this position arises after a standard star-point joseki where black kakari's, white pincers, and black jumps. it looks like white has received unfair compensation, but there exists a sequence key to this position.
(;GM[1]FF[3]
RU[Japanese]SZ[19]HA[0]KM[5.5]
PW[White]
PB[Black]
GN[White (W) vs. Black (B)]
DT[1999-07-28]
SY[Cgoban 1.9.2]TM[30:00(5x1:00)];AW[dk][dn][dp][eq][hq][fr][gr]
AB[fo][ip][fq][gq][iq][hr]C[black's best move?
]
(;B[co]
(;W[do]
(;B[dr];W[er]
(;B[cp]
C[RIGHT
black lives on the inside. there's life & death here, but that's another problem...
])
(;B[cq]C[bad shape
])
)
(;B[er];W[dr])
)
(;W[cp];B[er]
C[white can save stones and be cut or give up and stay connected
])
)
(;B[dr];W[er];B[co];W[cp])
(;B[er];W[dr]
(;B[co];W[do])
(;B[ep];W[es])
)
(;B[ep];W[dr])
(;B[hp];W[dr])
(;B[en];W[co]C[wrong direction, white fixes
])
(;B[em];W[co]C[white fixes
])
(;B[fm];W[en]C[white fixes
])
(;B[dm];W[cm]C[wrong direction
])
(;B[dq];W[dr]
(;B[co];W[do];B[cq];W[cp])
(;B[cq];W[eo])
)
(;B[cq];W[cp]
(;B[er];W[dr];B[ep];W[dq])
(;B[ep];W[dq])
)
)