How much should I avoid learning Josekis as a beginner?

[supernerd]

Greetings,

I have heard that double digit kyus should not study Joseki but wait until anywhere from 9k to 1d depending on who you ask. Supposedly it is to avoid the trap of rote learning patterns without really understanding why they work or how context alters their application. (EDIT: I am 19 ky on kgs btw)

I was intending to wait until at least 9k before learning josekis. Unfortunately I accidently learned the basic Joseki for san-san invasion when the oppoenent has a single stone on 4-4, because someone showed me this on kgs. Now I cannot ever unsee it. (I have tried)

Is this a bad thing? I have been able to use this joseki succesfully as both attacker and defender in a couple games, and punish a few opponents who didn't follow the joseki. It is such a basic and intuitive sequence that I feel I really do understand it. Also, know I don't know how I lived without it, since it has been so useful.

I also have begun to involentarily pick up the start of a couple few joseki against the knights jump attack against the hoshi from exposure to this in kgs game reviews. I am tempted to try and learn some of these because I get these attacks alot and usually fumble blindly against them. However, I have been wary because of the above advice.

Today, however, curiosity and the allure of forbidden knowledge got the better of me, and I peeked into my friend's basic book on Joeski for about an hour. This was really interesting but there are so many complex things I see why I should hold off.

However, I think I could still benefit from learning just two or three more of the really simple and common joseki's at my current level, and not harm myself too much.

What do you guys think?

[illluck]

I think you are talking the advice a tad too literally

The idea is that it's not very productive to go out your way to "learn" joseki by rote memorization in isolation (partly because if you do it that way you will generally have difficulties if your opponent deviates), but instead to understand common sequences and such through application in real games. From what you are describing, it seems like you are learning joseki the right way

[Bill Spight]

Learning joseki is not a bad thing. As long as you don't play them.

The danger is that joseki can restrict your thinking. You learn what is right in general and apply it in situations where it is wrong.

IMX I can see the problem of restricted thinking among SDKs, whether they have studied joseki or not. They struggle to decide which is better, A or B, when they have not even thought about C, which is correct. The situation is even worse when A is joseki, so that they play it automatically.

As a beginner you can make rapid progress by learning standard plays, including joseki. But the most important thing is to think for yourself.

[Uberdude]

basic Joseki for san-san invasion when the oppoenent has a single stone on 4-4 ... that I feel I really do understand it.

A little test

Question 1:

is a mistake, it should be a first. Why? How should black take advantage?

$$W
$$ ------------------
$$ | . . . . . . . . .
$$ | . . . 1 . . . . .
$$ | . . O X . . . . .
$$ | . . O X . . . . .
$$ | . a X . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .

Click Here To Show Diagram Code

[go]$$W
$$ ------------------
$$ | . . . . . . . . .
$$ | . . . 1 . . . . .
$$ | . . O X . . . . .
$$ | . . O X . . . . .
$$ | . a X . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .[/go]

Question 2:

Is black 2 good or bad? Why?

$$W
$$ ------------------
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . O X . . . . .
$$ | . . O X . . . . .
$$ | . O X . . . . . .
$$ | . 1 X . . . . . .
$$ | . 2 . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .

Click Here To Show Diagram Code

[go]$$W
$$ ------------------
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . O X . . . . .
$$ | . . O X . . . . .
$$ | . O X . . . . . .
$$ | . 1 X . . . . . .
$$ | . 2 . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .[/go]

Question 3:

Why is push once at 1 joseki

$$W
$$ ------------------
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . O X . . . . .
$$ | . . O X . . . . .
$$ | . O X . . . . . .
$$ | . 1 X . . . . . .
$$ | . . 2 . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .

Click Here To Show Diagram Code

[go]$$W
$$ ------------------
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . O X . . . . .
$$ | . . O X . . . . .
$$ | . O X . . . . . .
$$ | . 1 X . . . . . .
$$ | . . 2 . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .[/go]

but pushing another time at is bad?

$$W
$$ ------------------
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . O X . . . . .
$$ | . . O X . . . . .
$$ | . O X . . . . . .
$$ | . 1 X . . . . . .
$$ | . 3 2 . . . . . .
$$ | . . 4 . . . . . .
$$ | . . . . . . . . .

Click Here To Show Diagram Code

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

Question 4:

Why does black play ? Why not a? Why not tenuki?

$$W
$$ ------------------
$$ | . . . . . . . . .
$$ | . . 3 1 2 . . . .
$$ | . . O X a 4 . . .
$$ | . . O X . . . . .
$$ | . O X . . . . . .
$$ | . O X . . . . . .
$$ | . . X . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .

Click Here To Show Diagram Code

[go]$$W
$$ ------------------
$$ | . . . . . . . . .
$$ | . . 3 1 2 . . . .
$$ | . . O X a 4 . . .
$$ | . . O X . . . . .
$$ | . O X . . . . . .
$$ | . O X . . . . . .
$$ | . . X . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .[/go]

Studying joseki (I think that's a better verb than learning) means understanding the moves so you can answer these questions (and more!) correctly.

[Mike Novack]

What Uberdude has posted is very much to the point.

When you say "learn joseki", precisely what do you mean by that. If what you mean is just memorizing sequences (the right next move assuming that the opponent made the previous "right move") to save time (for when more thinking is necessary) even then you would need to know the variants in terms of which goes with what outside situation (the whole board matters)

But if what was meant was studying to understand why each move in the sequence is "joseki" and when variation is possible (and why; what outside factors change what is feasible, for example, ladder breakers) and what to do if the opponent doesn't play the expected move --- well that's another kettle of fish entirely.

That sort of study isn't just about joseki.

[illluck]

Question 1:

is a mistake, it should be a first. Why? How should black take advantage?

$$W
$$ ------------------
$$ | . . . . . . . . .
$$ | . . . 1 . . . . .
$$ | . . O X . . . . .
$$ | . . O X . . . . .
$$ | . a X . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .

Click Here To Show Diagram Code

[go]$$W
$$ ------------------
$$ | . . . . . . . . .
$$ | . . . 1 . . . . .
$$ | . . O X . . . . .
$$ | . . O X . . . . .
$$ | . a X . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .[/go]

Is that one really a mistake? Do you mean the below instead?

$$W
$$ ------------------
$$ | . . . . . . . . .
$$ | . . 3 1 2 . . . .
$$ | . . O X . . . . .
$$ | . . O X . . . . .
$$ | . a X . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .

Click Here To Show Diagram Code

[go]$$W
$$ ------------------
$$ | . . . . . . . . .
$$ | . . 3 1 2 . . . .
$$ | . . O X . . . . .
$$ | . . O X . . . . .
$$ | . a X . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .[/go]

Edit:

For example, the below looks ok for white?

$$W
$$ ------------------
$$ | . . . . . . . . .
$$ | . . . 1 3 . . . .
$$ | . . O X . . . . .
$$ | . . O X . . . . .
$$ | . . X 2 . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .

Click Here To Show Diagram Code

[go]$$W
$$ ------------------
$$ | . . . . . . . . .
$$ | . . . 1 3 . . . .
$$ | . . O X . . . . .
$$ | . . O X . . . . .
$$ | . . X 2 . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .[/go]

[Uberdude]

Is that one really a mistake? Do you mean the below instead?

$$W
$$ ------------------
$$ | . . . . . . . . .
$$ | . . 3 1 2 . . . .
$$ | . . O X . . . . .
$$ | . . O X . . . . .
$$ | . a X . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .

Click Here To Show Diagram Code

[go]$$W
$$ ------------------
$$ | . . . . . . . . .
$$ | . . 3 1 2 . . . .
$$ | . . O X . . . . .
$$ | . . O X . . . . .
$$ | . a X . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .[/go]

Yes it's a mistake*, though the question I wanted supernerd to answer was indeed after white connecting at 3.

*

because if black double hanes and white takes the ponuki on the left side it becomes a bad move, otherwise it can revert to joseki. If a move can only revert to joseki or give an inferior result it's a mistake.

[supernerd]

Here are my answers. It wasn't immediately obvious; I had to think a lot and play stuff out and I'm still not sure their right. Maybe I don't understand this joseki as well as I had thought.

Question 1:

is a mistake, it should be a first. Why? How should black take advantage?

This is interesting. I think that black can play at 2, which threatens the cut at b. White cut at a cant work. If white connects at b to avoid cut black plays at c (or maybe d to avoid countercut?) which cramps white and makes it difficult to live. If white instead plays c black cuts at b which means white dies in the corner, but can run on the right. I guess that could be worth it given some contexts, but generally it seems white will make less territory than with the joseki while still managin to strengthen black. Also trying to make territory on the second line sucks a little bit.

$$W
$$ ------------------
$$ | . . . . . . . . .
$$ | . . b 1 c . . . .
$$ | . . O X d . . . .
$$ | . 2 O X . . . . .
$$ | . a X . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .

Click Here To Show Diagram Code

[go]$$W
$$ ------------------
$$ | . . . . . . . . .
$$ | . . b 1 c . . . .
$$ | . . O X d . . . .
$$ | . 2 O X . . . . .
$$ | . a X . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .[/go]

Question 2:

Is black 2 good or bad? Why?

This is seems bad. White can cut at a which is very scary for black, because there is the cut at b is threatened. This starts a really nasty fight, but I think white can always gain from the fight and kill/trade some black stones since black has 3 groups that can be threatened.( At least as far as I can tell trying to play out the numerous variations. This seems really complicated.)

$$W
$$ ------------------
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . O X . . . . .
$$ | . . O X . . . . .
$$ | . O X b . . . . .
$$ | . 1 X . . . . . .
$$ | . 2 a . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .

Click Here To Show Diagram Code

[go]$$W
$$ ------------------
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . O X . . . . .
$$ | . . O X . . . . .
$$ | . O X b . . . . .
$$ | . 1 X . . . . . .
$$ | . 2 a . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .[/go]

Question 3:

Why is push once at 1 joseki
but pushing another time at is bad?

This is a hard one for me. Maybe it lets black play at a but the cut at b is not so effective so this reduces white's territory but isn't fatal. Meanwhile white can play at c and run out. So I don't think black would play at a. Is that is why you show black playing at c? Why not d?

The only other reason I can think of is strategic. A san-san invasion gives black a lot of thickness, and white does not need to push out an extra time to live. Maybe this extra point of territory is not worth the strength it gives black at this point, and white should take a minimilist approach and just live.

$$W
$$ ------------------
$$ | . . . . . . . . .
$$ | . . a . . . . . .
$$ | . . O X . . . . .
$$ | . b O X . . . . .
$$ | . O X . . . . . .
$$ | . 1 X . . . . . .
$$ | . 3 2 . . . . . .
$$ | . d c . . . . . .
$$ | . . . . . . . . .

Click Here To Show Diagram Code

[go]$$W
$$ ------------------
$$ | . . . . . . . . .
$$ | . . a . . . . . .
$$ | . . O X . . . . .
$$ | . b O X . . . . .
$$ | . O X . . . . . .
$$ | . 1 X . . . . . .
$$ | . 3 2 . . . . . .
$$ | . d c . . . . . .
$$ | . . . . . . . . .[/go]

Question 4:

Why does black play ? Why not a? Why not tenuki?

The cut at a is really dangerous for black here if he tenukis (also if white cuts at a he is also threatening the cut at b. If he plays at a it seems ok, but it is slow. does the same thing as a but is bigger.

$$W
$$ ------------------
$$ | . . . . . . . . .
$$ | . . 3 1 2 . . . .
$$ | . . O X a 4 . . .
$$ | . . O X . . . . .
$$ | . O X b . . . . .
$$ | . O X . . . . . .
$$ | . . X . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .

Click Here To Show Diagram Code

[go]$$W
$$ ------------------
$$ | . . . . . . . . .
$$ | . . 3 1 2 . . . .
$$ | . . O X a 4 . . .
$$ | . . O X . . . . .
$$ | . O X b . . . . .
$$ | . O X . . . . . .
$$ | . . X . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .[/go]

[oren]

No reason to avoid learning anything you want to learn. If you think studying joseki will be fun, do it.

[oca]

Hey nice exercice, here are my answers too...

Question 1
Had no idea but read the answer so I cannot play anymore

Question 2:

$$W
$$ ------------------
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . O X . . . . .
$$ | . . O X . . . . .
$$ | . O X . . . . . .
$$ | . 1 X . . . . . .
$$ | . 2 a . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .

Click Here To Show Diagram Code

[go]$$W
$$ ------------------
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . O X . . . . .
$$ | . . O X . . . . .
$$ | . O X . . . . . .
$$ | . 1 X . . . . . .
$$ | . 2 a . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .[/go]

if white cut at a, that may lead to complications for black ...

$$W
$$ ------------------
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . O X . . . . .
$$ | . . O X . . . . .
$$ | . O B . . . . . .
$$ | . O B . . . . . .
$$ | . B 1 . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .

Click Here To Show Diagram Code

[go]$$W
$$ ------------------
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . O X . . . . .
$$ | . . O X . . . . .
$$ | . O B . . . . . .
$$ | . O B . . . . . .
$$ | . B 1 . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .[/go]

Question 3:

Why is push once at 1 joseki

Because white need that space to live.

$$W 5 tenuki
$$ ------------------
$$ | . . . . . . . . .
$$ | . . 3 1 2 . . . .
$$ | 8 . O X . 4 . . .
$$ | . 7 O X . . . . .
$$ | . O X . . . . . .
$$ | . 6 X . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .

Click Here To Show Diagram Code

[go]$$W 5 tenuki
$$ ------------------
$$ | . . . . . . . . .
$$ | . . 3 1 2 . . . .
$$ | 8 . O X . 4 . . .
$$ | . 7 O X . . . . .
$$ | . O X . . . . . .
$$ | . 6 X . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .[/go]

but pushing another time at is bad?
Give to much influence for few territory in return.


Question 4
Why does black play ? Why not a? Why not tenuki?

tenuki will allow to cut

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

Click Here To Show Diagram Code

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

$$W 4 at a
$$ ------------------
$$ | . . . . . . . . .
$$ | . . 3 1 2 . . . .
$$ | . . O X 4 . . 5 .
$$ | . . O X . . . . .
$$ | . O X . . . . . .
$$ | . O X . . . . . .
$$ | . . X . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .

Click Here To Show Diagram Code

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

Not sure... seems not as bad as tenuki, but I think but that may allow white to play 5 and black cannot use its wall at its full potential I think....

[Bill Spight]

Question 1:

is a mistake, it should be a first. Why? How should black take advantage?

$$W
$$ ------------------
$$ | . . . . . . . . .
$$ | . . . 1 . . . . .
$$ | . . O X . . . . .
$$ | . . O X . . . . .
$$ | . a X . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .

Click Here To Show Diagram Code

[go]$$W
$$ ------------------
$$ | . . . . . . . . .
$$ | . . . 1 . . . . .
$$ | . . O X . . . . .
$$ | . . O X . . . . .
$$ | . a X . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .[/go]

Is that one really a mistake? Do you mean the below instead?

$$W
$$ ------------------
$$ | . . . . . . . . .
$$ | . . 3 1 2 . . . .
$$ | . . O X . . . . .
$$ | . . O X . . . . .
$$ | . a X . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .

Click Here To Show Diagram Code

[go]$$W
$$ ------------------
$$ | . . . . . . . . .
$$ | . . 3 1 2 . . . .
$$ | . . O X . . . . .
$$ | . . O X . . . . .
$$ | . a X . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .[/go]

Edit:

For example, the below looks ok for white?

$$W
$$ ------------------
$$ | . . . . . . . . .
$$ | . . . 1 3 . . . .
$$ | . . O X . . . . .
$$ | . . O X . . . . .
$$ | . . X 2 . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .

Click Here To Show Diagram Code

[go]$$W
$$ ------------------
$$ | . . . . . . . . .
$$ | . . . 1 3 . . . .
$$ | . . O X . . . . .
$$ | . . O X . . . . .
$$ | . . X 2 . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .[/go]

$$W
$$ ------------------
$$ | . . . . . . . . .
$$ | . . . W O . . . .
$$ | . . O B . . . . .
$$ | . . O X . . . . .
$$ | . . X X . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .

Click Here To Show Diagram Code

[go]$$W
$$ ------------------
$$ | . . . . . . . . .
$$ | . . . W O . . . .
$$ | . . O B . . . . .
$$ | . . O X . . . . .
$$ | . . X X . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .[/go]

The - exchange is bad for Black.

[Uberdude]

Here is a better version of question 1:

White thinks this is the joseki:

$$W
$$ ------------------
$$ | . . . . . . . . .
$$ | . . 3 1 2 . . . .
$$ | . . O X . 4 . . .
$$ | . . O X . . . . .
$$ | . 5 X . . . . . .
$$ | . 7 6 . . . . . .
$$ | . . 8 . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .

Click Here To Show Diagram Code

[go]$$W
$$ ------------------
$$ | . . . . . . . . .
$$ | . . 3 1 2 . . . .
$$ | . . O X . 4 . . .
$$ | . . O X . . . . .
$$ | . 5 X . . . . . .
$$ | . 7 6 . . . . . .
$$ | . . 8 . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .[/go]

But he is wrong and made a mistake, but also black let white get away with it. What did white do wrong and how should black have punished?

[Uberdude]

Marks for supernerd:

Question 1:

is a mistake, it should be a first. Why? How should black take advantage?

This is interesting. I think that black can play at 2, which threatens the cut at b. White cut at a cant work. If white connects at b to avoid cut black plays at c (or maybe d to avoid countercut?) which cramps white and makes it difficult to live. If white instead plays c black cuts at b which means white dies in the corner, but can run on the right. I guess that could be worth it given some contexts, but generally it seems white will make less territory than with the joseki while still managin to strengthen black. Also trying to make territory on the second line sucks a little bit.

$$W
$$ ------------------
$$ | . . . . . . . . .
$$ | . . b 1 c . . . .
$$ | . . O X d . . . .
$$ | . 2 O X . . . . .
$$ | . a X . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .

Click Here To Show Diagram Code

[go]$$W
$$ ------------------
$$ | . . . . . . . . .
$$ | . . b 1 c . . . .
$$ | . . O X d . . . .
$$ | . 2 O X . . . . .
$$ | . a X . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .[/go]

Your 2 is interesting, you say cut at a can't work, but if white cuts and you capture it then white can atari the other side and then capture 2 stones in a ladder which is good for her. Instinct should be to block at c, see my re-worded question 1.

Question 2:

Is black 2 good or bad? Why?

This is seems bad. White can cut at a which is very scary for black, because there is the cut at b is threatened. This starts a really nasty fight, but I think white can always gain from the fight and kill/trade some black stones since black has 3 groups that can be threatened.( At least as far as I can tell trying to play out the numerous variations. This seems really complicated.)

$$W
$$ ------------------
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . O X . . . . .
$$ | . . O X . . . . .
$$ | . O X b . . . . .
$$ | . 1 X . . . . . .
$$ | . 2 a . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .

Click Here To Show Diagram Code

[go]$$W
$$ ------------------
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . O X . . . . .
$$ | . . O X . . . . .
$$ | . O X b . . . . .
$$ | . 1 X . . . . . .
$$ | . 2 a . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .[/go]

Yeah, it's bad, the cut is too much trouble (unless you have friendly stones nearby to capture it).

Question 3:

Why is push once at 1 joseki
but pushing another time at is bad?

This is a hard one for me. Maybe it lets black play at a but the cut at b is not so effective so this reduces white's territory but isn't fatal. Meanwhile white can play at c and run out.

Right, a isn't a big deal (white can answer once and then if black connects tenuki to c which is bigger as you say.

So I don't think black would play at a. Is that is why you show black playing at c? Why not d?

$$W
$$ ------------------
$$ | . . . . . . . . .
$$ | . . a . . . . . .
$$ | . . O X . . . . .
$$ | . b O X . . . . .
$$ | . O X . . . . . .
$$ | . 1 X . . . . . .
$$ | . 3 2 . . . . . .
$$ | . d c . . . . . .
$$ | . . . . . . . . .

Click Here To Show Diagram Code

[go]$$W
$$ ------------------
$$ | . . . . . . . . .
$$ | . . a . . . . . .
$$ | . . O X . . . . .
$$ | . b O X . . . . .
$$ | . O X . . . . . .
$$ | . 1 X . . . . . .
$$ | . 3 2 . . . . . .
$$ | . d c . . . . . .
$$ | . . . . . . . . .[/go]

See your answer to question 2

The only other reason I can think of is strategic. A san-san invasion gives black a lot of thickness, and white does not need to push out an extra time to live. Maybe this extra point of territory is not worth the strength it gives black at this point, and white should take a minimilist approach and just live.

Excellent answer. But white doesn't actually need the first push to live either, so why play that one?

Question 4:

Why does black play ? Why not a? Why not tenuki?

The cut at a is really dangerous for black here if he tenukis (also if white cuts at a he is also threatening the cut at b. If he plays at a it seems ok, but it is slow. does the same thing as a but is bigger.

$$W
$$ ------------------
$$ | . . . . . . . . .
$$ | . . 3 1 2 . . . .
$$ | . . O X a 4 . . .
$$ | . . O X . . . . .
$$ | . O X b . . . . .
$$ | . O X . . . . . .
$$ | . . X . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .

Click Here To Show Diagram Code

[go]$$W
$$ ------------------
$$ | . . . . . . . . .
$$ | . . 3 1 2 . . . .
$$ | . . O X a 4 . . .
$$ | . . O X . . . . .
$$ | . O X b . . . . .
$$ | . O X . . . . . .
$$ | . . X . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .[/go]

Right we should defend the cut, and is bigger, extends further. Another plus for it is it has more eyeshape. Also can you see a difference in the endgame?

[Uberdude]

oca, in question 3 your 8 doesn't kill, can you see how to live? Given that why push?

[oca]

oca, in question 3 your 8 doesn't kill, can you see how to live? Given that why push?

by push, do you mean like that ?

$$W 5 tenuki
$$ ------------------
$$ | . . . . . . . . .
$$ | . . 3 1 2 . . . .
$$ | 8 . O X . 4 . . .
$$ | . 7 O X . . . . .
$$ | . O X . . . . . .
$$ | 9 6 X . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .

Click Here To Show Diagram Code

[go]$$W 5 tenuki
$$ ------------------
$$ | . . . . . . . . .
$$ | . . 3 1 2 . . . .
$$ | 8 . O X . 4 . . .
$$ | . 7 O X . . . . .
$$ | . O X . . . . . .
$$ | 9 6 X . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .[/go]