P.Olsson (Sweden) vs Louise O'Callaghan

British Go Journal No. 40. [1] February 1978. Page 16.

A 3rd round struggle between a 2-kyu, Black, and a 3-kyu, which has more than its fair share of excitement, mistakes and instructive points. Black blunders horribly, fights hard to recover, but has the stuffing knocked out of him when his own area is successfully invaded.

Black: P.Olsson (Sweden), 2k
White: Louise O'Callaghan, 3k
The game-file in SGF [2] format.

Figure 1 (1-100)

• White 8 is reasonable, though not joseki - after 9-10 have been exchanged White 8 should be one point further from the 2-stone wall.
• Black 11 should be one point higher - playing here is just too far away to have much effect on White. Of course, Black 11 is not affected by White either, but this is a small gain for Black, since Black 11 is backed up by Black 3 & 5. It is White whose stones are weak.
• 13-21 is a standard sequence when black has a stone such as Black 5 on the right. The large moyo created is Black's compensation for having pushed White along the 4th line with 15 and 19 - a course which would normally be taboo.
• The knight's move between 20, 22 is a weakness White would have avoided by playing 22 just above 19. Either way Black 23 is natural before White gets another stone in this area and makes invasion very difficult. White 24 goes for a maximum area anyway. By diving in at 25, Black does not have to defend a weak group outside and he gets sente when White plays 36 to roughly connect with White 12. (However, 32 should be just below 30 when White has squeezed with 24 as here.)
• Black 37 leans towards the White group and weakens it, because Black 11 was one point too low, so is this one point too far away, and White ignores it to play 38. This has the advantage of increasing white's moyo and decreasing black's prospects.
• Black 39 is another slow move, but now the white group must move and 40 is a simple way to run out. White's fear is that black will run out slightly ahead of him towards the centre and end up by devastating the one giant White area. So White gets ahead in a loose way with the two-point jump to 42, but of course this can be cut sooner or later. Maybe 44 was White's chance to strengthen her group, in preparation for an invasion of Black's moyo.
• With 44 White seems to actually back off from Black's moyo, as if she were ahead and able to relax. But White has only one territory, while Black has three and is somewhat ahead. At this critical point in the game, White has a choice between pressing Black back, forcing Black to solidify his moyo but preventing him from enlarging it further, or preparing to invade deeply, (see White 132). White 44 here does neither.
• 45-64 is a disaster for White. Black 65 is a fair way to increase his moyo and White 66 is a faint chance for a recovery. The white group should die, but any strength that White can acquire and which faces past 65 to the black moyo all along the bottom gives White a chance of invading. However Black will still win easily if he runs out with 87 etc. far enough to gain liberties, reducing the white moyo as he does so, and then go back and safely capture the dead white group. Black 89 is the blunder that ruins his plan. If he connects to save 91, White can fill any liberty of Black's trapped stones - because White has an eye and Black does not.
• Black 93 is a mistake - if Black should later connect 91 during fighting in the centre, he will threaten nothing. With 97-107 Black is ingeniously attacking both the five White stones, 42-52 etc., and threatening to cut at 108 saving his own stones with a large profit on the edge.

Figure 2 (101-152)

• Black 111 is an excellent point for creating trouble. Black keeps away from the strong white lower left corner and also squeezes the white wall which does not actually have two eyes yet - he only has one eye on the upper edge, in gote. By playing in contact with the white stone, White's possible answers are quite limited.
• The exchange 115-116 is a bonus for Black, see the earlier comment. Black 117 gives Black a small chance of recovery along the edge and removes the same possibility for White. White can cut just above or below 117, but if he does so at once, he loses because of the lack of liberties on the stones 112-114 etc.
• White 124 is an unnecessary sacrifice; it actually helps Black to live so White ends up in gote making herself an eye with 130 and threatening a second eye. However, 130 is a little late - Black could have omitted 129 and pushed left of 107 cutting off the white wall after all.
• Black 131 prevents White playing there, but White at 131 does not kill the black stones and now White can play the invasion that is justified by her 80-86 wall. White 132 is a good point, near enough to the wall to have an excellent chance of joining to it, while also aiming to attach under Black and make a live group along the edge. A move which threatened only one of these objectives will be answered easily. 133 tries to hem white in, so White attaches. Black 135, White 136 helps White live on the edge, but makes it difficult for her to connect. Black 137, White 138 does exactly the opposite.
• Black 139 is ineffective. To stop White making eyes Black should play on the second line, for example at 144, or 146. However, nothing can stop White now, and after 144-148 pushing Black back as far as possible, she joins her wall with 150-152. If Black saves the one stone, White captures 151.

Black resigned - rather to White's suprise. Black was justified, if gentlemanly. The scores are not far apart, but White's territory is almost completely fixed, being mostly dead Black stones. All Black's territories can be reduced. He really has nothing to look forward to.