Problem 6763 goproblems.com


Author	Haze	Created	2005-06-27
Difficulty	6 dan (history)	Source	Game between Hrasuli and myself on KGS
AVG solve time	65 sec	Stars	2.6 (10 votes)
User attempts	816 / 3004	Collections	N/A
Genre	life and death	Your attempts	N/A
Similar problems
Created	2005-06-27
Source	Game between Hrasuli and myself on KGS
Stars	2.6 (10 votes)
Collections	N/A
Your attempts	N/A

(;AB[ja]AB[jc]AB[kb]AB[ka]AB[lb]AB[la]AB[kc]AB[ld]AB[kd]AB[jd]AB[id]AB[ke]AB[ie]AB[if]AB[jf]AB[hf]AB[gf]AB[ge]AB[gd]AB[fd]AB[fc]AB[ee]AB[de]AB[dd]AB[df]AB[dg]AB[dh]AB[cf]AB[hh]AW[kf]AW[kg]AW[jg]AW[ig]AW[jh]AW[lh]AW[le]AW[me]AW[md]AW[fe]AW[ia]AW[jb]AW[ic]AW[hb]AW[hc]AW[hd]AW[he]AW[gc]AW[fb]AW[ec]AW[dc]AW[ed]AW[cd]AW[ce]AW[bf]AW[cg]AW[bg]AW[ch]AB[hg]AW[mb]AW[ma]AW[mc]AW[ib]C[White has made the mistake of answering the endgame move K17 with J18. Black to punish white.]AB[be]LB[jc:1]LB[ib:2]AP[goproblems] (;B[ha];W[ga]C[That acomplishes nothing.]) (;B[gb];W[ga]C[That acomplishes nothing.]) (;B[bd];W[cc]C[Nothing more for black to do here.]) (;B[cc] (;W[bd] (;B[bc];W[ae] (;B[db];W[eb] (;B[ga];W[gb] (;B[da];W[bb] (;B[cb];W[ac] (;B[ea]C[Starting at C17 might trick white into trying to save the C16 stones, allowing black to go for the larger group.RIGHT]) (;B[fa]C[Starting at C17 might trick white into trying to save the C16 stones, allowing black to go for the larger group.RIGHT]) (;B[ca];W[ba]) (;B[ba];W[ab] (;B[ea]C[Starting at C17 might trick white into trying to save the C16 stones, allowing black to go for the larger group.RIGHT]) (;B[fa]C[Correct. In this sequence, white can make a ko for B19.]))) (;B[ab];W[cb];B[ac];W[ad]) (;B[ac];W[cb]) (;B[ea];W[cb]) (;B[fa];W[cb])) (;B[ea];W[cb]C[White lives.]) (;B[ca];W[ac] (;B[bb];W[ab] (;B[ea];W[ba];B[aa]MA[ba]C[Ko. This is bad.]) (;B[da];W[ba];B[aa]MA[ba]C[Ko. This is bad.]) (;B[ba];W[ea] (;B[fa]C[Black wins the semeai without ko. Thanks to sestir for this solution!RIGHT];W[ad];B[da]) (;B[aa];W[ad] (;B[fa]C[Seki]) (;B[ha]C[Seki.])) (;B[da]C[Black wins the semeai without ko. Thanks to sestir for this solution!RIGHT]) (;B[ha]C[Black wins the semeai without ko. Thanks to sestir for this solution!RIGHT])) (;B[aa];W[ba]C[Ko.])) (;B[cb];W[ea]C[Black will not be able to approach.]) (;B[ea];W[bb]C[White lives.]) (;B[da];W[bb]C[White lives.])) (;B[cb]C[];W[da] (;B[ca];W[fa]C[This is ko. Black is able to kill unconditionally after wD19.]) (;B[fa];W[ac] (;B[ea];W[ha] (;B[ea];W[fa];B[ca]C[Ko, black could have killed unconditionally in this variation.RIGHT]) (;B[ca];W[fa]C[Ko, black could have killed unconditionally in this variation.RIGHT])) (;B[ca];W[ba];B[ea];W[bb];B[ha];W[ab]C[Thanks to JottKa for this variation.RIGHT])))) (;B[ea];W[cb]) (;B[da] (;W[bb] (;B[cb];W[ac] (;B[ga];W[fa]) (;B[fa];W[ga]) (;B[ba];W[ab] (;B[fa];W[ga]) (;B[ga];W[fa]))) (;B[ea];W[cb];B[ga];W[gb]) (;B[ga] (;W[fa] (;B[ea]C[Starting at C17 might trick white into trying to save the C16 stones, allowing black to go for the larger group.RIGHT]) (;B[gb];W[ha];B[ga];W[cb];B[gb];W[ac]C[You could have done better by playing E19 instead of G18 when G18 was first played.])) (;W[cb];B[gb];W[ca]C[RIGHT])) (;B[fa];W[cb])) (;W[ga] (;B[bb] (;W[ba] (;B[ac];W[ea]) (;B[ca];W[ea];B[aa]C[RIGHT])) (;W[ac];B[ab];W[ea] (;B[ba]C[RIGHT]) (;B[ca]C[RIGHT])) (;W[ea];B[ba])) (;B[ba] (;W[ab];B[ac];W[bb];B[cb]) (;W[ac];B[ab];W[ea] (;B[cb];W[ad]C[RIGHT]) (;B[bb]C[RIGHT]) (;B[ca]C[RIGHT]))) (;B[ab];W[ba] (;B[bb];W[ca]) (;B[ca];W[ea];B[cb]))))) (;B[ga];W[fa] (;B[gb];W[ha] (;B[ga];W[gb];B[db];W[eb] (;B[da]C[Correct. Starting at C17 might trick white into trying to save the C16 stones, allowing black to go for the larger group.RIGHT];W[bb] (;B[cb];W[ac]C[White lives. Black cannot approach.]) (;B[ea];W[ac];B[ga]C[Starting at C17 might trick white into trying to save the C16 stones, allowing black to go for the larger group.RIGHT])) (;B[cb];W[ac] (;B[ab];W[ba] (;B[ca];W[ad]C[ko]) (;B[ad]C[ko]) (;B[da];W[bb]C[ko])) (;B[ba];W[ab];B[da];W[bb]) (;B[da];W[bb]) (;B[ca]C[ko])) (;B[ca];W[ac];B[bb];W[ab];B[ba]C[From here it can be either a ko or seki. Black can do better.])) (;B[gb];W[ga];B[db];W[eb] (;B[da]C[Correct.];W[bb] (;B[ea]C[Starting at C17 might trick white into trying to save the C16 stones, allowing black to go for the larger group.RIGHT]) (;B[cb];W[ac]C[White lives.];B[ba];W[ab])) (;B[ca];W[bb] (;B[ea];W[da];B[cb];W[ac];B[ea]MA[da]C[Black can do better than ko.]) (;B[cb];W[ac];B[ea];W[da]MA[ea]C[Black can do better than ko.])) (;B[cb];W[ac] (;B[ab];W[ba];B[da];W[bb]C[Ko.]) (;B[ba];W[ab];B[da];W[bb]) (;B[da];W[bb];B[ba];W[ab]) (;B[ca]C[Ko.]))) (;B[db];W[eb] (;B[da];W[bb] (;B[cb];W[ac]C[White lives. Black cannot approach.]) (;B[ea];W[cb];B[gb];W[ca];B[ga]C[Starting at C17 might trick white into trying to save the C16 stones, allowing black to go for the larger group.RIGHT]) (;B[gb];W[cb];B[ga];W[ac]C[Starting at C17 might trick white into trying to save the C16 stones, allowing black to go for the larger group.RIGHT])) (;B[gb];W[cb];B[ga];W[da]C[Starting at C17 might trick white into trying to save the C16 stones, allowing black to go for the larger group.RIGHT]) (;B[ga];W[gb];B[da];W[bb] (;B[cb];W[ac]C[White lives. Black cannot approach.]) (;B[ea];W[ac];B[ga]C[Starting at C17 might trick white into trying to save the C16 stones, allowing black to go for the larger group.RIGHT])))) (;B[db];W[eb] (;B[da]C[RIGHT];W[bb];B[ea]C[RIGHT]) (;B[ca]C[At best, this leads to ko.])) (;B[ha];W[gb];B[db];W[eb];B[da];W[bb] (;B[cb];W[ac]) (;B[ac];W[cb])) (;B[da];W[db];B[cb];W[eb];B[ca]C[RIGHT])) (;B[da] (;W[ga] (;B[eb]C[RIGHT]) (;B[db];W[eb] (;B[bb] (;W[ba] (;B[ac];W[ea]) (;B[ca];W[ea];B[aa]C[RIGHT])) (;W[ac];B[ab];W[ea] (;B[ba]C[RIGHT]) (;B[ca]C[RIGHT])) (;W[ea];B[ba])) (;B[ba] (;W[ab];B[ac];W[bb];B[cb]) (;W[ac];B[ab];W[ea] (;B[cb];W[ad]C[RIGHT]) (;B[bb]C[RIGHT]) (;B[ca]C[RIGHT]))) (;B[ab];W[ba] (;B[bb];W[ca]) (;B[ca];W[ea];B[cb])))) (;W[ea];B[db];W[eb];B[ga] (;W[cb];B[gb];W[ca]C[Black can play H19 later.RIGHT]) (;W[gb] (;B[fa]C[RIGHT]) (;B[ha]C[RIGHT]) (;B[bb]C[RIGHT]) (;B[cb]C[RIGHT]) (;B[ba] (;W[cb];B[ca];W[ac];B[bb];W[ab]C[Black can ignore this move.RIGHT]) (;W[ab];B[bb];W[ac]C[Black can ignore this move.RIGHT]))))) (;B[eb];W[db] (;B[ga];W[gb];B[cb];W[da]) (;B[da] (;W[cb];B[fa];W[ea]C[Black can do better than ko.]) (;W[ea];B[cb];W[ca];B[ba];W[da];B[ab];W[ac]C[Ko, black takes first, black has a local threat of G19.])))) (;B[db];W[eb] (;B[bc];W[ae] (;B[da];W[ga] (;B[bb] (;W[ba] (;B[ac];W[ea]) (;B[ca];W[ea];B[aa]C[RIGHT])) (;W[ac];B[ab];W[ea] (;B[ba]C[RIGHT]) (;B[ca]C[RIGHT])) (;W[ea];B[ba])) (;B[ba] (;W[ab];B[ac];W[bb];B[cb]) (;W[ac];B[ab];W[ea] (;B[cb];W[ad]C[RIGHT]) (;B[bb]C[RIGHT]) (;B[ca]C[RIGHT]))) (;B[ab];W[ba] (;B[bb];W[ca]) (;B[ca];W[ea];B[cb]))) (;B[ga];W[cb];B[gb];W[da]C[RIGHT])) (;B[da];W[cb];B[bc];W[ca] (;B[bb];W[ea];B[ad]C[RIGHT]) (;B[ad]C[RIGHT]) (;B[ga] (;W[ea];B[ad]C[RIGHT]) (;W[ae];B[gb];W[ea]C[RIGHT]))) (;B[ga] (;W[gb] (;B[bc] (;W[ae] (;B[da]C[RIGHT];W[bb] (;B[cb];W[ac] (;B[ea]C[Starting at C17 might trick white into trying to save the C16 stones, allowing black to go for the larger group.RIGHT]) (;B[fa]C[Starting at C17 might trick white into trying to save the C16 stones, allowing black to go for the larger group.RIGHT]) (;B[ca];W[ba]) (;B[ba];W[ab] (;B[ea]C[Starting at C17 might trick white into trying to save the C16 stones, allowing black to go for the larger group.RIGHT]) (;B[fa]C[Correct. In this sequence, white can make a ko for B19.]))) (;B[ab];W[cb];B[ac];W[ad]) (;B[ac];W[cb]) (;B[ea];W[cb]) (;B[fa];W[cb])) (;B[cb]C[Another new variation, added thanks to JottKa and LCZLAPINSKI.RIGHT];W[da] (;B[ca];W[fa]C[This is ko. Black is able to kill unconditionally after wD19.]) (;B[fa];W[ac] (;B[ea];W[ha] (;B[ea];W[fa];B[ca]C[Ko, black could have killed unconditionally in this variation.RIGHT]) (;B[ca];W[fa]C[Ko, black could have killed unconditionally in this variation.RIGHT])) (;B[ca];W[ba];B[ea];W[bb];B[ha];W[ab]C[Thanks to JottKa for this variation.RIGHT])))) (;W[cb] (;B[bb];W[da];B[ad]C[RIGHT]) (;B[ad]C[RIGHT]))) (;B[cb]C[Thanks to LCZLAPINSKI for this variation.RIGHT])) (;W[fa];B[bc] (;W[ae];B[da];W[bb] (;B[ea]C[RIGHT]) (;B[cb];W[ac]) (;B[gb];W[ha];B[ga];W[cb];B[gb];W[ac]C[Black could have done better in this sequence.RIGHT])) (;W[cb] (;B[ad]C[RIGHT]) (;B[bb];W[da];B[ad]C[RIGHT]))))) (;B[eb];W[db];B[ga];W[gb];B[bc];W[ae];B[cb];W[da])) (;W[cb] (;B[bd]C[Correct. With proper white play, the best that black should get is the C16 group.RIGHT]) (;B[bc]C[Correct. With proper white play, the best that black should get is the C16 group.RIGHT]) (;B[ga];W[gb] (;B[eb];W[db] (;B[ea];W[da] (;B[bc]C[Correct. With proper white play, the best that black should get is the C16 group.RIGHT]) (;B[bd]C[Correct. With proper white play, the best that black should get is the C16 group.RIGHT]) (;B[fa];W[ha] (;B[bc]C[Correct. With proper white play, the best that black should get is the C16 group.RIGHT]) (;B[bd]C[Correct. With proper white play, the best that black should get is the C16 group.RIGHT])) (;B[ha];W[fa] (;B[bc]C[Correct. With proper white play, the best that black should get is the C16 group.RIGHT]) (;B[bd]C[Correct. With proper white play, the best that black should get is the C16 group.RIGHT]))) (;B[bd]C[Correct. With proper white play, the best that black should get is the C16 group.RIGHT]) (;B[bc]C[Correct. With proper white play, the best that black should get is the C16 group.RIGHT])) (;B[bc]C[Correct. With proper white play, the best that black should get is the C16 group.RIGHT]) (;B[bd]C[Correct. With proper white play, the best that black should get is the C16 group.RIGHT])) (;B[db];W[bc];B[eb];W[cc] (;B[fa];W[ga]C[Ko.]) (;B[ga];W[fa])) (;B[eb] (;W[bc];B[ga];W[fa] (;B[ea]C[RIGHT]) (;B[gb];W[ha] (;B[ga];W[gb];B[ea]C[RIGHT]) (;B[gb];W[db];B[ga];W[ea]C[RIGHT]))) (;W[db] (;B[bc]C[RIGHT]) (;B[bd]C[RIGHT]) (;B[ga];W[gb] (;B[bc]C[RIGHT]) (;B[bd]C[RIGHT]) (;B[fa];W[ea] (;B[bc]C[RIGHT]) (;B[bd]C[RIGHT]))))))) (;B[ga] (;W[gb] (;B[cc];W[db] (;B[bd]C[Good. Black can get a bit more before playing B16 though.RIGHT]) (;B[cb]C[Correct. Thanks to LCZLAPINSKI for this variation.RIGHT];W[da]C[Correct. Thanks to LCZLAPINSKI for this variation.RIGHT] (;B[bd]C[RIGHT]) (;B[ca];W[fa];B[bd]C[RIGHT]) (;B[ea];W[fa];B[ca];W[eb];B[bd]C[Correct, but a ko threat had been wasted with the E19 exchange.RIGHT]))) (;B[db];W[eb];B[cc];W[cb] (;B[bc]C[Correct. All black should be able to get away with is the capture of the C16 stones.RIGHT]) (;B[bd]C[Correct. All black should be able to get away with is the capture of the C16 stones.RIGHT])) (;B[eb];W[db];B[cc];W[bd];B[da] (;W[cb];B[fa];W[ea]C[Ko, black can do better.]) (;W[ea];B[bc];W[ae];B[cb];W[ca];B[ba];W[ac];B[da]C[Ko, Black can do better.]))) (;W[fa] (;B[gb];W[ha] (;B[ga];W[gb];B[cc];W[bd] (;B[bc];W[ae];B[db];W[eb];B[da] (;W[bb] (;B[ea]C[If white makes the mistake of saving her C16 group, black can get much more.RIGHT];W[ac];B[ga]C[Starting at C17 might trick white into trying to save the C16 stones, allowing black to go for the larger group.RIGHT]) (;B[cb];W[ac]C[Black cannot approach.])) (;W[cb];B[bb]C[RIGHT])) (;B[db];W[eb];B[bc];W[ae];B[da]C[If white makes the mistake of saving her C16 group, black can get much more.RIGHT];W[bb] (;B[cb];W[ac]C[White lives. Black cannot approach.]) (;B[ea];W[ac];B[ga]C[Starting at C17 might trick white into trying to save the C16 stones, allowing black to go for the larger group.RIGHT]))) (;B[gb];W[cc];B[ga]C[RIGHT];W[eb]C[If white makes the mistake of saving her C16 group, black can get much more.])) (;B[cc] (;W[bd] (;B[bc];W[ae];B[db];W[eb];B[da];W[bb];B[ea]C[RIGHT]) (;B[db];W[eb];B[bc] (;W[ae];B[da]C[RIGHT];W[bb];B[ea]C[RIGHT]) (;W[cb];B[bb];W[da];B[ad]C[Correct. Thanks to LCZLAPINSKI for this variation.RIGHT]))) (;W[cb] (;B[bc]C[RIGHT]) (;B[bd]C[RIGHT]))))) (;B[cb];W[cc]C[White saves everything.]) (;B[db];W[cc]C[White saves everything.]) (;B[eb];W[db];B[ga];W[gb] (;B[fa];W[ea]) (;B[cc];W[bd];B[bc];W[ae];B[cb];W[da])))