Consider the following position with white to move. What is the best move?
White has an overwhelming advantage. In fact, the position is a win for white.
Based on Parts 1 and 2, we don’t really need any additional rules to determine the best sequence of moves. The best sequence is 1. Rd3 Kh1 2. Rh3#
However, in the process of decision-making in chess, it’s also important to have rules that allow us to rule out certain moves in addition to having rules that allow us to select moves.
We note above that Ke1, Ke2, Ke3, and Kf1 result in a position that is drawn.
Based on this, we formulate the following rule:
1.3 If the position is won, then don’t make a move that results in a drawn or lost position. If the position is drawn, then don’t make a move that results in a lost position.
Should we be uncertain about the best move in the above position, we at least have a rule that allows us to rule out several moves that change the outcome of the position.