(;
AB[or][mr][oq][op][oo][po][qo][ro][so]
AW[pr][rr][qp][rp]
C[Black plays.]
(;
B[sq]
C[An interesting try to ruin the eye-space, but ...];
W[sp];B[qq];W[rq]
C[... White can divide the space into two eyes.];
B[qs];W[ps]
)
    (;
    B[sp]
    C[Bad timing.];
    W[sq];B[ps]
    C[Too late.];
    W[qr]
    LB[rq:A][sr:B]
    C[White can dodge to here.  White has eyes at A and B.]
    )
    (;
    B[pq]
    C[Too slow.];
    W[qq]
    (;
    B[ps];W[qs]
    C[Black only has a ko.]
    )
        (;
        B[sq]
        C[No better.];
        W[sp];B[ps];W[qs]
        C[Black still has to settle for a ko.]
        )
    )
    (;
    B[ps]
    C[The only move.]
    (;
    W[qs]
    (;
    B[sq]
    C[Fails];
    W[sp]
    (;
    B[qq];W[rq]
    C[White already has 2 eyes.]
    )
        (;
        B[pq]
        C[Fails.];
        W[qr]
        C[White doesn't even have to settle for a ko.];
        B[sr]
        C[For example ...];
        W[ss];B[rs];W[rq]
        )
    )
        (;
        B[qq]
        C[Too soon.];
        W[pq]
        C[White has too many ways to make the 2nd eye.];
        B[sq]
        C[For example ...];
        W[rq]
        )
        (;
        B[pq]
        C[Better, but still fails.];
        W[qq]
        C[Black only has a ko.]
        )
        (;
        B[sp]
        C[Again, the only move.];
        W[sq]
        (;
        B[qq];W[pq];B[pp]
        )
            (;
            B[pq]
            C[Fails.];
            W[qq]
            C[Black only has a ko.]
            )
        )
    )
        (;
        W[qr];B[pq]
        C[Black collapses White's eye-space into a dead shape.];
        W[qq];B[qs];W[rs];B[sq]
        )
    )
)

