(;CA[utf-8]RU[Japanese]TC[3]TT[30]GM[1]FF[4]C[Tan Xiao was rated the top Chinese player in 2011, and has been a point getter for China in the Nongshim Cup. I am choosing this game to display Master's peep to the 5-5 point, another move that was considered to be a bad exchange before Master played it. ]
AP[CGoban:3]SZ[19]ST[2]DT[2017-01-03]PC[The KGS Go Server at http\://www.gokgs.com/]
PB[Master]BR[9p]PW[Tan Xiao]WR[9p]KM[7.5]TM[60]RE[B+Resign]MULTIGOGM[1]
;B[pd];W[dp];B[qp];W[cd];B[ec];W[oq];B[fq];W[dn]C[Master played this opening twice, and in both cases played a peep at 5E. The variation for Black's next move shows part of the other game. There was a third game in which Master played the peep against Fan Tingyu in a completely different board position. ]
(;B[lp]C[This is the game sequence. When I was a young player, the natural move for White was to jump out first, but that is not played so much now (see var). ]
(;W[jq];B[eo]C[This peep is thought to usually be a bad exchange when White connects. It has been played in human pro games as a ko threat or a ladder breaking move, and locally it can sometimes work when Black intends to follow up by sliding on the second line (see var for Black 13). ]
;W[do]TR[fq]C[A var for Black's next move is added to show that Black has lost the option of jumping into the 3-3 point. That being an example of the negative aspect of Black 11, the exchange for 12 can help Black in the lower side fight. Another var is added to show how human players usually immediately follow with a slide to the second line.  ]
(;B[pq];W[op];B[pn]C[In this difficult position White seems to have a number of moves to choose from, and should be thinking of attacking when Black has a weak group on the left.  I don't like the game move (two variations added for White's move). ]
(;W[lq]C[White 16 has been played in pro games, so if one just looks at the position in the lower right, I suppose it's feasible. In this game position, I feel that White is not playing strongly enough when Black has a weak group on the left. ]
;B[mq];W[mp]C[Black must be willing to sacrifice the less valuable stone (see var for a bad example). ]
(;B[lo]C[White can avoid a fight (see var). ]
(;W[kp]C[White plays strongly here (see var). ]
(;B[mr]TR[lr]C[Black's strongest move (M2 could have been played first). ];W[mo]
C[Black can afford to sacrifice the two stones on the side, but not the two stones in the center. A variation for Black's next move shows an example of  what not to do for Black. ]
(;B[mn]C[This is an opportunity for White to capture the two Black stones, as in the var, but...]
(;W[on]C[White moves out. ];B[or];W[po]C[Answering on the right is bad for Black (see var). ]
(;B[nn]C[This powerful move destroys White's shape. The game is already looking bad for White now. ]
;W[oo];B[lr];W[kq];B[ko];W[jo];B[jn];W[io];B[in];W[ho];B[om]TR[no]C[Black forces with 31 to 35, and continues to attack with 37. The right side is so big that both players will not have time for the lower left for a while.]
;W[pm];B[pl];W[qm];B[ql];W[qo];B[rm];W[qn];B[hn];W[go];B[qr]TR[dr]C[White is not completely alive yet (see var). ]
(;W[rk];B[rl];W[no];B[nl];W[nq];B[qf]C[If White adds another move to the lower left, that territory will be close to 40 points, but Black's moyo is so big that White must still try to reduce it, and does not have time to make the LL territory. ]
;W[ok];B[ol];W[kd];B[fm]C[This is not an urgent move, and I get the feeling that Master is already in safe mode. ]
;W[nc];B[de];W[ce];B[df];W[cg];B[me]TR[fm];W[lc];B[oc];W[mj];B[nd];W[qg];B[pg]C[White needs to protect the upper side first (see var). ]
(;W[hc]C[White desperately tries to play on all sides at once. ];B[kj];W[qh];B[rf]
;W[oi];B[lh];W[mh];B[mg];W[lk];B[km];W[li];B[ki];W[ng];B[nh];W[qj];B[mi];W[ri];B[nk]
;W[ni];B[lj];W[rg]C[White managed to live, but it was painful. ];B[dr];W[cq];B[cr]
C[Black is alive on the lower side. I see no chances for White after this, so the commentary ends here. ]
;W[nr];B[ns];W[gr];B[bq];W[bp];B[dq];W[fr];B[ep];W[en];B[cp];W[bo];B[fo];W[fn];B[gq]
;W[hq];B[ir];W[er];B[eq];W[iq];B[gp];W[dg];B[ek];W[rp];B[rq];W[gm];B[gk];W[cc];B[gd]
;W[fg];B[gc];W[id];B[mc];W[hf];B[hb];W[ib];B[fb];W[ha];B[db];W[ck];B[dj];W[cj];B[cb]
;W[oh];B[di];W[ci];B[hh];W[mh];B[mk];W[hl];B[hk];W[pp];B[qq];W[bb];B[ba];W[ab];B[gb]
;W[lb];B[mb];W[jg];B[gl];W[ln];B[kn];W[li];B[hr];W[jr];B[es];W[is];B[mi];W[fe];B[fd]
;W[li];B[fs];W[hs];B[mi];W[of];B[pf];W[li];B[dl];W[cl];B[mi];W[sf];B[se];W[sg];B[rd]
;W[li];B[hd];W[ic];B[mi];W[em];B[fl];W[li];B[lg];W[fi];B[eh];W[gh];B[hi];W[eg];B[ro])
(;W[qh];B[rf];W[ph];B[hc]C[White's upper side group is weak. ]))
(;W[qf];B[nl];W[rn];B[sl];W[rp];B[rq];W[so];B[sq];W[sp]LB[sn:A]C[Black can choose a time to throw in at A for a ko. ]))
(;B[qo];W[pm];B[qn];W[ol]C[White has good shape. ]))
(;W[or];B[oo];W[np];B[lr];W[kq];B[ln]C[...Black has thick shape in the center, and a squeeze from the corner. This looks good for Black. ]))
(;B[lr];W[kq];B[or];W[ln];B[ko];W[jn]C[White captures with a geta (net). The ladder with White's final move also works for White. ]))
(;B[lr];W[kq];B[np];W[mr];B[mo];W[nr]C[This would be a failure for Black. Black's side stones are not yet connected to the LR corner, so they cannot be called thickness. ]))
(;W[lr]C[White is safe if he plays here, but the low position is a bit painful. ]
;B[np];W[mr]C[White can connect, but is not happy with a low position. ])
(;W[mo];B[kq];W[lr];B[kr];W[mr];B[jp]C[Black is happy to trade. ]))
(;B[lr];W[kq];B[np];W[mo];B[nq];W[no];B[or];W[on];B[pm];W[pr]C[White has a strong position on the outside, and Black has bad aji in the corner. ]))
(;W[jo]TR[on]C[Next White can attach at P6 (marked) to attack. I think White has an even game at least if he plays here. ]
(;B[dr];W[cq];B[hq];W[on]C[White attacks on the lower side. ]
(;B[om];W[nn];B[pl];W[ln]C[Good for White])
(;B[ln];W[pm];B[qn];W[nm]C[This fight looks playable for White. ]))
(;B[no];W[eq]LB[do:D][eo:C][go:B][lr:A]C[A and B are miai, and this looks to be a trade. The exchange of C for D has become bad for Black. ]))
(;W[eq];B[jo];W[lq]C[In this var White takes the big point at 1 first, waiting for Black 2 before attaching at 3. Compared to the game sequence, this is a more natural flow of play for White. ]))
(;B[cq];W[dq];B[dr];W[er];B[cr];W[eq];B[bo];W[bn];B[co];W[cn]TR[do][eo]C[When Black invades to the 3-3 point, the marked exchange becomes very bad for Black, so Black playing as in this variation is not usually a good idea.])
(;B[dr];W[cq];B[hq]TR[do][eo]C[In this variation the marked exchange is not necessarily bad for Black. ]))
(;W[on];B[qm];W[ip]C[White attacks Black on the lower side. ]))
(;B[eo];W[do];B[mp];W[oo];B[pn];W[ol];B[on];W[no];B[nm];W[qq];B[rq];W[qr];B[mo]
C[White got into trouble here (see var). ]
(;W[rp];B[ro];W[qo];B[pp];W[po];B[qn];W[mq];B[nn];W[nq]C[White threatens to cut on the second line (see var). ]
(;B[qj]C[Black removes the threat of a cut while playing a large point on the right side (see var). ]
(;W[jq];B[de];W[ce];B[df];W[cg];B[kp];W[kq];B[md]LB[rn:A]C[Master vs Sin Chinseo ( Shin Jinseo). In this game played later in the 60 game series Master peeped before playing the 1-space pincer. White 14 should have been played at 17. Black 23 was an efficient move that protected against the cut at A. The trade in the lower right was good for Black and Black had a good position with 31(final move). ])
(;W[rn];B[sp];W[rm];B[ql];W[rl];B[rk]C[Black wins the semeai. ]))
(;B[kp];W[rn];B[sp];W[rm]C[The semeai favors White. ]))
(;W[pp]C[Better for White.])))