(;GM[1]FF[4]CA[UTF-8]AP[CGoban:3]ST[2]
RU[Japanese]SZ[19]KM[0.00]
PW[Baduk]PB[Movies]
(;B[]
;W[dc]
;B[de]
;W[ce]
;B[cf]
;W[cd]
(;B[df]
(;W[fc]LB[dd:B][ed:A]C[In this shape, black can often play testing moves at either A or B. But when does black play which move, and why? ]
(;B[dd]
(;W[cc]C[This connection is the most usual move. ]
;B[hc]C[However it gives black aji with this move.]
;W[pp]
;B[eb]C[The local tesuji.]
;W[fb]
;B[ec]
;W[ed]
;B[fd]
;W[ee]
;B[fe]C[Depends on a ladder.])
(;W[ed]C[Puts focus on the top side, but gives away some points on the left. 
]
;B[cc]
;W[bc]
;B[cb]
;W[bb]
;B[bf]C[In some cases black is very happy to get this extension on the second line. 

White can think about 3 ways of answering this move.]
(;W[ad]C[The correct move.]
;B[ae]
;W[bd]
;B[db]
;W[ec]C[Eye vs. no eye. Black is captured.])
(;W[ae]C[This move is sometimes good when black has a big territory on the left side]
;B[be]
;W[bd]
;B[db]
;W[ec]
;B[ad]LB[cc:A]C[However, it is painful for the corner here. white will need to spend more stones to capture A.])
(;W[be]C[This move is not good for the points in the corner, but could be played to take away liberties of the black group. This would only be played in a semeai.]))
(;W[bc]C[Sometimes this can be a good move too.]
;B[hc]LB[eb:A]C[However, when black plays here, there is big aji at A.]
;W[]
;B[eb]
;W[fb]
;B[ec]
;W[ed]
;B[db]
;W[cc]
;B[fd]
;W[ee]
;B[gc]LB[fe:A]C[Black can capture two stones like this, or can also play A when the ladder is good for black.]))
(;B[ed]C[Sometimes black can play this too.]
(;W[ec]C[This answer is normal.])
(;W[gb]C[This is also possible but there is a disadvantage.]
;B[bf]C[Later when black's stone is here..]
;W[pd]
;B[ec]
;W[eb]
;B[bc]
(;W[bd]
;B[cc]
;W[dd]
;B[ad]C[There is better endgame for black.])
(;W[cc]
;B[bd]
;W[be]
;B[ae]
;W[bb]
;B[ab]C[or like this.]))
(;W[gc]C[This is also possible, but..]
;B[ec]
;W[eb]
;B[fb]
;W[db]
;B[hc]C[Black can use this kind of move later.])
(;W[fd]C[Another possibility. This however gives black the chance to make his left side stronger.]
;B[ec]
;W[eb]
;B[db]
;W[fb]
;B[cb]
;W[bc]
;B[bb]
(;W[ab]C[Correct move.]
(;B[be]
;W[cc]
;B[bd]
;W[bf]C[Sacrificing tesuji.]
;B[bg]
;W[da]C[White can capture  the corner. And got some influence at the top. However, black became very strong on the left.])
(;B[cc]C[Ofcourse black can give this atari and then double atari, but it's good for white.]
;W[dd]
;B[bd]
;W[be]
;B[ac]
;W[ee]C[good for white!]))
(;W[dd]C[Bad move. Taking your own liberties!]))))
(;W[ed]C[This is an example from a professional game.]
;B[dj]
;AW[mb][hc][nc][nd][le][me][qh][qk][cn][qn][dp][cq]AB[nb][ob][oc][jd][ld][pd][pf][qp][fq][iq][pq][dr]
;AW[fb][gb][lc][mc][qd][je][ke][qe][kf][qf][lg][ng][rg][mh][qi]AB[kb][lb][gc][kc][gd][he][ie][pe][jf][kg][pg][qg][jh][lh][ph][ki]C[This is a position from a professional game between Hua Yigang 8p and Ishida Akira 9p from 1985
For video, see: http://www.56.com/u73/v_NTQxMzYyNTQ.html]
;B[dd]C[Black plays here. How to react?]
(;W[bc]C[Right answer.]
;B[bf]LB[ac:A]C[This is no longer sente in endgame. Black can not play the monkeyjump at A anymore.])
(;W[ec]C[Not good.]
;B[bf]C[Black lost in the exchange. ])
(;W[cc]C[Not good either.]
;B[bf]C[This becomes sente in endgame.]
;W[]
;B[ac]C[Otherwise black could play here afterwards.])
(;AE[ed]AW[eb][bc]AB[ec][fd][be][ee][bg]LB[be:A][bg:B]C[In endgame, black had stones around A and B. How to play in the upper left? There is big aji..]
;W[]
;B[ac]C[Tesuji.]
(;W[ab]C[Dangerous.]
;B[cb]
;W[cc]
;B[bb]
(;W[ad]
;B[db]C[White is dead.])
(;W[db]
;B[ad]C[A success for black.]
;W[ba]C[Although still a ko.]))
(;W[bd]C[Not good.]
;B[bb])
(;W[bb]C[Not optimal either.]
;B[bd]C[because black can play this atari in sente.]
;W[cc]
;B[ab]LB[ba:A]C[Because of the lack of liberties, on top of this black gets to play a huge hane at A aswell])
(;W[cc]C[Best answer for white.]
;B[ab]LB[bd:A]C[Black does not get the atari at A in sente.]))))
(;B[dg]C[Are things different with this?]
;W[fc]
;B[ck]
;W[dp]
;B[pd]
;W[pp]
;B[qj]
;W[cm]
;B[nc]
;W[ch]
;B[bg]
;W[bj]
;B[di]
;W[dh]
;B[eh]
;W[ci]
;B[dj]
;W[bk]
;B[ed]C[Now this is a good move?]))
(;AW[qj][pn][qn][po]AB[oc][qd][qh][qo][qp][nq][pq]
;B[ql]C[When black invades the right side, white has a nice testing move.]
(;W[pp]C[In this situation we use this move. Good timing!]
(;B[qq]C[The correct response here.]
(;W[pl]C[Note that this move is important.]
(;B[qk]
;W[pk]
;B[rj]C[Black can connect, but white is fine.]
;W[pj]
;B[ri]
;W[mo]LB[pp:A][qq:B]C[The exchange A and B is good.])
(;B[rl]C[Also possible here.]
;W[pk]
;B[rn]C[In this case white is fine too though. He has no cuttingpoints.]))
(;W[pk]C[Many people play here, it's a mistake.]
;B[pl]
;W[ol]
;B[rl]LB[ok:1][om:2]C[A miai move. It also leaves 2 cutingpoints.]))
(;B[op]C[An overplay here.]
;W[qq]
;B[rq]
;W[qr]
;B[rr]
;W[rn]C[This is sente.]
;B[sp]
(;W[qk]C[The tesuji! Black can not connect anymore. Black's invasion failed and white is safe.
]
(;B[pl]
;W[rl]C[Easy connection.])
(;B[rl]
;W[pl]C[White captures.]))
(;W[pl]C[This is a mistake.]
;B[qk]C[Black can still connect.])))
(;W[pl]
;B[qk]
;W[pk]
;B[rj]
;W[pj]
;B[ri]
;W[pp]C[If white asks now, at this moment, things change.]
;B[op]C[black will answer like this.]
;W[qq]
;B[rq]
;W[qr]
;B[rr]C[Cutting does not work.]
;W[rn]C[This move is not dangerous for black.]
;B[sp]))
(;AW[qf][pj][pn][qn][po]AB[nc][pd][qo][qp][nq][pq]
;W[]
;B[rl]C[When black invades here, white can play the same testing move.]
(;W[pp]C[We use this move in this case too.]
(;B[qq]C[The best move again.]
;W[ql]
;B[qk]
;W[pk]
;B[qm]
;W[pl]
;B[rn]
;W[pm]
;B[rm]LB[pp:A][qq:B]C[The exchange A and B was good timing.]
;AE[pp][qq]
;W[pp]C[If white would now play here...]
(;B[qq]C[Black would never react like this.])
(;B[op]C[Black would play here instead!]))
(;B[op]C[Wrong answer]
;W[rn]
;B[rp]
;W[qk]C[Black's invasion failed again. Good for white.])
(;B[rn]C[Looks tempting, but it is an overplay.]
;W[qq]C[This is a good testing move.]
(;B[oq]
;W[rm]
;B[ro]
;W[qm]
;B[rq]C[Good for white.])
(;B[rp]
;W[oq]
;B[pr]
;W[or]
;B[qr]
;W[np]C[White is very happy with this.])
(;B[rq]
;W[rm]
;B[ro]
;W[oq]
;B[qr]
;W[or]C[Good for white.])))
(;W[rm]C[If white plays here immediately, black can make life or escape.]
;B[pl]
;W[ol]
;B[qi]))
(;AW[dd][oe][pe][qe][mf][lg][kh][dj][pj][rj][kk][pk][pn][qn][po][dp]AB[fc][oc][kd][md][pd][qd][nh][ph][pi][ri][oj][ok][nn][qo][qp][nq][pq]
;W[no]
;B[mn]
(;W[pp]C[Now is good timing.]
(;B[qq]
;W[mq]C[Next good move]
(;B[lo]
;W[np]
;B[nr]
;W[lp]
;B[jo]
;W[jq]C[White escaped very easily.])
(;B[np]C[What white wants.]
;W[mo]
;B[mp]
;W[lo]LB[oj:A]C[This is white's intention. Black's group is weak now.]))
(;B[oq]C[If black answers here..]
;W[qq]
;B[rq]
;W[qr]
;B[rr]
;W[rn]
;B[sp]
;W[ol]
;B[nl]
;W[om]C[White can live easily.]))
(;W[mo]C[Too simple, black will get a good result.]
;B[lo]
(;W[mq]
;B[mp]
;W[np]
;B[op]C[This is a good move.]
;W[oo]
;B[lp]
;W[pp]
;B[oq]
;W[qq]
;B[rq]
;W[qr]
;B[rr]C[The cutting doesn't work now and gave too many points.])
(;W[mp]C[Bad shape.]
;B[kn])))
(;AW[qi][pm][qn][po]AB[oc][qd][qg][qo][qp][nq][pq]
(;W[]
;B[ql]
;W[rm]
(;B[rj]
;W[pk]
;B[pj]
;W[qj]
;B[qk]
;W[ok]
;B[ri]
;W[op]C[Good testing move that also defends white's cuttingpoint.]
;B[oq]
;W[qh]
;B[rh]
;W[oi]C[This is a old joseki.
]
;B[pl]C[Cutting here does not work.]
;W[ol]
;B[om]
;W[nm]
;B[on]
;W[nn])
(;B[pj]
;W[qj]
;B[qk]
;W[rk]
;B[rl]
;W[sl]
;B[rj]
;W[sk]
;B[pi]
;W[ri]
;B[qh]
;W[rh]
;B[rg]
(;W[ol]C[This is another old joseki.

The last move, kosumi, is necessary.]
(;B[ok]C[If black responds, white can tenuki.]
;W[dd]
;B[so]
;W[qm]C[This is white's sente, so there is no ko.])
(;B[dd]C[That's why black usually plays tenuki now.]))
(;W[dd]C[Tenuki is a mistake.]
;B[ol]C[this is the vital point.]
;W[nn]
;B[so]C[This is a almost sente.]
;W[ln]
;B[rn]
;W[qm]
;B[sm]C[There is ko.])))
(;W[pp]C[Why does white never play here?]
;B[qq]
;W[lq]C[Because even with this move, there is little aji in black's position.]
;B[dd]
;W[or]
;B[nr]C[Black can just block, and there is no ladder.]
;W[oq]
;B[op]
;W[np]
;B[oo]C[Oops, atari.])))
