Problem No. 120 from Igo Hatsuyoron
By Inoue Dosetsu Inseki (1646 - 1719)
Black to play and win |
Black to play and win |
B 23, W 24: Both Black and White follow the course of the Main Path. W 26: One road to Semeai starts with this move at the other 2-1-point of the bottom right corner. [ see variation ] |
Dia. 19e.5: B 23 - W 32 |
Dia. 19e.6: B 33 - W 42 |
|
Dia. 19e.7: B 43 - W 52 |
|
Dia. 19e.8: B 53 - W 62 |
|
Dia. 19e.8a: B 63 - B 71 |
|
W 72: Instead of saving her centre group White could start the Semeai with the Black group in the upper right. [ see variation ] |
Dia. 19e.28: W 72 - W 86 |
B 97: The upper right corner seems to remain as the only place on the board where White could lose some additional points of territory. So what about a move on 98 instead ? [ see variation ] |
Dia. 19e.29: B 87 - B 99 |
Dia. 19e.30: W 100 - W 112 |
|
|
Dia. 19e.31: B 113 - W 124 |
B 127: It is not possible for Black to interrupt the sequence on the left side and to play (for example) this move in the lower right corner, hoping for an additional 1-point advantage. [ see variation ] |
Dia. 19e.32: B 125 - W 132 |
W 134: White could follow the sequence in the Weiqi FaYangLun with an Atari in the upper left. [ see variation] |
Dia. 19e.33: B 133 - W 134 |
|
Dia. 19e.34: B 135 |
W 136: This is the last possible moment to start a Semeai in the upper right. [ see variation ] |
Dia. 19e.35: W 136 - W 142 |
|
Dia. 19e.36: B 143 - W 152 |
|
Dia. 19e.37: B 153 - W 162 |
|
Dia. 19e.38: B 163 - B 171 |
Black has captured one additional White stone on the marked point, what more than compensates for the loss of that one Black stone for the second Throw-in. | Dia. 19e.39: "The End here" |
So Black was able to narrow the gap a little bit. White wins by one point. Because this variation is one point better for Black than the Main Path, I would be very interested in getting knowledge of the Semeai mentioned in the sources, which ends in Black's defeat. |
Dia. 19e.40: "The Score" |
W 26: So White tries the variation that starts with taking the two Black stones in the corner. B 29: Please remember that following the Main Path here and playing this move one point to the left is much faster for Black. We will use the following sequence to show something that might have an effect on other sequences, too. |
Dia. 19e.17: W 26 - B 29 |
Dia. 19e.18: W 30 - W 40 |
|
Dia. 19e.19: B 41 - B 51 |
|
Dia. 19e.20: W 52 - W 62 |
|
W 64: As usual White cannot hope on a Ko with 65. |
Dia. 19e.21: B 63 - B 73 |
W 74: This move in the upper right (instead of 81) starts the Semeai variation here. |
Dia. 19e.22: W 74 - B 83 |
Dia. 19e.23: W 84 - B 95 |
|
Dia. 19e.24: W 96 - W 106 |
|
|
Dia. 19e.25: B 107 - B 117 |
W 120: White is successful and wins the Semeai by one move. |
Dia. 19e.26: W 118 - W 120 |
B 121: But Black closes the upper left corner and wins the game either. All the White stones on the left side are dead. It seems to me that this move had not been recognised so far. Even if White would be successful in the variation for White 70 in the Main Path - without the second Throw-in with Black 19 - in winning the Semeai in the upper right, she would lose the game by this move, too. |
Dia. 19e.27: B 121 |
B 97: This Hasami-Tsuke seems to be an obvious alternative at this moment to reduce the White upper right corner. In my opinion there must be a reason why it is not mentioned in the published sources. Joachim Meinhardt was so kind to help me with the following sequences and the commentary. Update 2011: The Hasami-Tsuke is only possible, when Black has played the Guzumi on the marked point in the upper right before. |
Dia. 19n.1: B 97 |
W 100: Prevents further Black actions in this area. |
Dia. 19n.2: W 98 - B 107 |
Dia. 19n.3: W 108 - B 117 |
|
|
Dia. 19n.4: W 118 - W 124 |
W 128: White must force Black to answer the question "To connect or not to connect ?" before she takes the chain of Black stones in the centre off the board. Otherwise she will give opportunities to Black to turn the tables. B 129: It is not possible for Black to connect his stone in Atari with a move at 130. [ see variation ] B 131: The following sequence is equivalent to that of the Main Path. |
Dia. 19n.5: B 125 - W 134 |
|
Dia. 19n.6: B 135 - W 136 |
|
Dia. 19n.7: B 137 |
|
Dia. 19n.8: W 138 - W 144 |
|
Dia. 19n.9: B 145 - W 154 |
|
Dia. 19n.10: B 155 - W 164 |
|
Dia. 19n.11: B 165 - B 169 |
|
Dia. 19n.12: W 170 - B 173 |
All Black efforts in the top right corner had no effect on the final result. As before, White has seven points in the marked area, including the captured Black stone. | Dia. 19n.13: "The End here" |
So Black was able to narrow the gap a little bit. White wins by one point. Because this variation is one point better for Black than the Main Path, I would be very interested in getting knowledge of the Semeai mentioned in the sources, which ends in Black's defeat. |
Dia. 19n.14: "The Score" |
B 127: At any moment (except for such Eye stealing moves like 125 here) after having completed the four-stone-formation inside White's Eye on the left side (with 93), Black (mistakenly) could have the idea to play at the 3-2-point of the lower right corner. That is because in every variation analysed so far Black would play at this point after White captured the twenty Black stones in the centre. |
Dia. 19o.1: B 125 - B 127 |
W 128: White follows the Main Path for the time being. She cannot answer inside the Seki in the lower right, as this would make it possible for Black to resolve it. Capturing the twenty Black centre stones now loses the game, too. |
Dia. 19o.2: W 128 - W 136 |
W 138: White simply continues to take Black liberties in the upper right. Capturing the Black stones in the centre (as "usual") would be not correct here. [ see variation ] B 139: Black cannot capture the three White stones, because his earlier played marked stone took his centre group a liberty. [ see variation ] W 140: Now it is the right moment to capture the Black centre group. |
Dia. 19o.3: B 137 - W 140 |
W 142: White does not make the Placement now, but continues to occupy liberties of the Black group in the upper right. |
Dia. 19o.4: B 141 - W 144 |
Dia. 19o.5: B 145 - B 149 |
|
W 152: Black is that one move too late, he had lost in the beginning by playing in the lower right instead of continuing the "usual" sequence on the left side. |
Dia. 19o.6: W 150 - W 152 |
White wins the game. | Dia. 19o.7: "The End here" |
W 138: Capturing the twenty Black centre stones is a little bit too early. |
Dia. 19o.8: W 138 |
Dia. 19o.9: B 139 |
|
W 140: It is best for White to start with the Tsuke of Yamada Shinji in the upper right. This time she does not make the Placement inside the four stones Black captured with 139, but keeps it in reserve. Because Black already has the marked stone (= 127) in place, a White placement would be Gote. |
Dia. 19o.10: W 140 - W 150 |
B 159: Black must be careful here. It is not correct to follow the known path of the "usual" Endgame on the left side. [ see variation ] |
Dia. 19o.11: B 151 - W 160 |
Dia. 19o.12: B 161 - B 169 |
|
Dia. 19o.13: W 170 - B 173 |
|
Dia. 19o.14: "The End here" |
|
White's mistake had cost her the game, but Black will not win either. A 1-point advantage compared to the main variation after the second Throw-in is not enough to turn the tables. JIGO. |
Dia. 19o.15: "The Score" |
Dia. 93p.1: B 93 - W 100 |
B 93: An idea of mine, coming into my mind during the discussions with Joachim Meinhardt. As stated in the "Questions" section (please refer to page 21), Black denies White from getting three points of territory here without hurting the number of liberties of his group. W 94, 96, 98: Capturing the Ko on the left side could result in a "life-life" situation, where both the White group on the left and the Black group in the upper right live. What we do not know with certainty is, 1.: if this Ko capture would be an option for White to win the game and 2.: - in addition - if White could afford not to resolve the Ko on the left with a second move there. I am in fear that finding the answers will be a bit too advanced for someone on Amateur Kyu level. For some results of our research: [ see variation ] B 99: Black connects on the left, because playing at 100 would be Gote. W 100: Now the question arises, if White will be able to keep the two marked points as territory, reducing the advantage of the Black move at 93 to one point. To allow Black to play at this point would result in a 2-point loss for White. |
Dia. 93p.2: B 101 - W 112 |
B 101: But as a matter of course Black wants more. W 102: Blocking solidly at 102 seems best for White. Other options would be cutting at 104 [ see variation ] or connecting at 103 [ see variation ]. |
Dia. 93p.3: B 113 - W 122 |
|
Dia. 93p.4: B 123 - W 128 |
|
Dia. 93p.5: B 129 - W 136 |
|
Dia. 93p.6: B 137 - W 138 |
|
Dia. 93p.7: B 139 |
|
Dia. 93p.8: W 140 - W 146 |
W 140: The Black group in the upper right has seven liberties, so trying to start a Semeai there will be in vain. |
Dia. 93p.9: B 147 - W 156 |
|
Dia. 93p.10: B 157 - W 166 |
|
Dia. 93p.11: B 167 - B 175 |
|
Dia. 93p.12: "The End here" |
|
Dia. 93p.13: "The Score" |
Black wins by 1 point. |