It is obvious that the winning prospects are much slimmer in endings with no passed pawns. The crucial factor here is king activity. The win depends on whether a breakthrough to the rear of the enemy pawn is possible or if by the advance of the “potential” passed pawn at the right moment a transition to some of the elementary king and one pawn versus king ending can be reached provided the white king can secure one of the critical squares in front of the passed pawn. Taking into consideration the pawn structure and the problems involving converting advantage into victory, we may distinguish two basic types: with blockaded pawns with mobile pawn structure. In positions with blockaded pawns White has no reserve pawn moves. Therefore, the outcome will depend on better king position or the opposition. A typical, self-explanatory case is shown in the following diagram. This is a position of mutual zugzwang. White to move draws; Black to move loses! Black to move loses since he must give up the opposition. As a consequence, the black pawn will either fall by force or the white pawn will promote into the queen.