3.11. Complex Knight Endings
Among the complex knight endings of the greatest interest are those with four against three pawns. Most often these positions are won since pawns have passed the “critical mass” so salvation by a reduction of material is not possible. The simplest cases involve an outside passed pawn. The stronger side wins easily by advancing the passed pawn and deflecting the enemy pieces. Some problems may appear only when the king has been cut off and cannot support its passed pawn or when the isolated passed pawn is not far away from the other pawns so the knight can quickly switch from the defence on one wing to the other. An unusual case which aptly demonstrates the great strength of the outside passed pawn is illustrated by the ending of the game Ivkov – Filip ,Vrsac, 1971.