Doug Ridgway: This proverb doesn't make sense to me. If either cut will work, and the opponent can only protect against one of them, then regardless of which side I want, it's the opponent who gets to choose which side I will get. Wouldn't it be better to cut on the side that the opponent will end up giving me anyway? That way, the opponent doesn't get to capture a stone, which is better for them than for me.
In the original example, if White wants the outside, then isn't this better for Black than the original?
Or alternatively, tewari-style, the - exchange is obviously bad for black. (I hope this isn't Lying With Tewari.)
Andre Engels: Yes the diagram "Better for Black" is, and that is exactly what the proverb is about: If White is going to take the outside anyway, then apparently the outside is more important than the inside, so it is the side that you want. And if you want the outside, the proverb tells you to cut on the inside - which is exactly what you are doing here.
Charles: You have to look at the line where White resists Black's chosen plan:
Here White should be in trouble, because the corner is just about to die. White denies Black the corner, indeed; but the cost is too high even if the ladder for Black to capture is bad.
Doug Ridgway: I agree, so White won't do that, and will let Black have the corner if Black cuts on the outside. But would White take the corner if Black cuts on the inside?
It's easier for White to live now, and the outside stone isn't dead yet, so maybe White would do this. If so, then maybe the original cut on the outside is correct, as a sacrifice to convince White to give Black the corner. Otherwise, if Black gets the corner in any case, it seems to me that the original cut on the outside is a One-Two-Three mistake.
Charles: This is (perhaps obsolescent) joseki, but only if Black has a good ladder at a to capture: here isn't adequate.
If it's joseki, then it's OK, so let's look at joseki.
The original position can arise from 3-5 point 3-3 approach when Black attaches at . Kogo states that Black needs the ladder even before attaching at 3. With no ladder, the best he can do is cut at a and take the corner, but the result favors White (according to Kogo). With the ladder, he cuts at b and takes the outside. What I find interesting is that the paths with White connecting don't even appear -- as far as the joseki book is concerned, White will always capture, never connect. (If I did the search right.)
Gobase can find only one of these joseki actually played: the inside cut followed by the ladder, and in only one game. Most popular is Black a White c Black d, and Black a White b has also been played. Maybe this is an example of there's no such thing as joseki?.
Andre Engels: I am a bit at a loss at what you're saying. What do you mean by 'these joseki' when you say that Gobase can only find one of these joseki actually being played? Anyway, my own joseki database (consisting of MasterGo's database plus games downloaded from the Internet plus games typed in by me from magazines, totalling slightly over 20,000), I find the following variations:
Here's another example, a position which occurred in one of my games. Suppose White decides to cut: a or b? I think Black will connect on the bottom, regardless of which side White starts on: it's easier to live, and there's more White territory to threaten. So White should cut at a, as this is the side that Black will give up. White a, Black b, White c is what I would expect. Does this make sense?
Charles: Given your hypothesis about Black's intention, yes, it makes sense.
Dieter: If you capture the cutting stone, it will be easier to live regardless of the surroundings. There are of course occasions on which Black will not capture the cutting stone, because giving White what she wants more than offsets the advantage of capturing the cutting stone. In your example however, that is not the case. I will capture the cutting stone without even thinking.
togo: The shape is secondary here, capturing the cutting stone in these cases gives an additional move.
JoelR: No, in every variation of example 1 above (White connects or White captures), Black ends in gote.
: Charles: This sort of lacuna in joseki books, where they don't explain or indicate the most fundamental points, is very typical: too much of the wrong type of data for some users.