Hi Yogi,

If I have understood your point of view correctly, you are looking for simplicity and efficiency in resolution.

I suggest that you take an interest in the

TDP (track's technique) which allows you to solve without having to know all the expert techniques (wing, fish, ALS, etc...).

To put it simply, you build two chains P(A) and P(B) from a pair of strongly linked candidates A and B, and you look for the candidates common to these two chains, they are solutions.

P(A) is constructed by assuming (hypothesis) that A is the solution and using basic techniques to place the other candidates resulting from this hypothesis. Ditto for P(B).

Here is an example of how to solve the puzzle you are proposing, which I think is rather easy.

A=9r1c5 => P(A) = {9r1c5, 9r5c6, 9r6c2, 9r9c9, 9r7c3,

8r3c3, ...}

B=9r3c6 => P(B) = {9r3c6,

8r3c3, ... }

=> r3c3=8 and the puzzle ends with the basic techniques.

P(A) is marked in blue, P(B) is marked in yellow.

You can also reason with a single anti-track P'(B) obtained by assuming that B is eliminated, this gives :

P'(9r3c6) = {9r1c5, 9r5c6, 9r6c2, 9r9c9, 9r7c3, ...} which eliminates any candidate who sees the starting candidate B=9r3c6 and the finishing candidate 9r7c3, here the 9r3c3.

I published on this forum a theoretical document on TDP that suggests that the technique is complicated. In practice it is very easy to apply.

I give on this forum examples of resolution with TDP.

Robert