Instructive positions

After Qd2 white is ready to play Bh6
and it seems like Re8 is the correct
move here, because of the possibility
to answer Bh6 with Bh8, but even
better is Ne4, a move that wins a pawn
for black; either with Nxe4, dxe4, Ng1,
Qxd4 or Qc1/Qe3, Nxg5, Nxg5, dxc4,
e3, Be6 When white have Bg5 and Qd2
you must calculate on Ne4, if possible.
 
White have played h3, but black don't need to move the bishop, because of the pin. If Qb6, Qd4 or c5 and white plays hxg4, then he lose the game, because of Rxh1+ fol-lowed by Rxa1 You must calculate whether a threatened piece have to move or not.
In this position white can move on with the c-pawn because if Rxb6, then c7, and the rook can't stop the pawn from queening. If black plays Rc6, then Rh6+ followed by Rxc6 and black can resign.
     
     


White to move can win this position, because the pawn needs help from the king: