|Sally Simpson: Hi Wilfredo,
Black has just played 43...Rd6-f7
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When asking yourself these questions always look to see what was played instead.
White did not take on d6 instead he played 44.Rb2 Why?
To stop Black turning his passive Rook into the best piece on the board by Rf6-f2, then from f2 we get Ra2 and the poorly placed Rook is now behind the passed pawn and hugging the 7th rank.
Look at the diagram again and imagine the Black Rook on a2 and Black plays Ra1.
Now suddenly mating threats are appearing with Black playing Ne2+.
White gets the d6 pawn but Black has all the play. The a-pawn will fall and due to that mate threat with Ra1 and Ne2+ White will most likely get zugzwanged into mate or have to give up the Rook for the Knight.
The d6 pawn was laced with poison.