invalid problem set
Problem 21986
Created 2018-06-30
Name Q18 第å八番
Source Original (オリジナル)
Rating
Difficulty 7 dan
Average Solve Time 98 secs
User Attempts
11 / 77
Solve Ratio Rating 2 dan
rating history
18. Ko problem (黒先劫).
Please note that two step ko adavantageous for white is NOT correct. Please seek for real Ko.
Difficulty level 2 at mimura15.jp
(;AB[bn]AB[bm]AB[co]AB[do]AB[eo]AB[gp]AB[gq]AB[gr]AB[ir]AW[cq]AW[er]AW[bs]AP[goproblems]
(;B[dq];W[dr]
(;B[bq];W[bp]
(;B[cp];W[cr]
(;B[ar];W[br];B[ap]C[RIGHT])
(;B[ap];W[ar])
(;B[bo];W[ar]))
(;B[cr];W[cp];B[br];W[ar]
(;B[aq];W[cs];B[as];W[ds])
(;B[cs];W[aq];B[as];W[ap])))
(;B[aq];W[bp];B[ap];W[ao];B[bo];W[ar])
(;B[ar];W[bp];B[ap];W[ao];B[br];W[cr];B[bq];W[aq])
(;B[br];W[cr])
(;B[cr];W[bq]))
(;B[aq];W[bp];B[ap];W[ao];B[bo];W[ar])
(;B[ar];W[bp]
(;B[ap];W[ao];B[br];W[cr];B[bq];W[aq])
(;B[dq];W[dr];B[ap];W[ao];B[br];W[cr];B[bq];W[aq])
(;B[es];W[ds]
(;B[ap];W[ao];B[br];W[cr];B[bq];W[aq])
(;B[dq];W[dr];B[ap];W[ao];B[br];W[cr];B[bq];W[aq])))
(;B[bq];W[bp])
(;B[bp];W[bq])
(;B[cr];W[bq]
(;B[br];W[ar];B[cs];W[dr];B[as];W[ds];B[aq];W[bp]
(;B[bo];W[ap];B[dq];W[ar])
(;B[ao];W[ap];B[dq];W[ar])
(;B[dq];W[eq];B[dp];W[ap];B[bo];W[ar]))
(;B[dr];W[dq];B[es];W[fs]
(;B[eq];W[ds];B[fr];W[es])
(;B[fr];W[ds];B[eq];W[es])))
(;B[br];W[cr])
(;B[es];W[ar]))
Toggle next/previous buttons