(;FF[4]
CA[UTF-8]
GM[1]
GN[Becoming 9 kyu - Lesson 17]
PC[https://online-go.com/review/404537]
PB[Black]
PW[White]
BR[2d]
WR[2d]
OT[Error: time control missing]
RE[?]
SZ[19]
KM[6.5]
RU[Japanese]

(;B[pp]
;W[qq]
;B[qp]
;W[pq]
;B[oq]
;W[or]
;B[pr]
;W[qr]
;B[nr]
;W[ps]
;B[nq]
(;AB[rp]
;W[rq]
;B[sp]
;AB[rs]
(;W[os]C[Hi! Let's see how to capture stones using shortage of liberties. Look at this puzzle. Black has to capture the white group. How should Black play?]
(;B[sq]C[How about pushing here?]
;W[sr]C[White will block here.]
;B[rr]C[If Black cuts,]
;W[qs]C[White will atari here. White's already alive.]
;B[ss]C[Capturing this stone is of no use.]
;W[sr]C[White can recapture the three black stones in a snapback. It's no good. Pushing was careless.]
)(;B[ns]C[Let's try this one.]
;W[rr]C[White can easily make two eyes by playing at 2-2. Now Black can't save the stone. So this move isn't the answer either.]
)(;B[sr]C[This diagonal at 1-2 is the move.]
;W[sq]C[White has no choice but to cut Black like this. How should Black play now?]
;B[qs]C[Black wedges here. As soon as Black plays here, the white group dies. If you consider shortage of liberties when attacking your opponent's groups, you'll often get a good result. To help you remember this technique, I prepared two more situations for practice.]
;W[rr]C[Now White can't atari here because it would be self atari.]
;B[pr]C[Black will capture the six white stones.]
))(;W[rr]
(;B[ns]
;W[os]
)(;B[os]
;W[ns]
;B[ms]
;W[os]
))(;W[sr]
;B[ns]
;W[os]
))(;AE[rp]
;W[rq]
;B[sp]
;AE[rs]
;W[os]
))(;B[dq]
;W[do]
;B[eo]
;W[cq]
;B[ep]
;W[dr]
;B[dn]
;W[cn]
;B[dm]
;W[co]
;B[fn]
;W[cl]
;B[cm]
;W[bm]
;B[cr]
;W[bl]
;AW[gq]
;AW[er]
;B[br]
;W[bq]
;B[eq]
;W[fr]
;B[ar]
;W[aq]C[Here is the second puzzle. Black to exploit a shortage of liberties. How should Black play?]
(;B[bn]C[First, cutting right away doesn't work.]
;W[cp]C[White will connect and have 4 liberties compared to Black's 3 liberties in the corner. Black did not exploit a lack of liberties in this way.]
)(;B[bo]C[Striking this point also does not exploit a shortage of liberties.]
;W[cp]C[Because White can connect here and have 4 liberties, same as before.]
)(;B[bp]C[This move is no different.]
;W[cp]C[White connects and gains more liberties than Black's 3 liberties in the corner.]
)(;B[cp]C[Because White plays here in response to all other move options for Black, you should think about playing it yourself. Indeed, this is the answer.]
(;W[bp]C[If White plays atari here,]
;B[bo]C[Black cross cuts, and]
;W[dp]
;B[bn]C[The shortage of liberties results in a connect-and-die situation.]
)(;W[bo]C[This move is not helping.]
;B[bp]C[Black captures directly.]
)(;W[ao]C[This move was mentioned, and it's a stronger resistance. But it, too, doesn't work if Black finds the response.]
;B[bo]C[Black will play here to exploit the shortage of liberties. I hope you remember to look for shortage of liberties in your own games. This technique can be very useful in dire circumstances. Let's look at one more example from a professional game that doesn't involve life and death.]
)))(;B[pd]C[This game was between Yu Changhoek and Lee Changho.]
;W[dd]
;B[qp]
;W[dp]
;B[nq]
;W[qj]
;B[ql]
;W[qf]
;B[mc]
;W[fq]
;B[qh]
;W[rh]
;B[qi]
;W[ri]
;B[pj]
;W[qk]
;B[pk]
;W[rl]
;B[rm]
;W[pi]
;B[ph]
;W[pl]
;B[qm]
;W[oi]
;B[ok]
;W[pe]
;B[oh]
;W[qd]
;B[pc]
;W[qc]C[This is our starting position. Black is cut in three pieces on the right side. Black would like to exploit a shortage of liberties to connect them all together. How should Black play?]
(;B[rg]
;W[qg]C[Let's make this exchange first to highlight the shortage of liberties.]
(;B[sk]C[This move was suggested, but White has an answer for this.]
;W[rj]C[White will connect here. Black can capture one stone, but the three groups remain separated, so it's a failure.]
)(;B[rj]C[This is the tactic to start the shortage of liberties.]
;W[rk]C[White would connect, and]
;B[sj]C[Black descends. Now the shortage of liberties is clear. Black will capture at least four stones and connect the three groups together. You can see that shortage of liberties can be a useful tactic in life and death situations and even if there's not a life and death situation.]
))(;B[rj]
(;W[rg]
)(;W[rk]
;B[sj]
(;W[si]
;B[rg]
;W[sk]
;B[qg]C[This would be disastrous for White, so White wouldn't connect and capture like this.]
)(;W[rg]
;B[sl]
)))))