User talk:Gaav42

3-3 invasion.
The cited Sensei's library article merely states that the invasion is not to be feared. So can not be taken to mean that white has a weaker position. What does Kageyame say? I can not remember reading him to the understanding that a 3-3 invasion is bad.

Ishida does include 3-3 as a joseki.

Taemyr 12:19, 7 November 2007 (UTC)

The Sensei's Library article states that "This result is regarded as good for Black locally, but is often White's best choice, nonetheless". Of course the 3-3 invasion is often a good choice. But when the surrounding position is empty, as in the diagram, the result is better for black.

In the chapter called "The Struggle to Get Ahead", Kageyama talks about situations where both black and white run side by side in one direction (called pushing battles on sensei's). After some other examples, he gives the exact position shown in the article. He then says:

"This shoulder-to-shoulder position arises in actual play when white invades immediately in the three-three-point under black's four-four-point stone. [He continues to say that white shouldn't cut back, but bend down after black's first hane.] The sequence walks itself out to 12 and comes to a pause, with White getting actual profit and Black getting outer influence. Whose result is better? That should go without saying, but I'll say it: Black's is definitely better. For that reason White never invades immediately at the three-three-point under a black four-four point stone, except in special circumstances."

I've looked in Ishida Volume III, but couldn't find the 3-3 invasion there, only invasions with additional stones around.

I think the misunderstanding here is probably that the surrounding position must not be settled for black's result to be better. If white had a settled position just outside the scope of the diagram, as he has sente after this invasion, he could move in to reduce black's thickness. However, as these stones are not shown, and would have to be to be taken into consideration, the result cannot be called equal. I didn't mean to say that the 3-3 invasion shouldn't be played: it is certainly very often advantageous to invade san-san. You just don't do it as a second move, because if you do, the result is better for black. --Gaav42 22:48, 7 November 2007 (UTC)


 * Hmm, if white has a settled group outside the diagram then an approach would most likely be too close to thickness. The most common situation where the 3-3 invasion is meaningful is in a double wing formation with 4-4 and both adjacent star points.  Taemyr 23:42, 7 November 2007 (UTC)

If the position is settled, a two-space extension in the direction of black's thickness would probably never be too close, just too small, depending on the whole board. Of course, black's influence cannot be nullified by jumping right in the middle. Black should counter-invade then. And I agree: A double-wing formation based on a star point is a good reason to invade 3-3. Locally, the result is even better for black, but that is natural considering he has spent 3 more moves there. After the invasion of the double-wing formation, black wishes he could put one stone elsewhere - the stone he has played on the side that he has not blocked on. This stone has become inefficient. This, and the fact that black still had 2 stones in place at the beginning, probably make this a Joseki IMHO. Gaav42 00:48, 8 November 2007 (UTC)


 * The reason not to play close to thickness is that it's hard to make points there. In the case of the double wing formation I consider it more important that the stone on the side that you have blocked on is to narrow than the relative misplacement of the stone on the other sides.  This is an important point in the chinese fuseki. Taemyr 10:49, 8 November 2007 (UTC)

Agreed. I just watched "All About Invasion Lecture 16 (3-3)" on Guo Juan's Audio Go Lecture site. They said the same thing: If the board is empty, an immediate 3-3 invasion is not good for the invader. If black has a double-wing formation with 3 star points, the invasion is very good, because both center star points are too close. If there is only one center star point, they say the invasion is probably OK, because the stone will still be too close. Unfortunately, this site is also not very accessible, because you have to register and also pay at least 5 Euro via Paypal before you can watch this lecture (you will get 4 more lectures for your money, though). --Gaav42 (talk) 21:35, 19 November 2007 (UTC)