Complex sentence: In this game between two grandmasters, both players made suboptimal moves, but the superior side had no idea how to win and ended up stalemating several moves after the inferior side could have claimed a draw under the fifty-move rule.
Split into simpler sentences: In this game between two grandmasters, both players made suboptimal moves. The superior side had no idea how to win and ended up stalemating several moves after the inferior side could have claimed a draw under the fifty-move rule.