(;AP[GOWrite:3.2.0]ST[2]FF[4]CA[UTF-8]GM[1]SZ[19]PB[Trouble master]PM[2]FG[259:]GN[Trouble Master Book 2 problem 1(done)]KM[6.50]RU[Japanese]PW[YD S28 4th lecture];PL[W]C[Book 2 problem 1
Level ***]AW[ok][ca][jf][sk][nf][pf][sf][ma][qa][gs][cn][ms][gn][hn][di][kn]
[ln][fi][gi][nn][rn][ed][gd][jd][qi][ri][si][nd][cq][dq][bl][iq]
[jq][dl][lq][fl][gl][nq][dg][rq][eg][ml][gg][ab][ol][bb][pl][cb]
[jg][db][rl][sl][mg][pg][lb][sg][ob][pb][qb][bo][eo][fo][ej][mo]
[ee][he][ie][ke][le][ne][oe][gr][hr][ir][kr][mr][gm][im][ch][dh]
[lm][mm][ac][hh][om][ih][qm][dc][ec][fc][mh][nh][oh][ph][qh][kc]
[lc][sh][mc][oc][bp][ep][ck][ek][np][op][pp][qp][rp][ff]AB[qk][da][kf][rk][ea][lf][fa][mf][qf][ka][la][ra][fs][fn][os][in]
[ci][jn][ad][hi][ii][ji][dd][mi][ni][hd][id][pi][ld][md][od][pd]
[bq][fq][gq][hq][kq][hl][oq][pq][qq][ll][nl][ql][kg][eb][gb][ib]
[qg][kb][rg][rb][go][ho][bj][cj][dj][ko][gj][be][de][kj][oj][pj]
[qj][rj][sj][me][pe][re][se][br][cr][dr][er][fr][fm][nr][hm][bh]
[km][rr][sr][gh][nm][bc][pm][cc][jh][lh][gc][jc][rh][pc][qc][cp]
[fp][bk][ip][kp][fk][hk][cf][jk][df][ef][lk][mk][nk]
(;LB[ia:A][rc:B][ge:C][bg:D][em:H][jm:F][pn:E][qs:G])
(;B[tt]
(;FG[259:]PM[2]MN[1];W[ia]C[A: Dia 1:
This is a vital point. It is important to
hold back the A-B sente exchange before
playing this attachment. Black has several responses, but none of them work]LB[ga:B][fb:A]
(;FG[259:]PM[2]GOWRITEFG[includePastCount:0];B[ha];W[fb];B[ga]
;W[hc]C[Dia 2: Black 2 is the standard response.
However, White 5 is double atari, and
the whole group dies!])
(;FG[259:]PM[2];B[jb];W[ga];B[ha]
;LB[hc:A]TR[da][ea][fa][eb]W[fb]C[Dia 3:
This response does not work either.
White 3 is a throw in tesuji and after
5, it creates a similar result to Dia. 2.
Black cannot save the four triangled stones because of the double atari at A]))
(;FG[259:]PM[2]MN[1];W[fb];B[ga];W[ia]
;C[Dia 4\: If White ataris first, nothing works. So
it is important to refrain from obvious
sente exchanges!]B[jb]LB[ga:2][ia:3][fb:1][jb:4])
(;FG[259:]PM[2]MN[1];W[rc]C[B: Dia 1: This technique is precisely the same
concept as problem A. It is crucial not to
make the A-B exchange before playing
this cut!]LB[qe:B][rf:A]
(;FG[259:]PM[2]MN[2];B[rd]
;LB[qe:A][sc:B]TR[qf][qg][rg][rh]W[rf]C[Dia 2: If Black responds with 2, it is easy.
White can atari at 3 and look for A or B
as miai.])
(;FG[259:]PM[2];B[sc];W[rd];B[sd]
;W[rf]TR[qf][qg][rg][rh]C[Dia 3: Therefore, Black must atari underneath
at 2. However, even after reaching 5,
Black has to sacrifice the four triangled stones.
If Black tries to save those four stones...];FG[259:]PM[2];B[qe];W[sb];B[qd]
;W[rc]C[Dia. 4
White can set up a double snap back
with 7 and 9.]TR[rc]))
(;FG[259:]PM[2]MN[1];W[rf];B[qe];W[rc];B[sc];W[rd]
;B[sb]LB[sb:6][rc:3][sc:4][rd:5][qe:2][rf:1]C[Dia 5:
If White plays the atari at 1 before 3,
Black can simply respond with 6, and
there will be nothing for White here.])
(;FG[259:]PM[2]MN[1];W[bg]C[D:];B[cg];W[ah];B[bi];W[cd];B[bd];W[bf];B[ce];W[af];B[ai]
;W[ak]C[Dia 1:
This is a forced sequence, and the
outcome is a one-step ko, which can be
quite challenging for Black to handle.])
(;FG[259:]PM[2]MN[1];W[jm]C[F:];B[kl]
;W[jo]C[Dia 1:
A bonus problem. You must be able to
identify this type of issue with 100% accuracy in your games!]LB[kl:2][jm:1][jo:3])
(;FG[259:]PM[2]MN[1];W[qs]C[G: Dia 1:
Another problem of the same type as
problems A and B. Keep a hold of the A-B
exchange until playing a move inside]LB[or:B][qs:1]
(;FG[259:]PM[2];B[qr];W[rs]
(;B[or]
;W[ps]C[Dia 2:
This is the best result for both. White
can create a seki, nullifying Black's territory entirely, as opposed to conceding
six points.]LB[or:4][qr:2][ps:5][rs:3])
(;B[ps]
;W[or]LB[or:5][qr:2][ps:4][rs:3]C[Dia 3:
Black 4 is the wrong response. The
throw-in at White 5 is a well-known
skill. Black is dead.]))
(;FG[259:]PM[2];B[rs];W[ns];B[qr];W[or]
;C[Dia 4:
Black can respond like this to make a
three-point living shape. But it costs one
point to live, so it is two points better
than seki. Nonetheless, this choice results in losing sente.]B[ps]LB[or:5][qr:4][ns:3][ps:6][rs:2])))
(;C[C:]B[kd];W[je];B[ge];W[fd];B[ig];W[hg]
;C[Dia 1: 
Finding this type of trouble is not
dependent on reading skills; it is more
about having the intuition to notice it,
and that sense comes from experience.]B[hf])
(;C[E:]B[pn];W[on];B[rm];W[sm]
;B[qn]LB[rm:3][sm:4][on:2][pn:1][qn:5]C[Dia 1: 
Black 3 is a common throw-in technique. It rescues Black's three stones
through a ko.])
(;C[H:]B[dp];W[eq]
;B[em]LB[el:B][em:3][do:A][dp:1][eq:2]C[Dia 1: 
A move like 3 can often be overlooked
by many Go players because it creates
an "ugly" empty triangle shape and
doesn't employ any fancy techniques.
However, in this situation, it is the only
possible option since A and B are miai.]))
