## Monday, April 04, 2016

### Examples 2,3: prelimanary moves

The fact that my five step thought process covers all possibilities to gain wood in a forced way, makes that I sometimes can make progress by exclusion. If four of the five steps are excluded, the gain of wood must come from the remaining step. Since 3 of the 5 steps have geometrical characteristics which usually are easy to spot, a lot of time can be saved.

Sometimes the solution is obscured by preliminary moves. There are two main types: moves that put the targets into place and moves that put the attackers into place. The moves have in common that the initiative must be preserved, so it are CCT moves.

 Example 2 Black to move and win
8/5k2/3Rn3/1p3r2/1P5P/2N2RK1/8/4r3 b - - 1 1
solution

The winning motif is not visible yet. The targets are not in place.
1. ... Rg1+ preliminary move 1 forces the white king into a skewer
2.Kf2 Rf1+ preliminary move 2 attracts the white king in a double attack
3.Kxf1 Rxf3+ executes the winning double attack.

The double attack is not visible in the start position. So trial & error seems to be the only option.

Another example:

 Example 3 Black to play and win
q3k1r1/2R2p1p/3Qp3/3b1p2/Pp1P4/5n2/1P3PPP/R4K2 b - - 1 1
Solution

The winning motif is not visible yet. The targets are not in place.
1. ... Bc4+ preliminary move which attracts the rook into place
2.Rxc4 Nd2+ executes the double attack.

When the targets are not in place, the duplo attacks are obscured. Can preliminary moves only be found by trial and error?

1. I am not sure if you know what I mean, but the second example (diagram) is much simpler that the first one. Why is that?

Compare the Kings at BOTH of the diagrams:

1) White King has 5 moves
2) White King has just 1 move

I can understand and comprehend FULL position due to the King's restriction. And if you look closely the two squares (f1+e2) creates a diagonal. That's why finding Bc4+ is a way easier than "usual".

And what about puzzle 1? It is quite hard to me to see the solution as there no visible motifs to exploit. Ok, we have Rd6 not protected, but what else? I bet most weaker players would not solve this puzzle below 2-3 minutes. But the second puzzle may be solved easily within one minute.

I think one has to notice the possibility to create an X-ray motif: it is hardly visible (hidden well enough) to recognize it unless you solve the puzzle (or know the solution before).

Can any of you explain how to discover such hidden motifs at such puzzles? This one is really tricky as it contains deflection, removing of the guard and duplo attack (as the final shot).

1. That's the big question.
A gain of wood must always make use of at least one of my five steps. If none is found, there must be a preliminary move. There is no alternative. We already know that a preliminary move is an element of CCT, since the initiative must be preserved. Further I expect that the target of the preliminary move will have a relative high value, and that the move is so forcing that it leaves only one possibility. In the first diagram, white has not 5 logical moves for the king, as you suggest, but just 1.

2. This tells you something about the limitations of pattern recognition. Patterns that aren't there yet are difficult to recognize.

2. Question to native English speakers: do I use the word "preliminary" correct? In the the sense of "preparing (for the trap or duplo attack)?

1. Yes, you did. It is an excellent point.

3. In fact, all tactical motifs in a combination which are preliminary for the final trap or duplo attack are preparing the targets and the attackers into the right position. See the fist diagram. The skewer doesn't cash in the wood, it lures the king to its final place where it undergoes the final execution of the double attack. The skewer only preserves the initiative, while forcing the king in the right direction. So the preliminary tactical motifs have the same function as preliminary moves: to direct the targets and the attacker(s) into the position for the final blow.

I wonder if this means that we should focus on CCT moves with the least possible answers.

I hope you understand what I mean.

1. Many master suggest's something like this : Caclulate the most forcing lines first.

But i like to stay in the system of weakness-method. The problem of example 2 is that every piece is tactical weak, but: the weak king has to defend the weak rook which defend the not quite that weak knight. In a way the king is "pinned" to the rook, the standard method to make use of the "pin" is to attack the immobilised piece.

A system of interacting weaknesses is a weakness of higher order

4. The old habit of trial&error is strong, and hard to unlearn.

5. A rule of thumb when aknight can check see what other squares are impacted and look to force a decoy to that square.