Chess Online

Quite a bit of work going through and verifying the variations. But when you do , you will observe that every pawn has a specific purpose.
There are some (but not all) elegant model mates as well.

[Hat on]
You would think that a mate is a mate is a mate.
Not so in the world of chess problems: 'Mates are not created equal.'

* A mate involving all white officers (king excepted) is called an economical mate.

* A mate, where each square around the king is taken only in one way is called a pure mate.
Each such square is either controlled by one of the opponent's men or blocked by an own man.
If a blocking piece is pinned and without pin there is no mate, then the mate is still
considered pure and the pinning piece is involved in such mate.

* A mate that is pure and economical is known as a model mate.
* A model mate involving all men in the board (white and black) is called an ideal mate.
[Hat off]

A very hard and very satisfying puzzle (problem,..., whatever). Thanks, abdalmoneem.

Thank you too, donnaclara.

Practice, my friend. That's all. Have a nice day.