(;
AB[hs][br][gr][nr][bq][cq][fq][mq][oq][dp][ep][fp][gp][hp][ip][mp][co][jo][ko][lo][mo]
AW[es][fs][cr][dr][fr][lr][mr][dq][eq][gq][hq][iq][jp][kp][lp][bo][eo][fo][io][cn][cm][fm][hn]
C[Black plays.

Source:  Korean life and death booklet.];
B[cs]
C[Black can probably also start in the middle of the lower side, but this move is clearest.]
(;
W[gs]
LB[hr:A]
C[(Or A.)  Seems normal, but this move makes Black's job easier.];
B[bs]
C[Looks slow, but ...];
W[hr];B[ds]
C[... even though White can capture one of the cutting stones, White has a liberty shortage preventing White from connecting.  So Black captures 4 stones to live.]
)
    (;
    W[ds]
    C[Toughest defense.];
    B[bs]
    C[Black still plays this "slow" move.]
    (;
    W[is]
    C[Toughest defense.]
    (;
    B[jq]
    C[Correct.]
    (;
    W[jr];B[ir];W[kq];B[js]
    LB[gs:A]
    C[Black ataris at A next.]
    )
        (;
        W[kq]
        C[Worse.];
        B[jr]
        C[White loses everything.];
        W[ir];B[js]
        )
    )
        (;
        B[ir]
        C[Fails.];
        W[jq]
        C[At best, Black has a ko.]
        )
    )
        (;
        W[hr]
        C[White can save the bottom left stones, but ...];
        B[jq];W[gs];B[lq]
        C[... Black captures 3 stones to save the lower left group.]
        )
    )
)

