I am interested in this joseki. I am always puzzled when it is better for white to play b directly and when a throw in at a first is the better option.

What is your opinion on this decision?

Click Here To Show Diagram Code

[go]$$W
$$ --------------------+
$$ . . . . . . . . . . |
$$ . . . . . . . O X . |
$$ . . . . . . O X . . |
$$ , . . . . . O X . . |
$$ . . . . . . O X a . |
$$ . . . . . . . O X . |
$$ . . . . . . . . b . |
$$ . . . . . . . . . . |
$$ . . . . . . . . . . |
$$ , . . . . . , . . . |[/go]

I am a bit relieved by the fact that the Bots are also puzzled by this question
(So probably the involved ladders a quite important.)

This is what ELF thinks:


This is what ELFv1 thinks:


This is what Superlizzie (Experimental Leela Zero) thinks:

Here are my thoughts...

Click Here To Show Diagram Code

[go]$$W
$$ --------------------+
$$ . . . . . . . . . . |
$$ . . . . . . . O X . |
$$ . . . . . . O X . . |
$$ , . . . . . O X . . |
$$ . . . . . . O X W . |
$$ . . . . . . C O X . |
$$ . . . . . . . . . . |
$$ . . . . . . . . . . |
$$ . . . . . . . . . . |
$$ , . . . . . , . . . |[/go]

Here, in many cases, I'd expect black to capture. He probably won't play the marked spot because of white's squeeze. So you might often expect this:

Click Here To Show Diagram Code

[go]$$W
$$ --------------------+
$$ . . . . . . . . . . |
$$ . . . . . . . O X . |
$$ . . . . . . O X . . |
$$ , . . . . . O X 2 . |
$$ . . . . . . O X . 4 |
$$ . . . . . . C O X . |
$$ . . . . . . . C 3 . |
$$ . . . . . . . . . . |
$$ . . . . . . . . . . |
$$ , . . . . . , . . . |[/go]

With some sort of defense in the marked area.

Now with the other one:

Click Here To Show Diagram Code

[go]$$W
$$ --------------------+
$$ . . . . . . . . . . |
$$ . . . . . . . O X . |
$$ . . . . . . O X . . |
$$ , . . . . . O X . . |
$$ . . . . . . O X . . |
$$ . . . . . . . O X . |
$$ . . . . . . . . W . |
$$ . . . . . . . . . . |
$$ . . . . . . . . . . |
$$ , . . . . . , . . . |[/go]

There is less pressure, so black can get a free atari in:

Click Here To Show Diagram Code

[go]$$B
$$ --------------------+
$$ . . . . . . . . . . |
$$ . . . . . . 3 O X . |
$$ . . . . . . O X . . |
$$ , . . . . . O X . . |
$$ . . . . . . O X C . |
$$ . . . . . . 1 O X . |
$$ . . . . . . . 2 O . |
$$ . . . . . . . . . . |
$$ . . . . . . . . . . |
$$ , . . . . . , . . . |[/go]

This leaves white with more defects on the outside, but I guess white can capture with the marked spot later.

So I guess it's a tradeoff between points and defects in the shape.

_________________
be immersed

I've seen the squeeze variation played/considered often by our new overlords

The squeeze allow black to get outside easily on the top side :

Click Here To Show Diagram Code

[go]$$B connect, black can atari at a before
$$ --------------------+
$$ . . . . . . . 3 . . |
$$ . . . . . . 1 O X . |
$$ . . . . 7 . O X 2 . |
$$ , . . . . . O X 4 . |
$$ . . . . . . O X W . |
$$ . . . . . . a O X . |
$$ . . . . . . . . 6 . |
$$ . . . . . . . . . . |
$$ . . . . . . . . . . |
$$ , . . . . . , . . . |[/go]

If white avoid squeezing to close the left side, it's not that great :

Click Here To Show Diagram Code

[go]$$B if W don't start the squeeze
$$ --------------------+
$$ . . . . . . . 3 . . |
$$ . . . . . 2 1 O X . |
$$ . . . . . . O X . . |
$$ , . . . . . O X . . |
$$ . . . . . . O X O . |
$$ . . . . . . a O X . |
$$ . . . . . . . b . . |
$$ . . . . . . . . . . |
$$ . . . . . . . . . . |
$$ , . . . . . , . . . |[/go]

Click Here To Show Diagram Code

[go]$$B if W stop in the middle of the squeeze
$$ --------------------+
$$ . . . . . . . 3 . . |
$$ . . . . . 4 1 O X . |
$$ . . . . . . O X 2 . |
$$ , . . . . . O X 5 . |
$$ . . . . . . O X O . |
$$ . . . . . . . O X . |
$$ . . . . . . . . . . |
$$ . . . . . . . . . . |
$$ . . . . . . . . . . |
$$ , . . . . . , . . . |[/go]

Who said 4-4 joseki were easy?

Thanks for your posts.

Ah, I start to see the light. I also checked my pro database games after reading your thoughts.

My mistake was to think of a as a mere throw in, but white aims for different variations with this move. Problem with a is in my opinion, it opens up more options for black to respond.

Now I would be really interested in a game where a is the only option and b is a bad play.

So I think now a aims for the squeeze, (but black does not have to give the squeeze.)

Ke Jie does not allow the squeeze in this one:

Kang Dongyun, 9p - Ke Jie, 9p, B+R (Komi 7.5)
12th Chunlan Cup, round 2, 2018-03-23

Click Here To Show Diagram Code

[go]$$W
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . 6 . . . . . . . . . . . . . |
$$ | . . O O O 2 . . . , . . . . . , X . . |
$$ | . O X X X O 3 . . . . . . . . . . . . |
$$ | . X . 4 1 X 5 . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

Park Yeonghun endures the squeeze in this one:

Park Yeonghun, 9p - Park Cheongsang, 9p, W+R (Komi 6.5)
19th Korean Maxim Cup, round 3, 2018-03-05

Click Here To Show Diagram Code

[go]$$W
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . 3 . . |
$$ | . . . . . . . . . . . . . . . 1 X O . |
$$ | . . . . . . . . . . . . . 9 . X O 2 . |
$$ | . . . O . . . . . , . . . . . X O 4 . |
$$ | . . . . . . . . . . . . . . . X O X . |
$$ | . . . . . . . . . . . . . . . 7 X O . |
$$ | . . . . . . . . . . . . . . . . 8 6 . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . O . . . . X , X . . |
$$ | . . . . . . . . . . . X . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

Personal conclusion up until now:

I dont like to play a very much myself.

On the receiving end, I will take the allow the squeeze option any day.

(The bots dont think there is very much difference in the Ke Jie game between allowing the squeeze or resisting. If at all they seem to favor allowing the squeeze slightly.)

Indeed, a aims for the squeeze. That is why these days you will often see the initial response move (after the 3-3 invasion) be on the "wrong" 3-4 point, because after the squeeze variation he will actually be facing the other way (down instead of to the left, in your example).

In-seong Hwang has a couple of really good lectures on the new 3-3 variations that he made for the Yunguseng Dojang, but they are currently available only to members.

(I note though that in the Kang Dongyun - Ke Jie game excerpted above, the initial response move is in the normal direction!)