Whether or not the white king can reach a key square depends on the position of the pieces.
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.
Black cannot prevent the white king from reaching the key square d7.
Kd1 the black rook must move and the white king goes back to e2.
Thus, the white king got stuck in the center after 14 Ke2.
Here, Black has the opposition, and is keeping the white king out.
The white king, for example, starts the game on square e1.
Therefore the white king had to come out of its corner at last.
In this example, f6 is also a key square for the white king.
A lone white king stands at the far end of the board.