A light group is not a weak group? Understanding attack and defense in the context of the Clossi approach to move selection

At move 18 in a game I just lost, I am faced with this board position:

Now, using the Clossi approach, I have to ask the first question: am I weak? and this is a very key point: the H3 stone is “light” but is it “weak”? If it is weak, we have 4 prioritized options:

  1. make a base
  2. run away
  3. make eye space
  4. play my vital point

I might be able to make a base by playing F3 (contacting an already strong group) but K3 is out of the question. So we move to “run away” … and J4 (what I played) represents running away and also breaking the sector line formed between the E4 and L3 stones.

But before we consider options to question 1, we MUST be certain of what is weak versus what is light. And if H3 is only light then not weak, then we MUST continue to questions 2 and 3.

But AI likes building the left side?

AI evaluates the board position like so:

Again strictly adhering to the Clossi approach, this appears to be a move based on the third option in the clossi approach – “make a big move” which is chosen after the answer is “no” to the questions (1) am I weak and (2) is my opponent weak. My D4 group is abysmal and it goes back to my sub-standard handling of White playing C3… the group is cramped and eventually dies. But H3 is considerably weaker unless you consider it light… not weak.

Equal sharing is an unstated Clossi approach principle.

On Clossius’ Twitch channel, he often states something to the effect of: “the goal in any series of moves is balanced sharing”… with this in mind we can see that Black could be saying “Go ahead and munch the H3 stone… the left side that I build will be equal or greater to what you get for munching up that light stone”

“Attack from the weak side” is a classic go principle.

I did not hesitate much before playing H4 because I was certain I should attack from the threatened/weak side. It also falls in line with Bruce Wilcox‘s suggestion to break the sector line formed by your opponent in a sector fight.

In the Clossi approach you always “attack from the weak side” because question 1 in the Clossi approach is “am I weak” and as your rating improves, you learned to run-away while creating threats.

Feedback is requested

  1. Is H3 weak or light?
  2. why should one choose O3 or H4?
  3. any comments on move selection algorithms in Go such as The Clossi Approach or The ROSE method?

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