Chess is full of king and pawn endings like the one above.
Often, there are more pawns on the board, but the winning
technique is the same. When there are only kings and pawns
left on the board, the position of the kings in relationship
to each other is very important. This is called the Opposition.
In the position above, White's plan is simple and clear.
White must queen the passed pawn to win. White has two
options : a) move the king b) advance the pawn.
The choice spells the difference between a win or a draw.
What would you do?
Advancing the pawn is consistent with the plan. It brings
the pawn closer to its queening square, but is it the right
move?
1 e6 Ke7
2 Ke5 Ke8
3 Kd6 Kd8
4 e7 Ke8
Draw
Not 3 ... Kf8? 4 Kd7 Kg7 5 e7 and White wins.
Now, let's try the other option.
1 Ke6 ...
White takes the direct Opposition to the black king.
1 ... Kd8
The Rule :
The King must preceed the pawn to the 6th rank in order
Black must give way with his next move.
2 Kf7 Kd7
3 e6 Kd8
4 e7 Kd7
5 e8 (Q) and wins
white king, by going ahead of the pawn and by using the
Opposition, was able to drive away the opposing king.
The passed pawn could not do the same
for the pawn to queen. If the pawn preceeds the king to
the 6th rank, it is a draw.