he wins. On the other hand, the defender may be able to prevent the attacker from getting to such a position (see #Defending drawn positions). Recall that rule 1 above gives a condition which draws for Black. There are three cases to be considered. In any of these three cases, the white king is able to force his way onto a key square and thus reach a winning position. Accurate play from that position is still needed to win the game. Case 1, conditions (b) and (c) are met Conditions (b) and (c) are met in this diagram, if it is Black's move. Black cannot prevent the white king from reaching the key square d7. 1... Ke8 2. e7 Kf7 Black was in zugzwang. 3. Kd7 (a key square) followed by 4. e8=Q and White wins. This position illustrates an important rule of thumb: If the White king is on its sixth rank, the pawn must be advanced to the seventh rank without giving check. (If White's king is on the sixth rank and the pawn checks the Black king when it advances to the seventh rank, the black king can move in front of the pawn, resulting in a draw. In that case White has to either give up the pawn or move the king behind the pawn into stalemate.) Case 2, conditions (a) and (c) are met Conditions (a) and (c) are met in this diagram, with either side to move. If it is Black's move in this diagram, the game could go 1... Kg8 2. Kh6 Kh8 Black was in zugzwang. 3. g6 Kg8 4. g7 Kf7 5. Kh7 and White wins because the pawn advanced to the seventh rank without giving check, as in the position in the diagram in the previous section. If it is White's move in this diagram, 1. Kf7 (a key square) and Black cannot prevent the pawn from queening. White must take a little more care with a knight pawn. If White moves 1.Kf6, Black can reply 1...Kh7 and White must back up with 2.Kf7 Kh8 and proceed as above, because 2.g6+? Kh8! 3.Kf7 is stalemate. Case 3, conditions (a) and (b) are met Conditions (a) and (b) are met in this diagram, if Black is to move. The game could continue 1... Kd6 2. Kf5 Kd7 3. Kf6 Kd8 4. e4 Kd7 5. e5 Ke8 6. Ke6 White takes the