Middlegame triangulation

Triangulation is a tactic used in chess to put one's opponent in zugzwang. That is, it gets to the same position with the other player to move, when it is a disadvantage for that player to move, he has to give up a blockade and let the other player penetrate his position. Triangulation is also called losing a tempo or losing a move. Triangulation occurs most commonly in endgames with only kings and pawns when one king can maneuver on three adjacent squares in the shape of a triangle and maintain the basic position while the opposing king only has two such squares. Thus, if one king triangulates by using three moves to return to the original square and the opposing king cannot do the same, he has lost a crucial tempo and reached the same position with the other player to move. Triangulation can occur in other endgames and even in some middlegames.