I was having a mini-training session with Fritz (set to a much much lower performance setting naturally). It's been a very very tough fight to bring home the point.
And we arrived at the following interesting position (see inset). White has a slight advantage in the position.
I am White and it is White's turn to move.
Let us evaluate this:
What are Black's threats?
Black threatens to liberate his Knight's position with 1... Nb6 (putting pressure on the d5 pawn) or 1.. Nc5/Nf6 (forming a double battery and also putting pressure on the d5 pawn) afterwhich, Black threatens to take the h2-pawn with 2... Qxh2.
The question is: How can White stop this and yet maintain the advantage?
The answer can be found by highlighting between the brackets
[White has the brilliant resource 1. Bd4!! which stops this nonsense. Now the Black Knight is pinned to its position because if 1... Nf6 2. Qa7# and 1.... Nc5 or Nb6 2. Be5 wins the Queen]