My question is, why is this white angle contact play NOT joseki

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[go]$$B
$$ ------------------
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . 2 . . 3 .
$$ | . . 1 4 . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .[/go]

The reason I ask about this, is that 1) I recently had it played against me, and 2) strangely it is joseki for almost all the other pincers, 1 space high and low, 2 space high, 3 space high and low. It's only the 2 space low pincer that nothing is given in my big joseki dictionary. There are only 9 occurrences in my database. One of them was kitani but it seems clear that for some reason this reply to this particular pincer is taboo.

I am sure that there are circumstances when it can be played, but after this sequence black cannot expand along the top like he can with a high pincer, so right away is one reason it is not optimal.

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[go]$$B
$$ ------------------
$$ | . . . . . . . . .
$$ | . 9 8 . . . . . .
$$ | . 7 6 . 2 . . 3 .
$$ | . . 1 4 . . . . .
$$ | . . 5 . . . . . .
$$ | . . . . . . . . .[/go]

_________________
Still officially AGA 5d but I play so irregularly these days that I am probably only 3d or 4d over the board (but hopefully still 5d in terms of knowledge, theory and the ability to contribute).

Another consideration is that, because white can't expand on the top due to being low and closer...

Click Here To Show Diagram Code

[go]$$B
$$ ------------------
$$ | . . . . . . . . .
$$ | . a 8 . . . . . .
$$ | . 7 6 . 2 . . 3 .
$$ | . . 1 4 . . . . .
$$ | . . 5 . . . . . .
$$ | . . . . . . . . .
$$ | . . . 9 . . . . .
$$ | . . . . . . . . .[/go]

A move like is pretty sente against the corner, calling for white a to stabilise the group. Black can likely then seal white in, or if white omits it, get the white group running.

With a high or farther pincer, white has miai between A and a move to the right to live, whether a slide or one space jump.

Note also that is a pretty defensive move, generally played because white can't fight favourably in the corner and adjacent area due to black strength or other considerations, so white wants to settle quickly and avoid becoming a target.

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[go]$$B Transposition
$$ ------------------
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . 7 6 . 2 . . 3 .
$$ | . . 1 4 . . . . .
$$ | . . 5 . . . . . .
$$ | . . . . . . . . .[/go]

This sequence is a transposition of the following sequence, . . .

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[go]$$B Joseki
$$ ------------------
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . 5 4 . 2 . . 3 .
$$ | . . 1 6 . . . . .
$$ | . . 7 . . . . . .
$$ | . . . . . . . . .[/go]

which is joseki.

So perhaps the reason it is not joseki has to do with this reply.

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[go]$$B Non joseki
$$ ------------------
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . 5 . 2 . . 3 .
$$ | . . 1 4 . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .[/go]

Above my pay grade.

_________________
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins

Visualize whirled peas.

Everything with love. Stay safe.

I looked at this before replying. This move is joseki for other positions of the pincer. But I think it is harder for white to reply at a now for much the same reasons as earlier and so he must play b. That's why I chose to comment on the simpler variation. I think this one has the potential to get much nastier for white.

_________________
Still officially AGA 5d but I play so irregularly these days that I am probably only 3d or 4d over the board (but hopefully still 5d in terms of knowledge, theory and the ability to contribute).

Yeah, where is White's base?

_________________
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins

Visualize whirled peas.

Everything with love. Stay safe.