2.3.3. Passed Pawns
When each side has passed pawns, of utmost importance is their relative proximity to the promotion square, that is to say, how fast they can queen. If the king of the weaker side has managed in time to occupy the critical squares in front of the enemy pawn, the game will be generally drawn. Otherwise the speed of the pawns will decide. However, it is possible to alter to a great degree the speed of the pawns by either getting the king inside the pawns’ square or guiding the enemy king to an unfavourable square in order to promote with check. Sometimes this can also be achieved by limiting the activity of the enemy king. Let us first consider the simplest case examined by I. Moravec in a study published in 1952. Since the black pawn is still on its initial position, the “square” comprises the sixth rank and the c-file. Although White to move cannot get into the square directly, the position is nevertheless drawn due to the fact that the black king does not control the critical square b7. The solution consists in moving the king diagonally; the white king will simultaneously approach both the pawn’s square and the critical square b7!