EVENT WHITE Iwamoto, 8p BLACK Ohashi, 1p RESULT B+2 BOARDSIZE 19 KOMI 0.5 SOURCE Source BGJ 12, August 1970, Page 12 ANALYSIS Iwamoto SETUP B D4 Q4 D10 Q10 D16 Q16 COM Copyright British Go Association 1970, 2000 ENDCOM W 1 R14 B 2 N17 W 3 Q7 B 4 O4 W 5 F3 B 6 D6 W 7 L3 B 8 O6 MARK D@R3 L3 C@N5 B@M3 A@R16 COM Black 8: Rather weak. A would have been better. Had white 7' been at B, there would have been a threat that white would follow up with C or 56(D). As it stands, there is little immediate danger. ENDCOM VAR B 1 R16 ENDVAR W 9 O7 B 10 N6 W 11 O10 B 12 Q13 MARK D@P12 A@R16 COM Black 12: Black should first protect the corner at A, but if he wishes to save the marked stone he should play at D, so as not to force the play in the unprotected top corner. After 12, the sequence played to 16 is natural. ENDCOM W 13 Q14 B 14 P13 W 15 P14 B 16 O13 W 17 R12 MARK A@S12 H@S13 G@R13 F@R17 E@S16 COM White 17; Too early. E was better. This would be answered with black 25(F), white 17. Then if black 18(G), white 19(H) and black cannot cut at 20(A). See variation. ENDCOM VAR W 1 S16 B 2 R17 W 3 R12 B 4 R13 W 5 S13 MARK S13 R13 R12 R17 S16 A@S12 ENDVAR B 18 R13 W 19 S13 B 20 S12 MARK A@P11 I@O14 H@S15 G@T12 F@S14 E@S11 COM Black 20: Should White answer with 24(E), then Black will cut on the other side with F, white 23(G) captures, black 21(H), white 28(I) or 47(A) but he is in difficulty. See variation. ENDCOM VAR B 1 S12 W 2 S11 B 3 S14 W 4 T12 B 5 S15 W 6 O14 MARK A@P11 O14 S15 T12 S14 S11 1@S12 ENDVAR W 21 S15 B 22 R11 MARK G@T13 COM Black 22: No. he must play G. The comment applies to all such situations; the fear of ko is groundless, but common. ENDCOM W 23 T12 B 24 S11 W 25 R17 B 26 Q17 W 27 R18 B 28 O14 W 29 G17 MARK I@G16 H@S4 COM White 29: White might have played at H, but then black could have answered at I, which is very large. ENDCOM VAR W 1 S4 B 2 G16 ENDVAR B 30 H3 COM Black 30: Good. White is in trouble. ENDCOM W 31 E5 MARK A@C3 COM White 31: If he played at 37(A) instead, the sequence to 7 in the variation makes white safe in the corner, but then Black can play 8 which is not good for white. ENDCOM VAR W 1 C3 B 2 D3 W 3 D2 B 4 E2 W 5 C2 B 6 E3 W 7 B5 B 8 K4 MARK K4 B5 E3 C2 E2 D2 D3 C3 ENDVAR B 32 D5 W 33 J4 B 34 G4 COM Black 34: Good. ENDCOM W 35 D3 B 36 G6 W 37 C3 B 38 E4 MARK A@K6 COM Black 38: Safe, but a bit weak. Black could have played at 45(A) to threaten the White stones below. ENDCOM W 39 G2 B 40 H2 W 41 K7 B 42 N7 W 43 O8 B 44 J6 W 45 K6 B 46 M8 MARK A@K9 COM Black 46: The jump to 52(A) would have been proper, but in a six stone game 46 is acceptable as it makes for easier play for Black. ENDCOM VAR B 1 K9 ENDVAR W 47 P11 B 48 Q11 W 49 J7 B 50 H6 W 51 M11 B 52 K9 W 53 M5 B 54 K11 W 55 R4 B 56 R3 MARK A@R5 COM Black 56: Weak. It would have been better to play the sequence in the variation. ENDCOM VAR B 1 R5 W 2 Q5 B 3 Q6 W 4 R6 B 5 P5 W 6 S5 B 7 Q5 W 8 S7 B 9 R3 MARK R3 S7 S5 P5 R6 Q6 Q5 R5 ENDVAR W 57 Q5 B 58 Q3 W 59 S5 B 60 H8 W 61 J9 B 62 J8 W 63 N3 B 64 O3 W 65 K2 COM White 65: White is now alive, but black outside strength has increased. The situation is still difficult for White. ENDCOM B 66 K8 MARK B@R6 A@S3 COM Black 66: Unnecessary. Better was 67(A), or better still the variation from B to threaten the whole white group. ENDCOM VAR B 1 R6 W 2 Q6 B 3 S3 MARK S3 Q6 R6 ENDVAR W 67 S3 B 68 K17 MARK J@J17 COM Black 68; Black could have played at J. His position is very solid and he can afford to play very strongly. ENDCOM W 69 C13 B 70 E15 MARK A@E17 COM Black 70: No. This invites white into the corner. The correct play was the variation. ENDCOM VAR B 1 E17 W 2 G15 B 3 E14 MARK E14 G15 E17 ENDVAR W 71 K16 B 72 L17 W 73 C17 B 74 C16 W 75 D17 B 76 C11 W 77 E13 B 78 B17 W 79 E17 B 80 G15 W 81 G13 B 82 J15 W 83 J13 B 84 J16 W 85 B18 B 86 B16 MARK A@E11 COM Black 86: Weak, he should have played at 87(A) to attack the white chain ENDCOM W 87 E11 B 88 K13 MARK L@F11 A@E10 COM Black 88: Better to have played 91(A), then if white L, black 88. ENDCOM VAR B 1 E10 W 2 F11 B 3 K13 ENDVAR W 89 J12 B 90 K12 W 91 E10 B 92 D9 W 93 C12 B 94 D11 W 95 D12 B 96 B11 W 97 H10 COM White 97: Now white is safe here, but black is still ahead in points. ENDCOM B 98 B4 W 99 B3 B 100 E9 W 101 F9 B 102 F8 W 103 G9 B 104 G8 MARK A@N2 COM Black 104: Weak. The variation would have kept sente, and gained about 7 points for Black. ENDCOM VAR B 1 N2 W 2 M2 B 3 N4 W 4 M3 B 5 O2 MARK O2 M3 N4 M2 N2 COM [I don't see how this variation keeps sente. sgb] ENDCOM ENDVAR W 105 N2 B 106 Q18 W 107 Q19 B 108 P19 W 109 R19 B 110 O18 W 111 J18 B 112 K18 W 113 B5 B 114 C4 W 115 A4 B 116 B6 W 117 A6 B 118 C5 W 119 A5 B 120 A7 W 121 A3 B 122 B7 W 123 P15 B 124 O16 W 125 S8 MARK A@S6 COM White 125: Big; it prevents A, a sente play worth 6 or 7 points. ENDCOM B 126 P9 W 127 O9 B 128 P6 W 129 Q8 B 130 A18 W 131 B19 B 132 G16 MARK B@H18 COM Black 132: Black can't play at B instead, because of the variation, cutting off six black stones ENDCOM VAR B 1 H18 W 2 G18 B 3 H17 W 4 F15 MARK F15 H17 G18 H18 ENDVAR W 133 H17 B 134 N12 W 135 L10 B 136 Q6 W 137 R6 B 138 S2 W 139 T2 B 140 S1 W 141 P2 B 142 O2 W 143 O1 B 144 P5 W 145 R5 B 146 R16 W 147 S16 B 148 J3 W 149 K4 B 150 B14 W 151 B13 B 152 C14 W 153 Q2 B 154 R2 W 155 M12 B 156 M13 COM The record breaks off at move 156. Black won by two points. ENDCOM