In early 2013, the preparatory work for the conversion of our book into the SmartGo Book format was largely completed. Afterwards, I dedicated myself to a list of questions that had remained open from earlier phases. Although these questions were mostly related to aspects that were not essential for the main flow of our presentation, we wanted to provide answers for the sake of completeness.

However, it seems to me that Igo Hatsuyōron 120 does not like to be asked supposedly "simple" questions. Some answers will become terribly complicated ...

Already the very first question on my list was full of surprises: "What are the implications for Joachim's Ko-Semeai (type 1; 225) / (type 2; 363), when Black does not play the double throw-in during the building sequence of the hanezeki?"

It is typical for both of these ko-fights that Black lacks ko-threats, so White wins. However, if Black's top right group had only one more liberty, White could not set her hopes on fighting a ko any longer.

If Black uses the double throw-in of , and , following the path of our solution (where , and , are played the other way round), ...

... there will remain the single liberty , directed towards the hanezeki, which White must occupy, should she ever want to capture Black's group above. With Joachim's Ko-Semeai, White may use the combination of , , , instead of playing only. In our solution, however, White will not get the opportunity for using this gote-sente-combination, in order to gain two additional points in the Semeai Variation.

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If Black refrains from using the second throw-in (i.e. playing at 20), as Fujisawa Hideyuki did in his solution (detailed explanation can be found above ; 788), there will remain two -liberties, between Black's large group in the upper right, and White's upper group in the hanezeki.

However, it merely appears to be so. In fact, Black cannot pre-empt losing these two liberties, in sente for White. Both , and , threaten to capture Black's group below, so Black must take White's "outside" liberties, with , and , therewith occupying the earlier -liberties on his own.

Please remember that, in the course of the solution, the Main Semeai between White's group on the left, and Black's group in the upper right, is not affected, because White's upper group in the hanezeki also lost two of her liberties. However, Black will be worse off with Joachim's Ko-Semeai.

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Not playing any throw-in does not spoil White's shape in the hanezeki; so it is said to be disadvantageous for Black. But on the other hand, White does not get any prisoners during the building of the temporary seki.

Here, White connects at the lower cutting point, with , which is preferable, should Black choose the classical line of play. However, there are two -liberties remaining.

It is important to know in this context that White needs two moves to occupy these two -liberties - and not only one, as with the double throw-in. This fact will probably favour Black with Joachim's Ko-Semeai.

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We now know that Black will play the guzumi later, so it does not harm White to connect at the upper cutting point. As before, there are two -liberties left.

However, Black gets the opportunity to revert to the single throw-in, with a move at , which might benefit him in several cases.

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Later, especially with Joachim's Ko-Semeai, where an additional liberty for Black's group in the upper right will be decisive, White will get the opportunity to play the move of in gote. This reverts the hanezeki to the position, where only the first throw-in has been played.

Again, , and , are sente, and enforce Black to occupy the two liberties that are directed towards the hanezeki. So, in real terms, there has been only one -liberty, corresponding to White's move at , played in gote. As far as the liberty-count with Joachim's Ko-Semeai is concerned, we have found the same condition as with the double throw-in.

We still have as results for the Semeai Variation ...

• Black + 2 with no throw-in,
• Black + 1 with single throw-in, and
• Black + 3 with double throw-in;

the results for the Capture Variation are ...

• Black + 3 with no throw-in,
• Black + 4 with single throw-in, and
• Black + 5 with double throw-in.

And still we have no idea, why Fujisawa Hideyuki had chosen the single throw-in that gives the closest result of all.