The Further Evolution of Amateurs' Knowledge
(2011 - 2014)
2013 - A Black Liberty Without Benefit
This kikashi () in the bamboo joint in the upper right corner has been kindly shown to us by Michael Redmond. To be aware of this kikashi is badly necessary to wholly understand the dependencies in the top right corner. Michael Redmond outlined some aspects that were previously escaped our attention, when evaluating the pros, and cons, of the hasami-tsuke in the upper right corner. First of all, and maybe most important, it is very likely - but not mandatory - that there will develop an additional liberty for Black out of the kikashi. White has two options for her answer: |
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A - White plays the atari. Black gets an additional liberty (in the case he wants to live); White gets the option of gaining points (mostly in the case she does not want to kill) by capturing at least Black's hasami-tsuke stone . This ambivalence is valid throughout the entire treatment of this topic, as far as the main line of our solution is concerned. But - with Michael Redmond's kikashi in the bamboo joint already played - White must be on her guard to start the endgame in the upper left corner in time. Otherwise, she might lose points unnecessarily. If Black chooses Joachim's Ko-Semeai, Black's kikashi and White's atari just lead to a change in the order of moves. There is no additional liberty for Black, with regard to this special semeai. |
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C - White connects solidly. There is no additional liberty for Black. White will be unable to get additional profit. This will result in a change in the order of moves, as far as the main line of our solution is concerned. However, this is true with the main path of our solution only. With Joachim's Ko-Semeai, White will be at a disadvantage hereafter. Unnecessarily, and unforced, she now needs one more move () to occupy Black's outside liberties. This is due to the fact that Black - sooner or later - will connect his stone on the upper edge, with a move at , as a rule compelled by a White forcing-move. |
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The decision between , and , is White's authority only. However, the potential threat of Joachim's Ko-Semeai takes care that White will choose . There is nothing that Black could do with reference to the later additional liberties, too. White is not forced to let Black have what he wants. Best for White are profit-gaining spots on the left side of the board, because these are independent of her later choice between Capture, and Semeai, Variation. Black is in a large dilemma. He cannot enforce either White to let him have three additional liberties, or White to choose the Semeai Variation. But he needed both to be successful. In our solution, the Capture Variation is two points worse for White than the Semeai Variation. We surely can expect that White will gain a compensation of at least one point per additional move / liberty that she lets Black get (otherwise she would not follow Black). Black needs three additional moves / liberties, so White will gain at least three points of compensation. So, the Capture Variation becomes one point better for White than the Semeai Variation (under the assumption that the compensation is not valid in both main variations), and she will no longer choose the Semeai Variation, but the Capture Variation, instead. In this case, there is no semeai in the upper right. Black has got three additional liberties for his group there that he did not ever need before for White choosing the Capture Variation. So, in a certain sense, Black provided profit to White for nothing. In the problem, White's compensation will be larger than only one point each (but three, or four, points), so White will win the game, if Black insisted on gaining the three additional moves / liberties. Therefore, White will be happy with following Black for each additional liberty that Black wants to gain. | |
As late as mid-2015, when examinating the consequences of Michael Redmond's kikashi on some sub-variations that end with White choosing the Punishment Semeai successfully, we realised that the liberty-gaining effect of the kikashi - seen in the relationship between White's atari vs. her solid connection - is eliminated, if Black either played the guzumi ( / here), or got an eye by capturing one of White's single stones in the upper right. With the atari of played, White can approach Black's group on the upper edge easily, by capturing Black's hasami-tsuke stones first. The potential approach-move liberty near the guzumi will not become a real liberty. Black's group has 14 liberties in the marked area. | |
White the solid connection of played, White cannot directly approach Black's group on the upper edge easily, due to the characteristics of Black's hasami-tsuke (she would need an approach-move in that area, if she preferred that line of play). The approach-move liberty near the guzumi will become a real liberty. Black's group has 14 liberties in the marked area, as many as in the previous diagram. In the case that Black captured one of White's single stones (e.g. ), instead of playing the guzumi ( / ), Black's newly won eye-point has the same characteristics as the approach-move liberty of here. Again - as far as the liberty count is concerned - there will be no difference between atari, and solid connection. | |