The art of the chess problem is rich and long. Some are simple; others are extremely difficult to solve. The simple ones can be mind boggling to the novice. Such is the following position: White Ph2 B/e4 and g1, Qh4/Kh1. Black Kg7 / Bb7 / Qa3.
Chess problems usually find the squares to be the key to chess strategy which often feature the lack of mobility for the king. If you had been privileged to view the Carlsen final Q-sac brilliancy, the actual condition was easy to arrive at. Just using square count and viewing the W/Q squares it attacked, would show easily the crushing move that was so appealing to the audience. Often, it is the seemingly “impossible” that turns the screws in the position leading to checkmate. The key as I said to checkmate was the elimination of squares for the king to escape checks.
The above sample position shows Black to move and force checkmate. The Queen guards the Bishop on e4. So the question is: How does the mate occur? Or, does it? The answer is that the improbable becomes the possible and fulfilled in the actual moves to play. 1…Qa3-f3 check. This forces 2. B:Q and it is the black B:f3 checkmate.
A cute finish comes in the diagram: White Ph2, d3, Bc4, Rg2, Qf1, Kh1. Black Kh8 /Ra8 / Bb7 / Qc6. Things don’t look so hot for White’s King on h1. Black to move wins easily. But supposing it is White to move? 1. Bd5! looks rather startling.
It is easy to ask the computer to solve a problem or any game position to choose a course of action. But the chess player loses the battle because the human brain is not challenged. That is the key reason to use your own computer–your brain not some electronic device!