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Problem | 6712 |
Created | 2005-06-16 |
Source | Various |
Rating | |
Difficulty | 8 dan |
Average Solve Time | 70 secs |
User Attempts |
61 / 1089 |
Solve Ratio Rating | 5 dan |
| rating history |
What is the biggest encroachment into this formation, and how big is it?
Thanks to Spica for the main variations.
(;GM[1]FF[4]CA[UTF-8]AP[CGoban:2]ST[2]
RU[Japanese]SZ[11]KM[0.00]
PW[White]PB[Black]AW[dc][jc][dd][de][ee][fe][ge][he][ie][je][ke][if][kf][hg][jg][gh][kh][fi][gi][hi][ii][ji][ki][fj][kj]
AB[bg][cb][cc][cd][ce][df][ef][ff][gf][fg][ch][eh][bi][ei][ej][gj][hj][ij][jj][ek][gk][hk][ik][jk][kk]LB[da:K][ea:S][fa:L][db:P][eb:I][fk:C]C[No komi, no prisoners yet - Black to win. FORCE]PL[B]
(;B[eb]CR[eb]
;W[fk]CR[fk]
(;B[gb]CR[gb]
;W[db]CR[db]
;B[da]CR[da]
;W[ib]CR[ib]
(;B[fc]CR[fc]
;W[hc]CR[hc]
(;B[hb]CR[hb]
;W[ha]CR[ha]
(;B[ga]CR[ga]
;W[ia]CR[ia]
(;B[gc]CR[gc]
;W[gd]CR[gd]
;B[ec]CR[ec]C[RIGHT You won by 1. 1st move 1 space jump (1sj) was 1 point bigger than saving the 18 point capture, and 2 points bigger than the next
best move. Also, when White does not respond locally to 1sj, the biggest follow-up into this formation is a 2nd 1sj. After W plays J10, F9 is the key
point for both. If W chooses to capture before playing D10, this is the only sequence that allows a B win.])
(;B[ec]CR[ec]
;W[gc]CR[gc]
;B[fd]CR[fd]
;W[gd]CR[gd]C[Jigo (later B must play E/F11).]))
(;B[gc]CR[gc]
;W[ga]CR[ga]
(;B[fa]CR[fa]
;W[ia]CR[ia]
;B[ec]CR[ec]
;W[gd]CR[gd]C[Jigo])
(;B[hd]CR[hd]
;W[ic]CR[ic]
;B[gd]CR[gd]
;W[fa]CR[fa]
;B[ea]CR[ea]
;W[id]CR[id]C[Jigo])))
(;B[ha]CR[ha]
;W[hb]CR[hb]
;B[ia]CR[ia]
;W[ja]CR[ja]
;B[ga]CR[ga]
;W[gc]CR[gc]
(;B[ec]CR[ec]
;W[fd]CR[fd]LB[ea:A][fa:B]C[After B has filled at 'A' or 'B', which he must do when W plays F8, the score is Jigo.])
(;B[fd]CR[fd]C[The best from this is W +1.]))
(;B[gc]CR[gc]
;W[hb]CR[hb]
;B[ec]CR[ec]
;W[ga]CR[ga]
;B[fa]CR[fa]
;W[ha]CR[ha]
;B[gd]CR[gd]
;W[hd]CR[hd]C[Jigo]))
(;B[hb]CR[hb]
;W[fc]CR[fc]
(;B[fb]CR[fb]
;W[hc]CR[hc]
;B[gc]CR[gc]
;W[gd]CR[gd]
;B[ha]CR[ha]
;W[ec]CR[ec]
;B[ia]CR[ia]
;W[ja]CR[ja]C[Jigo])
(;B[hc]CR[hc]
;W[fb]CR[fb]
;B[fa]CR[fa]
;W[ec]CR[ec]
;B[ea]CR[ea]
;W[ic]CR[ic]
(;B[hd]CR[hd]
;W[gd]CR[gd]
;B[ha]CR[ha]
;W[id]CR[id]
;B[ia]CR[ia]
;W[ja]CR[ja]
(;B[ca]CR[ca]C[W +1])
(;B[ga]CR[ga]C[W +1]))
(;B[ha]CR[ha]
;W[hd]CR[hd]
;B[gc]CR[gc]
;W[gd]CR[gd]
(;B[ca]CR[ca]
;W[ia]CR[ia]
;B[ga]CR[ga]C[W +3])
(;B[ga]CR[ga]
;W[ia]CR[ia]
;B[ca]CR[ca]C[W +3]))))
(;B[hc]CR[hc]
;W[fc]CR[fc]
(;B[fb]CR[fb]
;W[hb]CR[hb]
;B[gc]CR[gc]
;W[ic]CR[ic]
(;B[ec]CR[ec]
;W[fd]CR[fd]
(;B[ha]CR[ha]
;W[ia]CR[ia]
;B[ga]CR[ga]
;W[ea]CR[ea]
(;B[fa]CR[fa]
;W[hd]CR[hd]C[Jigo])
(;B[ca]CR[ca]
;W[hd]CR[hd]C[Jigo]))
(;B[hd]CR[hd]
;W[ga]CR[ga]
(;B[id]CR[id]
;W[jd]CR[jd]C[Jigo])
(;B[fa]CR[fa]
;W[ha]CR[ha]
;B[id]CR[id]
;W[jd]CR[jd]C[Jigo])))
(;B[fd]CR[fd]
;W[ec]CR[ec]
;B[gd]CR[gd]
;W[ga]CR[ga]
;B[fa]CR[fa]
;W[ha]CR[ha]
;B[hd]CR[hd]
;W[id]CR[id]
(;B[ca]CR[ca]C[W +1])
(;B[ea]CR[ea]C[W +1]))
(;B[ha]CR[ha]C[The best from this is W +1.]))
(;B[hb]CR[hb]
;W[fb]CR[fb]
(;B[fa]CR[fa]
;W[ec]CR[ec]
;B[ea]CR[ea]
;W[ic]CR[ic]
(;B[hd]CR[hd]
;W[id]CR[id]
;B[gd]CR[gd]
;W[fd]CR[fd]
;B[ha]CR[ha]
;W[ia]CR[ia]
(;B[ca]CR[ca]C[W +1])
(;B[ga]CR[ga]C[W +1]))
(;B[ia]CR[ia]
;W[ja]CR[ja]
;B[ha]CR[ha]
;W[hd]CR[hd]LB[ca:A]C[Please play 'A'. FORCE]
;B[ca]CR[ca]
;W[gc]CR[gc]
;B[ga]CR[ga]C[W +3]))
(;B[ic]CR[ic]
;W[fa]CR[fa]C[B is cut off, and cannot form a live group.]))
(;B[ic]CR[ic]
;W[fb]CR[fb]
;B[fa]CR[fa]
;W[ec]CR[ec]
;B[ea]CR[ea]
;W[gc]CR[gc]
;B[hb]CR[hb]
;W[jb]CR[jb]C[The best from this is W +1.])))
(;B[gc]CR[gc]
;W[db]CR[db]
;B[da]CR[da]
;W[fc]CR[fc]
(;B[fb]CR[fb]
;W[hb]CR[hb]
;B[hc]CR[hc]
;W[ic]CR[ic]
;B[gb]CR[gb]
;W[ha]CR[ha]
;B[ga]CR[ga]
;W[ea]CR[ea]
(;B[fa]CR[fa]
;W[ib]CR[ib]
(;B[ec]CR[ec]
;W[fd]CR[fd]
;B[hd]CR[hd]
;W[id]CR[id]C[Jigo])
(;B[fd]CR[fd]
;W[ec]CR[ec]
;B[gd]CR[gd]
;W[hd]CR[hd]
(;B[ca]CR[ca]C[W +1])
(;B[ea]CR[ea]C[W +1])))
(;B[ca]CR[ca]
;W[ib]CR[ib]
;B[ec]CR[ec]
;W[fd]CR[fd]
;B[hd]CR[hd]
;W[id]CR[id]C[Jigo]))
(;B[gb]CR[gb]
;W[fb]CR[fb]
;B[fa]CR[fa]
;W[ec]CR[ec]
;B[ea]CR[ea]
;W[ib]CR[ib]C[The best from this is W +1.]))
(;B[hb]CR[hb]
;W[db]CR[db]
;B[da]CR[da]
;W[fb]CR[fb]
;B[ec]CR[ec]
;W[fc]CR[fc]
;B[fa]CR[fa]
;W[ed]CR[ed]
;B[gb]CR[gb]
;W[ea]CR[ea]
;B[eb]CR[eb]
;W[ec]CR[ec]
;B[ea]CR[ea]
;W[ib]CR[ib]
;B[hc]CR[hc]
;W[ic]CR[ic]
(;B[hd]CR[hd]
;W[id]CR[id]
;B[gd]CR[gd]
;W[ha]CR[ha]C[W +1])
(;B[gd]CR[gd]
;W[hd]CR[hd]
;B[gc]CR[gc]
;W[ha]CR[ha]C[W +2]))
(;B[ha]CR[ha]
;W[db]CR[db]
;B[da]CR[da]
;W[fb]CR[fb]
(;B[fa]CR[fa]
;W[ec]CR[ec]
;B[ea]CR[ea]
;W[gb]CR[gb]
;B[ga]CR[ga]
;W[ib]CR[ib]
(;B[ia]CR[ia]
;W[ja]CR[ja]
;B[hb]CR[hb]
;W[hc]CR[hc]
;B[ca]CR[ca]C[W +7])
(;B[hb]CR[hb]
;W[hc]CR[hc]
;B[ia]CR[ia]
;W[ja]CR[ja]
;B[ca]CR[ca]C[W +7]))
(;B[ec]CR[ec]
;W[fa]CR[fa]
;B[ea]CR[ea]
;W[fc]CR[fc]
;B[ed]CR[ed]
;W[fd]CR[fd]
;B[ca]CR[ca]C[W +13])
(;B[gb]CR[gb]
;W[ec]CR[ec]
(;B[ea]CR[ea]
;W[fa]CR[fa]
;B[ca]CR[ca]
;W[gc]CR[gc]C[W +16])
(;B[fa]CR[fa]
;W[ea]CR[ea]
;B[ca]CR[ca]
;W[eb]CR[eb]C[W +20 - W took 1st in the ko & B had no threats - actually, B needed 2 big threats, as W had an internal threat at C11.]))))
(;B[fk]CR[fk]
;W[db]CR[db]
;B[da]CR[da]
;W[ea]CR[ea]
;B[ca]CR[ca]
;W[eb]CR[eb]C[Only jigo - 1st move 1sj allows a win by 1.])
(;B[fa]CR[fa]
;W[fk]CR[fk]
(;B[gb]CR[gb]
;W[db]CR[db]
;B[da]CR[da]
;W[eb]CR[eb]
;B[ea]CR[ea]
;W[hc]CR[hc]
(;B[ib]CR[ib]
;W[hb]CR[hb]
;B[ha]CR[ha]
;W[gc]CR[gc]
(;B[ic]CR[ic]
;W[fb]CR[fb]
;B[ga]CR[ga]
;W[id]CR[id]
;B[jb]CR[jb]
;W[kb]CR[kb]
;B[ia]CR[ia]C[W +1])
(;B[fb]CR[fb]
;W[jb]CR[jb]
;B[fc]CR[fc]
;W[ic]CR[ic]
;B[ia]CR[ia]
;W[ja]CR[ja]
;B[ga]CR[ga]
;W[fd]CR[fd]
;B[ec]CR[ec]C[W +1])
(;B[jb]CR[jb]
;W[fb]CR[fb]
;B[ga]CR[ga]
;W[kb]CR[kb]
;B[ic]CR[ic]
;W[id]CR[id]
;B[ia]CR[ia]C[W +1]))
(;B[ia]CR[ia]
;W[hb]CR[hb]
;B[ha]CR[ha]
;W[jb]CR[jb]
(;B[gc]CR[gc]
;W[ja]CR[ja]
(;B[gd]CR[gd]
;W[hd]CR[hd]
;B[fb]CR[fb]
;W[ib]CR[ib]
;B[ga]CR[ga]
;W[fd]CR[fd]
;B[fc]CR[fc]
;W[ec]CR[ec]
;B[ca]CR[ca]C[W +1])
(;B[fb]CR[fb]
;W[gd]CR[gd]
;B[fc]CR[fc]
;W[ib]CR[ib]
;B[ga]CR[ga]
;W[fd]CR[fd]
;B[ec]CR[ec]C[W +1])
(;B[fc]CR[fc]
;W[ib]CR[ib]
;B[ga]CR[ga]
;W[gd]CR[gd]C[W +1]))
(;B[ja]CR[ja]
;W[gc]CR[gc]
(;B[fb]CR[fb]
;W[fc]CR[fc]
;B[ib]CR[ib]
;W[ic]CR[ic]
(;B[ca]CR[ca]
;W[kb]CR[kb]C[W +2])
(;B[ga]CR[ga]
;W[kb]CR[kb]C[W +2]))
(;B[ib]CR[ib]
;W[fb]CR[fb]
;B[ga]CR[ga]
;W[ic]CR[ic]
;B[ka]CR[ka]
;W[kb]CR[kb]
;B[ca]CR[ca]C[W +3])))
(;B[ja]CR[ja]
;W[hb]CR[hb]
;B[ha]CR[ha]
;W[ib]CR[ib]
;B[ia]CR[ia]
;W[gc]CR[gc]
;B[fb]CR[fb]
;W[fc]CR[fc]
;B[jb]CR[jb]
;W[kb]CR[kb]C[W +2]))
(;B[ha]CR[ha]
;W[db]CR[db]
;B[da]CR[da]
;W[eb]CR[eb]
;B[ea]CR[ea]
;W[gb]CR[gb]
(;B[fb]CR[fb]
;W[ga]CR[ga]
;B[gc]CR[gc]
;W[hb]CR[hb]
;B[hc]CR[hc]
;W[ib]CR[ib]
;B[fc]CR[fc]
;W[ic]CR[ic]
;B[hd]CR[hd]
;W[id]CR[id]C[W +3])
(;B[ga]CR[ga]
;W[hb]CR[hb]
(;B[ib]CR[ib]
;W[ic]CR[ic]
;B[jb]CR[jb]
;W[kb]CR[kb]
;B[fb]CR[fb]
;W[fc]CR[fc]
;B[ia]CR[ia]C[W +3])
(;B[ia]CR[ia]
;W[jb]CR[jb]
(;B[ib]CR[ib]
;W[ic]CR[ic]
;B[fb]CR[fb]
;W[fc]CR[fc]
;B[ja]CR[ja]
;W[kb]CR[kb]C[W +4])
(;B[ja]CR[ja]
;W[ib]CR[ib]
;B[kb]CR[kb]
;W[kc]CR[kc]
;B[ka]CR[ka]
;W[fb]CR[fb]
;B[ca]CR[ca]C[W +5]))
(;B[jb]CR[jb]
;W[ib]CR[ib]
;B[ia]CR[ia]
;W[kb]CR[kb]
;B[ja]CR[ja]
;W[fb]CR[fb]C[W +5])))
(;B[fb]CR[fb]
;W[db]CR[db]
;B[da]CR[da]
;W[eb]CR[eb]
;B[ea]CR[ea]
;W[hb]CR[hb]
;B[gc]CR[gc]
;W[hc]CR[hc]
;B[gd]CR[gd]
;W[gb]CR[gb]
;B[ec]CR[ec]
;W[ed]CR[ed]
;B[fc]CR[fc]
;W[hd]CR[hd]
;B[ga]CR[ga]
;W[ha]CR[ha]C[W +4])
(;B[hb]CR[hb]
;W[eb]CR[eb]
;B[ea]CR[ea]
;W[da]CR[da]
(;B[db]CR[db]
;W[ga]CR[ga]
;B[fb]CR[fb]
;W[gb]CR[gb]
;B[fc]CR[fc]
;W[gc]CR[gc]
;B[fd]CR[fd]
;W[gd]CR[gd]
;B[ec]CR[ec]
;W[ed]CR[ed]
;B[ca]CR[ca]C[W +5])
(;B[fb]CR[fb]
;W[db]CR[db]C[B is cut off and cannot form a live group.]))
(;B[ga]CR[ga]
;W[db]CR[db]
;B[da]CR[da]
;W[eb]CR[eb]
;B[ea]CR[ea]
;W[hb]CR[hb]
;B[ha]CR[ha]
;W[ib]CR[ib]
;B[ia]CR[ia]
;W[ja]CR[ja]
;B[gb]CR[gb]
;W[gc]CR[gc]
;B[fb]CR[fb]
;W[fc]CR[fc]
;B[ca]CR[ca]C[W +7])
(;B[ib]CR[ib]
;W[eb]CR[eb]
;B[ea]CR[ea]
;W[da]CR[da]
;B[db]CR[db]
;W[gb]CR[gb]
(;B[fb]CR[fb]
;W[fc]CR[fc]
;B[ec]CR[ec]
;W[ga]CR[ga]
;B[eb]CR[eb]
;W[fd]CR[fd]C[W +7])
(;B[ga]CR[ga]
;W[ha]CR[ha]
;B[ca]CR[ca]
;W[fb]CR[fb]
;B[da]CR[da]
;W[hb]CR[hb]C[W +12])))
(;B[ea]CR[ea]
;W[db]CR[db]
(;B[da]CR[da]
;W[fk]CR[fk]
;B[hb]CR[hb]
;W[fb]CR[fb]
;B[fa]CR[fa]
;W[gb]CR[gb]
;B[ga]CR[ga]
;W[hc]CR[hc]
;B[ib]CR[ib]
;W[ic]CR[ic]
;B[jb]CR[jb]
;W[kb]CR[kb]
(;B[ja]CR[ja]
;W[eb]CR[eb]
;B[ha]CR[ha]C[W +1])
(;B[eb]CR[eb]
;W[ec]CR[ec]
;B[ja]CR[ja]
;W[ha]CR[ha]
;B[ia]CR[ia]C[W +1]))
(;B[fk]CR[fk]
;W[da]CR[da]
;B[ca]CR[ca]C[W +1]))
(;B[db]CR[db]
;W[fk]CR[fk]
(;B[fb]CR[fb]
;W[gb]CR[gb]
(;B[hb]CR[hb]
;W[ga]CR[ga]
;B[gc]CR[gc]
;W[fc]CR[fc]
;B[ec]CR[ec]
;W[hc]CR[hc]
;B[fd]CR[fd]
;W[gd]CR[gd]
;B[fc]CR[fc]
;W[ib]CR[ib]
;B[fa]CR[fa]
;W[ha]CR[ha]C[W +1])
(;B[gc]CR[gc]
;W[hb]CR[hb]
(;B[ec]CR[ec]
;W[hc]CR[hc]
;B[gd]CR[gd]
;W[fd]CR[fd]
;B[fc]CR[fc]
;W[fa]CR[fa]
;B[ea]CR[ea]
;W[ga]CR[ga]
;B[hd]CR[hd]
;W[id]CR[id]C[W +2])
(;B[fc]CR[fc]
;W[hc]CR[hc]
;B[ec]CR[ec]
;W[fa]CR[fa]
;B[ea]CR[ea]
;W[ga]CR[ga]
;B[gd]CR[gd]
;W[hd]CR[hd]C[W +3]))
(;B[ga]CR[ga]
;W[ha]CR[ha]
;B[fa]CR[fa]
;W[hb]CR[hb]
;B[fc]CR[fc]
;W[gc]CR[gc]
;B[fd]CR[fd]
;W[gd]CR[gd]
;B[ec]CR[ec]C[W +2]))
(;B[ga]CR[ga]
;W[eb]CR[eb]
;B[ea]CR[ea]
;W[fb]CR[fb]
;B[fa]CR[fa]
;W[hb]CR[hb]
(;B[gb]CR[gb]
;W[gc]CR[gc]
;B[hc]CR[hc]
;W[ha]CR[ha]
;B[da]CR[da]
;W[ic]CR[ic]
;B[fc]CR[fc]
;W[gd]CR[gd]
;B[ec]CR[ec]C[W +1])
(;B[ha]CR[ha]
;W[ib]CR[ib]
;B[gb]CR[gb]
;W[gc]CR[gc]
;B[ia]CR[ia]
;W[ja]CR[ja]
;B[da]CR[da]C[W +7])))
(;B[da]CR[da]
;W[fk]CR[fk]
(;B[gb]CR[gb]
;W[eb]CR[eb]
;B[ea]CR[ea]
;W[fb]CR[fb]
;B[fa]CR[fa]
;W[hb]CR[hb]
;B[gc]CR[gc]
;W[hc]CR[hc]
;B[ha]CR[ha]
;W[ia]CR[ia]
;B[ga]CR[ga]
;W[ib]CR[ib]
(;B[db]CR[db]
;W[fc]CR[fc]
;B[fd]CR[fd]
;W[ec]CR[ec]
;B[gd]CR[gd]
;W[hd]CR[hd]C[W +1])
(;B[fc]CR[fc]
;W[gd]CR[gd]
;B[db]CR[db]
;W[ec]CR[ec]
;B[fd]CR[fd]C[W +2]))
(;B[fa]CR[fa]
;W[eb]CR[eb]
;B[ea]CR[ea]
;W[gb]CR[gb]
;B[ga]CR[ga]
;W[hb]CR[hb]C[The best from this is W +6.])))
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