(;
AB[rc][qc][pd][nd][nb][pj][pk][rk][ri][nj][mj][lj][jj][pm][qm][rm][le][nn][oo][op][np][mp][mo][pp][pr][qq][rq][lp][kp][mq][hq][md][ke][jd][ic]
AW[dd][dp][fq][lb][ld][qd][qe][pf][ph][of][ne][me][lf][mg][ng][kg][mi][rl][ql][pl][ol][om][mm][mn][on][po][pn][qn][ro][rp][qp][or][nq][mr][lq][lo][iq]
TR[iq]
C[Black's response to the marked severe play?

Black has strong formations and a territorial lead.  If Black can retain control after this challenge at the bottom, Black will have good prospects for winning the game.

Source:
    1995 Cotsen Open demo game:  Yilun Yang 7P vs. Ru Nan Wang 8P
    American Go Journal, p. 25, Vol. 29, No. 3, 1995]
(;
B[ip]
C[This hane from the top is what White is hoping for.];
W[hr];B[jq];W[ir];B[jr]
C[Black must descend here to protect the big bottom right area, but ...];
W[dj]
C[... White has sente to take the huge left side star point.]
)
    (;
    B[ir]
    C[This hane from below is correct.]
    (;
    W[jq]
    C[White's extension here looks dangerous, but ...];
    B[jr];W[kq];B[hp]
    C[... White cannot save the bottom group.]
    )
        (;
        W[jr]
        C[The game move.  White wants to make good shape with the bottom stones, while keeping sente.];
        B[jq];W[ip];B[kr]
        C[Simple, profitable, and sente.];
        W[hr];B[js];W[hp]
        C[White must come back here to protect these stones.];
        B[cj]
        C[Black has sente to split the left side to keep the game simple.  Now White's chances to make a big territory on the left or center to catch up are slim.  Black went on to win the game.]
        )
    )
)

