🎥 The Open Skirt Dilemma: Part 2

In this video, we are going to continue talking about the concept of the open skirt. The name comes from the Japanese term susoaki. A more literal translation would be something like “opening at the hem,” but “open skirt” is the phrase that has stayed with us.

The idea is simple: you have a territorial framework that remains open on one or both sides. In the example, Black can still jump in on the second line from the left, and White may be tempted to block. So the main questions are the same as before: when is it good to block, when is it too early, should Black reduce right away, from which side should Black reduce, and when should either side think more globally instead?

Now let’s move to the second situation I want to show you. It comes from a very famous shimari joseki. Black makes the large enclosure, White attaches, there is hane, a cut, and eventually we reach this familiar shape.

If you want more details about this specific enclosure, Go Magic has several videos about it. But here we want to focus on the open-skirt problem.

Some players may wonder why Black does not simply block on the side right away. It looks large. But if Black does that, White gets a wall facing the star point on the other side, and the gap between them is enormous. White can easily come in between and destroy everything. Or White can take a more modern approach, peep first, and then play an active move that makes Black’s wall look more like a long baguette than a proper wall.

That “baguette” may still be strong, and Black may even end up attacking White later, but you have to remember that White also gets a large amount of territory on the left. So Black would need a very large compensation in influence to justify that result. That is why Black does not block immediately, but instead takes the bigger point on the side star point.

Now the same question from the previous video returns. Should White jump in right away?

Clearly not. On such an open board, a move on the second line is simply not the biggest move. There are many larger options: approaching a corner, taking a star point, or playing another major point elsewhere. If White jumps in locally and ends up with only a few points, that is not enough. Black would have taken several other big moves in the meantime, while White gets only territory and nothing more dynamic.

So if White wants to challenge this Black wall, the answer is: do not do it immediately.

White can easily imagine many larger moves elsewhere on the board, such as entering a corner or approaching a hoshi. But if White does want to approach the Black wall, it should be done more actively. A very modern idea is to play a probing move first.

If Black answers in a simple way, then White may later jump in under better conditions. If Black tries to cut White off, White can still jump, and then the awkward “baguette” shape returns again for Black. And nobody wants the baguette—except perhaps the French, and I am French.

Of course, Black can also react in a more dynamic way. Black might even say, “Fine, take those four stones.” But White is not forced to capture right away. White can still choose a bigger move elsewhere, or jump on the third line, keeping the cut as future aji. That is why this probing move is so annoying for Black.

Usually Black has several possible answers: Black can connect, Black can jump, or Black can answer more lightly. The important thing is that the probe itself is unpleasant. It pressures Black without forcing White into a small local continuation.

This brings us back to a key principle from Part 1: you reduce from the top before reducing from the bottom. If you want to approach a large framework, you usually begin from the side that limits your opponent’s growth most effectively. Starting from below too early often achieves too little. And once again, on such an open board, tenuki may still be completely reasonable because there are many points larger than immediately poking at the wall.

Now let’s look at another position.

The same joseki happened on the top side, and it is White’s turn. White already has an extension on top. So it would be reasonable to think about blocking on the second line now, because White has more support: the extension, the wall, and the group on the right side.

But should White block now, or should White still play elsewhere?

Again, the same principle applies. In the game, White played a large move elsewhere because it was on the border between White’s potential and Black’s. If Black gets that area, the two moyos become roughly balanced, but Black already has more secure territory. So White prefers to take a dynamic point first.

If Black becomes jealous and starts reducing, White can still take another very large point, perhaps even starting an attack on a nearby stone. The territorial balance shifts, but White’s game becomes much more dynamic. That is often better than spending a move too early on a passive local defense.

Now let’s move to a more advanced stage of the same game.

The position has developed. There has been fighting, White did get into the left-side territory, and now it is Black’s turn. At this stage, White’s top-side territory can hardly grow anymore. The center is no longer offering the same huge potential as before.

So now Black finally jumps in.

This is the correct timing. Black has already done enough elsewhere, there is less to gain in the center, and now the second-line reduction will actually be sente. White cannot really ignore it anymore, because if White takes a big move elsewhere, too many points on top will disappear. So White has to answer and defend the remaining territory.

That is the heart of the idea: the same move that was too small earlier becomes urgent later, once the surrounding potential has changed.

Finally, let’s look at one more example.

White is building a large potential on the right side, and it is Black’s turn. Black has many options here. Black could double pincer on the lower left, continue the attack against the White stone on the upper left, or do something about the right side.

This is exactly the kind of position that shows why the local block remains so small for so long. There are simply too many bigger moves elsewhere. If Black plays locally on the second line too soon, White can answer in a much larger area. The local follow-up is not severe enough to compete with the value of those bigger moves.

So in the game, Black followed the same principle as before: reduce from above first, and at the same time make a probing move. White answered, Black came back, and only much later did White finally decide there were no more large areas to fight over. Only then did White return to block on the second line.

By that point, White could no longer expand meaningfully in the center, and there was also important aji to consider. If White tried to capture too greedily, Black would have severe reducing moves that made the whole top-side framework dangerous. So White simply had to block.

That is the real timing.

So that is it for today’s video. I hope you now understand the main concepts behind the open skirt more clearly.

I would say there are two especially important ideas to remember.

First, when you are facing a large moyo, you usually want to reduce from the top first and only then from the bottom or side.

Second, there is the idea of double reduction: a move that grows your own potential while shrinking your opponent’s at the same time is usually extremely valuable. And of course, the same is true for your opponent as well. Very often, the most important move on the board is exactly that kind of move.

In this lesson, we only looked at two very modern examples, but these ideas apply much more broadly. I hope you will be able to use them in your own games in the future.

See you in the next video.