knowledge of. The game cannot go on forever, and whoever is left without a move to make loses. There are no draws.

> Non-examples include [...] Chess, which can end in a tie

And yet, somehow, tic-tac-toe is considered a combinatorial game. Not only can it end in a tie, it always will unless one player is very new to the game.

If we're willing to count tic-tac-toe by defining some tie states as victories for one side, why can't we do the same thing with chess?