The 3-3-invasion punishment we learnt is wrong

[Knotwilg]

$$B the "punishment"
$$ ------------------
$$ | . . . . . . . . .
$$ | . . 2 3 0 9 . . .
$$ | . . O X . O . X .
$$ | . . O X 6 . . . .
$$ | . . 1 4 7 . . . .
$$ | . . 5 8 . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .

Click Here To Show Diagram Code

[go]$$B the "punishment"
$$ ------------------
$$ | . . . . . . . . .
$$ | . . 2 3 0 9 . . .
$$ | . . O X . O . X .
$$ | . . O X 6 . . . .
$$ | . . 1 4 7 . . . .
$$ | . . 5 8 . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .[/go]

Many amateurs (at least myself) have learnt to answer with because if Black descends to , White cuts at , either capturing three stones as in this diagram or capturing and making territory at the 4th line.

$$B Countering the counter
$$ ------------------
$$ | . . . . . . . . .
$$ | . . 2 4 . . . . .
$$ | . . O X 6 O . X .
$$ | . . O X 7 5 . . .
$$ | . . 1 . . . . . .
$$ | . . . 3 . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .

Click Here To Show Diagram Code

[go]$$B Countering the counter
$$ ------------------
$$ | . . . . . . . . .
$$ | . . 2 4 . . . . .
$$ | . . O X 6 O . X .
$$ | . . O X 7 5 . . .
$$ | . . 1 . . . . . .
$$ | . . . 3 . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .[/go]

However Black can counter at and gets superior shape up to , trumping White's corner territory. Compared to the proper countermeasure Black is much better off here.

$$W Proper countermeasure
$$ ------------------
$$ | . . . . . . . . .
$$ | . . . 1 5 . . . .
$$ | . . O X . O . B .
$$ | . . O X . . 6 . .
$$ | . . X 4 2 . . . .
$$ | . . . 3 . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .

Click Here To Show Diagram Code

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

This is the proper countermeasure

$$W Clamp tesuji
$$ ------------------
$$ | . . . . . . . . .
$$ | . . 3 1 2 . . . .
$$ | . . O X 4 W . X .
$$ | . . O X . . . . .
$$ | . 7 B 6 . . . . .
$$ | . . 5 . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .

Click Here To Show Diagram Code

[go]$$W Clamp tesuji
$$ ------------------
$$ | . . . . . . . . .
$$ | . . 3 1 2 . . . .
$$ | . . O X 4 W . X .
$$ | . . O X . . . . .
$$ | . 7 B 6 . . . . .
$$ | . . 5 . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .[/go]

Should Black resist, then White has the clamp tesuji. Black can resist with at but then White will cut at and the fight will favor her.

[jlt]

See also your 2018 post.

viewtopic.php?p=235905#p235905

[Uberdude]

The punishment I learnt in 2007 and have been proselytizing since is right

It's a lot of work correcting all this bad teaching, often by pros.

[John Fairbairn]

It's a lot of work correcting all this bad teaching, often by pros.

I've just done a quick check of pro books I can reach easily. This so-called straight-descent "punishment" (bad word, not used pros) is not approved of at all. Kitani describes it as an opening trap but with proper play Black stands superior (he prefers the solid connection to the tiger). Other books are similar. There are only 2 pro v. pro examples (and not new ones) in the GoGoD database.

If this descent really has been taught, I can only assume it's from a book of traps, but how about the possibility it's from some amateur who saw the pictures but couldn't read the text?

In fact, this thread seems so egregious I've three-quarters convinced myself I must have misread something. Can't read the text

[Uberdude]

It's a lot of work correcting all this bad teaching, often by pros.

I've just done a quick check of pro books I can reach easily. This so-called straight-descent "punishment" (bad word, not used pros) is not approved of at all.

I'm referring to pros who teach in the West, thinking of particularly Mingjiu Jiang (who is mentioned in one of the threads as advocating this descent) and Guo Juan.

Also checking this thread https://www.lifein19x19.com/forum/viewt ... 45#p101945 from 2012, tchan says:

I remember learning this punishment from a workshop by Kang Seung-hee 2p a few years ago.

Search for the relevant parts of her lecture:
Double Digit Kyu Workshop by Kang Seung-hee 2p part 4a
Double Digit Kyu Workshop by Kang Seung-hee 2p part 5a

at http://eurogotv.com

Whilst in that thread illuck quotes "Wu Xinyu 6p (his wording suggested it was actually the opinion of a group)" and I reference Liu Yuanbo 2p for the hane connect being correct and descend wrong.

So yes, we can dismiss this as teching from a 2p of considerably less stature than Kitani Minoru in a DDK lecture, but the trouble is this teaching (from this and other sources) seems to have permeated and ingrained many Western Go players, exhibit A being Knotwilg to whom it is so ingrained he forget he was corrected back in 2018! .

[Knotwilg]

Thanks Marcel! Really great summary.

On exhibit A - I'll admit: my unlearning includes forgetting that I had unlearned already.

[jlt]

This illustrates the fact that unlearning takes twice more time than learning.

[AloneAgainstAll]

I think correct punishment of white hane might depends on ladder. If ladder works for black, then black can cut at 4-5 (after exchange on bottom) - if white descend, then black plays at 2-6 trying to connect on 1st line with corner group, and white is pretty much screwed. If ladder does not work, then clamping tesuji as was said by Knotwilg.