(;GM[1]FF[4]CA[UTF-8]AP[CGoban:3]ST[2]
RU[Japanese]SZ[19]KM[0.00]
PW[백 Cho Hye Yeon 9p]PB[흑 my friends 2dan]C[Today's topic is the double-hane tesuji.
]
(;AW[dn][en][co][go][ho][cp][hp][jp][dq][fq][gq][dr]AB[dp][ep][fp][gp][bq][cq][hq][cr]C[Black to play.
]
(;B[eq]
;W[er]
;B[hr]
;W[fr]
;B[gr]
;W[fo]C[Black is dead!
])
(;B[hr]
;W[eq]
;B[gr]
;W[fo]C[Black loose...
])
(;B[gr]C[This is the first hane.
And...
]
(;W[fr]
(;B[hr]C[If black connects here...
]
;W[eq]
;B[es]
;W[fo]C[White wins a race to capture!
])
(;B[fs]C[This is the double-hane!
]
(;W[er]
;B[hr]
;W[fo]
;B[ds]C[Black wins a race by one move!
])
(;W[hr]
;B[er]
;W[gs]
;B[eq]C[Black is alive!
]))
(;B[ds]C[It is also working.
]))
(;W[eq]
;B[fr]C[White is completely ruined!

])))
(;AW[qm][mo][no][po][lp][qp][jq][lq][qq]AB[mq][nq][oq][pq]C[Black to play. ]
;B[qr]
;W[rr]
(;B[ps]
;W[mr]C[Black is suffering from death.
])
(;B[rs]C[This is the double-hane.
]
;W[sq]
;B[lr]
;W[kr]
;B[ms]C[White has no choice but to start a ko-fight.
]
;W[pr]
;B[ps]
;W[qs]C[No other choice! 
]))
(;AW[cm][dm][em][an][bn][cn][fn][co][dq][cr][dr][cs]AB[ho][gp][ip][bq][cq][fq][hq][br][gr][ir][bs]
;B[dp]
(;W[cp]
;B[ep]
;W[bp]
;B[er]C[Black wins a race!
])
(;W[ep]
(;B[cp]C[This connection is a terrible mistake.
]
;W[eq]
;B[eo]
;W[fo]
;B[bo]
;W[ap]C[Black is dead!
])
(;B[eo]C[This is the double-hane.
]
(;W[do]
;B[cp]
;W[eq]
;B[fo]
;W[bp]
;B[er]C[White is dead!
])
(;W[cp]
;B[do]
;W[fo]
(;B[eq])
(;B[fp]C[White is dead!
]))
(;W[eq]
;B[fo]C[White cannot be alive!
]))))
(;B[pq]
;W[qn]
;B[ql]
;W[qq]
;B[qp]
;W[pp]
;B[rq]
;W[qr]
;B[po]
;W[op]
;B[qo]
;W[rr]
;B[no]C[This is one of the famous jeongseoks.
]
;W[oo]
;B[on]
(;W[oq]
;B[pn]C[This is the right sequence.
])
(;W[np]C[If white pushes here...
]
;B[mp]C[Double-hane position!
]
;W[mo]
;B[nq]
;W[nn]
;B[oq]
;W[no]
;B[lp]
;W[pn]
;B[rn]
(;W[om]
;B[rp]C[White in the corner is dead. Black is very happy!
])
(;W[ro]C[If white cuts here...
]
;B[rp]
;W[rm]
;B[so]
;W[qm]
;B[om]
;W[rl]
;B[qk]
;W[sq]
;B[sr]
;W[ss]
;B[pr]C[White's situation becomes worse.
])))
(;B[pp]
(;W[pd]
;B[qn]
;W[qf]
;B[kq]
;W[pq]C[This is the attachment, and the following sequence is...
]
;B[oq]
;W[qp]
;B[qq]
;W[pr]
(;B[qr]C[If black blocks here...
]
(;W[op]
;B[po]
;W[or]
;B[nq]
;W[nr]
;B[mq]
;W[rp]
(;B[rq]
;W[sr]
;B[sq]
;W[qs]
;B[ps]
;W[rs]C[Black is dead!
])
(;B[rr]C[This move is interesting.
]
(;W[rq]
;B[sr]
;W[qs]
;B[ro]
;W[rs]
;B[sp]C[White is destroyed.
])
(;W[sr]
;B[sq]
;W[rq]
;B[ss]
;W[sp]C[A Ko-fight
])
(;W[qs]
;B[rs]
;W[sr]
;B[mr]C[White is in danger.
Thus...
])))
(;W[or]C[This move can be worthwhile to read.
]
(;B[nq]
;W[po]
;B[op]
;W[qo]
;B[rq]
;W[oo]C[One of the variations of jeongseok
])
(;B[op]
;W[nq]
;B[rp]
;W[np]C[One of the variations - white is not bad.
])))
(;B[or]C[Today's topic is this one.
]
(;W[qr]
;B[rq]
;W[op]
;B[po]C[white is in crisis. What can white do?
]
(;W[os]
;B[nq]
;W[rp]
;B[rr]
;W[rs]
;B[qs]C[White is dead.
])
(;W[nq]
;B[nr]
;W[mr]C[This is the double-hane tesuji!
]
;B[np]
;W[os]
;B[mq]
;W[ns]
;B[oo]
;W[rp]
;B[rr]
;W[rs]C[White is alive!
]))
(;W[rq]C[This move is also possible.
]
;B[qr]
;W[po]
;B[ps]
;W[qo]
;B[pn]
;W[oo]
;B[on]
;W[no]C[White can also play in this way.
])))
(;W[nq]
;B[np]
;W[op]
;B[oo]
;W[oq]
(;B[no]C[This is not good for black.
]
;W[pq]C[White is satisfied with it.
])
(;B[po]
;W[pq]C[This is one of the jeongseoks.
]
;B[qq]
;W[qr]
(;B[rr]C[Double hane-very important tesuji!
]
(;W[rq]
;B[qp]
;W[rs]
;B[mq]
;W[or]
;B[mp]C[Jeongseok!
])
(;W[mp]
;B[no]
;W[rq]
;B[qp]
;W[pr]C[Sometimes white plays in this way.
]))
(;B[mp]C[If black plays here...
]
;W[mq]
;B[lp]
;W[rq]
;B[qp]
;W[kr]C[White is not bad at all!
])))))
