It is not very common that logic is used as the main source for moves. That may sound counter intuitive. But if you look around at club level, you will find lots of evidence that it is true. Take for instance the fact that everybody of adult age is plateauing for years, despite considerable efforts to get better.
Why is that? In the first place, chess is so overwhelmingly complex, that the mind is easily confused. And a confused mind cannot think logically. Secondly, chess players are addicted to variations. They cannot walk alongside a chess board without their mind going haywire. The main technique that is used is trial and error. Which is not based on logic. Furthermore, logical reasoning requires a bit more effort than trial and error. The mind is so wired, that it avoids the use of mental resources that require higher energy. It prefers to assign lower energy. Even if the price is a vast amount of lower energy.
Apparently, lower mental energy is cheaper than higher level mental energy. When system 1 must decide whether it should apply vast amounts of lower energy or a bit of higher energy, it prefers the first option. The reason for this, is that system 1 doesn't work with the concept frequency of occurrence. It simply assumes that the event is unique. And it is not going to spill long term resources to one-off events without good reason. Remember the story about the priest with the cheat sheet? System 1 isn't going to assign long term resources to learning a prayer by heart on its own account. You need system 2 for the decision to deliberately practice to learn the prayer by heart. And system 1 will follow when system 2 goes first. And that requires a higher level of conscious effort by system 2. And consciousness doesn't come cheap. Hence we shift to the automatic pilot.
Have a look at the following position.
|Mate in 3. Black to move|
2b4r/5k2/pQ3pp1/3R4/8/1P6/P3qBK1/3R4 b - - 1 1
It is not too difficult to solve this problem on autopilot, simply by trial and error. There are only a few candidate moves to consider. There are not much variations.
But if you do so, you don't learn anything from the position.
What is there what we possibly could want to learn from this position?
We want to abstrahere some chess logic from the position that is reusable for other positions. I mentioned already in the post of April 16th the grand scheme of mates. That scheme is of course pretty global, but that is exactly what I want to do: to refine it and make it more practical.
What is the most likely piece that is going to deliver mate? Usually it is the queen. So we must think how such mate might come about. Where is the mate going to be delivered by the queen? Usually on a square next to the king. Since the queen can only deliver mate next to the king when it is protected, the queen must be protected by the rook or the bishop. White is especially weak on the white squares, since he has no white squared bishop. His bishop can only defend by blocking the line of attack, not by protecting the white squares.
We must ask questions like:
Which squares are close to the white king which can be covered by a coöperation of two white pieces, like the queen and the rook or the queen and the bishop. In other words: which points of pressure can we bring about? Or as Vukovic would say it: what are the focal points. Since a focal point and a point of pressure next to the king is the same.
Potential point of pressure by Queen and rook: h1 and h3
Potential point of pressure by Queen and bishop: g2
Which leads to the following question: can we place the queen where it covers two potential points of pressure? In fact there is. 1. ... Qe4 covers both g2 and h1. It keeps the white bishop at bay and it comes with check (tempo). So white has no time for counterplay.
Wherever the king might flee to, the mate is soon going to be delivered by the queen from a point of pressure.
Can you see how even seemingly simple positions can help you to elaborate on your chess logic? Can you see how all chess logic is geared around the four areas of attention which are mentioned in the post of April 16th? Can you see how focusing on the points of pressure can transfer chess logic from one mate to another? How it makes chess logic reusable?
Of course you need a conscious effort for this. Deliberate practice, so to speak. It doesn't work on autopilot. Trial and error is useless. But it all starts with the insight that there is really something to learn that is reusable, even from seemingly simple positions.