Zugzwang

If all moves that a player can play weakens his position but this player has to play a move because it is his turn , it is called Zugzwang. The player has to make a move and he is obligated to play one of the bad moves .

   The situation of White is zugzwang. White cannot prevent to lose a piece. a3,a4 and b3 are temporary moves. Even if he plays these moves, he is forced to play one of the moves given below later .

1. Bc1 ? BxN
or 1. Re2? (or Rgf1? ) BxR
or 1.Rc1? Re2  2. Qxe2 Bxe2 white lost the queen
or 1. Bf1? BxB
or 1.g4 R(f5)f3 2. BxR Rh2 mate