(;FF[4]
CA[UTF-8]
GM[1]
GN[Becoming 9 Kyu - Lesson 24]
PC[https://online-go.com/review/413077]
PB[Black]
PW[White]
BR[2d]
WR[2d]
OT[Error: time control missing]
RE[?]
SZ[19]
KM[6.5]
RU[Japanese]

(;B[qd]
;W[pj]
;B[oc]
;W[qe]
;B[pe]
;W[qf]
;B[pf]
;W[rd]
;B[qg]
;W[rg]
;B[qh]
;W[rh]
;B[qi]
;W[rj]
;B[ri]
;W[si]
;B[qc]
;W[qj]
;B[oh]C[Hi! Let's investigate tactics on the first line. I imagine you've found yourself in trouble because of shortage of liberties before. I hope you can identify first-line tactics so you don't get trapped in a liberty shortage after this lesson!]
;W[rc]C[Pushing here is an endgame play.]
(;B[rb]
;W[sb]
;B[qb]
;W[dp]C[White, however, tenukies here. What will the consequences be? White's moves here will result in a liberty shortage. Black has a good tesuji to punish White.]
;B[re]C[Cutting here is a good start.]
;W[rf]C[After White connects,]
;B[se]C[This descent is part of a great combination.]
;W[sf]LB[sd:A]C[Since White can't atari at A, White needs to play here to capture the two black stones. What can Black do now?]
;B[sh]C[This throw in is a nice tesuji! Because of the snapback, White can't capture this stone.]
;W[sd]C[Instead, White can only capture the two stones.]
;B[sj]C[But what if Black captures this white stone? The entire group dies. T17 is a false eye. The entire group dies. It's a false eye. Of course this result is disastrous for White.]
)(;AE[rc]C[Going back to the original variation, White has no weaknesses at the moment.]
;AW[rc]C[This endgame move was the main cause of White's liberty shortage.]
;B[rb]C[As we saw, the consequences were dire. Let's look at another first line tesuji.]
))(;B[pd]
;W[nd]
;B[lc]
;W[mb]
;B[lb]
;W[pc]
;B[oc]
;W[od]
;B[qc]
;W[pb]
;B[qd]
;W[pe]
;B[oe]
;W[qe]
;B[of]
;W[re]
;B[qb]
;W[qg]
;B[nb]
;W[mc]
;B[ma]
;W[rd]
;B[nc]
;W[md]
;B[le]C[Black plays here to capture White's group in a net. Is this group supposed to die?]
;W[rb]C[This attachment is just an endgame move.]
(;B[pa]C[Some players would choose to play this way. By exploiting White's weaknesses, however, Black can rescue the whole group.]
)(;AE[rb]C[What's the move?]
(;AW[ld]C[This push only reduces liberties. It's not the answer.]
;B[kd]
)(;AW[qa]C[This move is conceivable.]
;B[ra]C[Black would answer here on the first line. White can't connect due to shortage of liberties, so White has to make a ko.]
;W[oa]
;B[pa]C[This also isn't the best answer.]
)(;AW[na]C[This move looks tesuji-ish, but it goes nowhere.]
;B[oa]
)(;AW[pa]C[Descending is another move you can consider.]
;B[oa]C[Black can resist here, however.WBlack can resist here, however.]
)(;AW[oa]C[First of all, White needs to diagonal on the first line, like this. Now White can't avoid a liberty shortage.]
;B[na]C[Black has no choice but to connect here.]
(;W[rb]C[After that, White attaches here. The previous exchange is working well! Black can't play P18 because of a liberty shortage.]
(;B[la]C[Therefore, Black needs to connect here first.]
;W[rc]C[Then White can capture four black stones. White saved the five stones beautifully.]
)(;B[qa]
;W[rc]
;B[ra]
(;W[dp]
;B[me]
;W[sa]
;B[sb]
;W[sc]
;B[ne]
;W[sa]
;B[ld]C[?]
)(;W[sa]
;B[sb]
;W[sc]
;B[me]
;W[sa]
)(;W[sb]
)))(;W[qa]
;B[ra]
;W[rb]
))(;AW[ob]C[This atari is a bad move.]
;B[na]C[After Black connects, White has no follow up.]
))))