Learning something useful from a joseki

This article is is an attempt to show how the actual joseki sequence is almost beside the point. When you look at a joseki, perhaps in a professional game, you shouldn't be learning the sequence, you should be looking at why the moves are good, and learning useful stuff from that. As such, I'm choosing a sequence that you might be unlikely to play for yourselves, a two space high pincer variation.

Two space high pincer

```  ------------------
| . . . . . . . . .
| . . . . . . . . .
| . . . X . . . . .
| . . . . . . . . .
| . . O . . . . . .
| . . . . . . . . .
| . . . . . . . . .
| . . . 1 . . . . .
| . . . . . . . . .
```

I'm going to talk about a single variation starting from this pincer.

First of all, think about what a pincer means. It is a violent attack on the approaching stone. Black plays this way when a simple sequence of a black extension followed by a white extension isn't satisfactory. This is probably because white is strong in the bottom left, and a white extension would work too well with that. It may also be because black is very strong towards the upper right, and the simple extension would be over concentrated. It may even just be to create trouble!

So what is white's objective now? Think about it a bit before reading on...

The answer is simple - white wants to avoid getting in too much trouble! Trouble means ending up with a weak group that can't be sacrificed. Remember, the weakness of a group is tied up with the strength or weakness of the surrounding groups, so if the white group is going to be weak, it needs to ensure that one of it's neighbours is weak also, so that it's a fair fight. Very often, a pincer is answered by dodging completely. If the black stone was on the 4-4 point, white would consider invading the corner. But here, that option isn't available. White does have enough space here to make obvious life. You might remember a sequence making two sliding extensions on the second line. But that is two moves, and so will only be possible if one of the moves is sente enough to get answered. Again, that is more of a 4-4 point sequence, where the slide towards the corner threatens to take the corner. If there was a white stone close below 1, it might also be possible, but then 1 would be dodgy. There are in fact many possible ways of fully living here, but they need to be played carefully, only if they work. If you can't tell they are going to work, play something simpler.

There's another problem with just living, which is that the group will be sealed in to the side, exerting no further influence on the game. That's not quite as bad as running out with a weak group, but it's not getting good value from that stone all the same.

So the simplest course is going to be to come out into the centre. That ensures that the two black stones are kept separate, and then whichever one isn't defended will be black's weak group, compensating for white's. So one natural move is a one point jump outwards.

Surprise!

```  ------------------
| . . . . . . . . .
| . . . . . . . . .
| . . . X . . . . .
| . . . . 2 . . . .
| . . O . . . . . .
| . . . . . . . . .
| . . . . . . . . .
| . . . 1 . . . . .
| . . . . . . . . .
```

Whats this? White didn't take my advice at all - she's played a suspicious looking move! It's suspicious because it's a knight's move, and we know those can be cut. Surely if white is cut then one of the halves will end up weak. We are going to have to think about this!

Now, if you were just learning joseki sequences, you might learn that 2 is joseki, but since it goes against our first intuition, it's much more instructive to learn why it's playable.

Lets follow the sequence. I hope black's response is fairly clear - cut! It's actually also reasonable for black to just extend along the top, but that feels rather submissive and it means that 2 has become a nice leaning move against the corner. White would then turn to attack the lower black stone, using her presumed strength in the bottom left. Somehow, the purpose of the original pincer has gone astray.

Now there are two ways to cut a knight's move, the duff way, and the right way. Which one is which?

The right way

```   ------------------
| . . . . . . . . .
| . . . . . . . . .
| . . . X . . . . .
| . . . 3 2 . . . .
| . . O 4 5 . . . .
| . . . . . . . . .
| . . . . . . . . .
| . . . 1 . . . . .
| . . . . . . . . .
```

I hope you didn't choose black 4, which would leave the stone in a ladder. That's the wrong way to cut a knight's move, pretty much always.

So now white has a problem. What to do about it? Well, we could try to rescue 2, since it's a cutting stone, but the trouble is that there's plenty of space for black to live in the corner, so I hope you don't think that would be good. If white's sole objective was to end with two separate black groups, she would have played the much less cuttable one point jump out, and had an easier time. (That is also joseki.) No, the plan was always to sacrifice 2.

So we are going to defend the other two stones. Whats your best guess about how to do that? The obvious way isn't always best, there's a nice tesuji here!

The obvious way

```  ------------------
| . . . . . . . . .
| . . . . . . . . .
| . . . X . . . . .
| . . . X O . . . .
| . . O O 1 3 . . .
| . . . . 2 . . . .
| . . . . . . . . .
| . . . X . . . . .
| . . . . . . . . .
```

I hope you aren't thinking 2 is good enough. It's crude, damages most of the aji in white original knights jump, and leaves behind a bad defect in whites shape. How white has a problem - she needs to play two moves at once - one to come out, and one to connect.

A leaning move?

``` ------------------
| . . . . . . . . .
| . . . . . . . . .
| . . . X . . . . .
| . . . 3 2 . . . .
| . . O 4 5 . . . .
| . . . . . . . . .
| . . . 6 . . . . .
| . . . 1 . . . . .
| . . . . . . . . .
```

Ok, so the joseki has white leaning on the pincer stone, that looks simple enough, black will defend it...

Not joseki?

```  ------------------
| . . . . . . . . .
| . . . . . . . . .
| . . . X . . . . .
| . . . X O . . . .
| . . O O X . . . .
| . . . . . . . . .
| . . . O . . . . .
| . . . X 1 . . . .
| . . . . . . . . .
```

"What!", you say, "thats not joseki - white's surrounded and in a mess"? Actually, it's fine. Why's that then?

Tesuji!

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

Oh, there's the tesuji. White is out into the centre with a forcing sequence: threatening to capture black's cutting stone. 8 nicely makes life along the side. Now black still has to worry that the original white cutting stone isn't cleanly captured, so much so in fact that doing so is the only next move. White is then poised to attack the two bottom black stones, and use her bottom left strength (remember why black played a pincer!) to good effect.

Now there's something that's actually worth learning. The details of the exact joseki sequence are pointless, it's tesujis that actually create the sequences.

Black may be justifiably unhappy about the sequence above, since although the top is quite big, the pincer has had 2 stones invested, and comes under attack. So the actual mainline:

Joseki

```  ------------------
| . . . . . . . . .
| . . . . . . . . .
| . . . X . . . . .
| . . . X O . . . .
| . . O O X 1 . . .
| . . . . . . . . .
| . . . O 2 . . . .
| . . . X . . . . .
| . . . . . . . . .
```

Ok, black has cleanly prevented that tesuji, and white has extended to prevent being enclosed. Now, what about the next move? This is another unintuitive one, but remember the white strength in the bottom left, that is invisible on the joseki sequence diagrams, but plays such an important role in the reason behind the sequence.

Joseki main line

```  ------------------
| . . . . . . . . .
| . . . . . . . . .
| . . . X . . 3 . .
| . . . X O . . . .
| . . O O X 1 . . .
| . . . . . . . . .
| . . . O 2 . . . .
| . . 4 X . . . . .
| . . . . . . . . .
```

Wow! It's quite instructive that a professional goes back and solidly captures the single white cutting stone. This is an example of thick play. White now finds it necessary to play 4, and black can feel happy about the pincer stone - it has effectively been answered by no less than 3 white stones, so there is no regret in discarding it.

So the next thing to learn from this sequence is to play moves like 3. Just to reinforce this, I'm going to leave you with a little problem. Suppose black is puffed up with fighting spirit, and decides to spoil whites shape.

How to punish black?

``` ------------------
| . . . . . . . . .
| . . . . . . . . .
| . . . X . . . . .
| . . . X O . . . .
| . . O O X 1 . . .
| . . . . . . . . .
| . . . O 2 . . . .
| . . 3 X . . . . .
| . . . . . . . . .
```

Your problem is to play white from this position, and find a good sequence to punish black. But remember, although this is a joseki diagram, actually it's in a whole board context. Note the shape of the general surroundings, that made the pincer get played in the first place!

Last updated Mon Feb 01 2021. If you have any comments, please email the webmaster on web-master AT britgo DOT org.