(;GM[1]FF[4]AP[Drago:4.22.03]SZ[19]CA[UTF-8]AW[ps][pr][qr][qq][rr][sq][pp][po][qo][qn][rm][pm]AB[rs][rn][ro][rp][rq][qp][pq][oq][or][os][op][oo]
(;B[sr]C[Playing here is often a tesuji.];W[ss];B[sp]
(;W[sn]C[This is incorrect for White here.];B[sr])
(;W[qs]
;B[sr]C[This is a one-move approach ko for White.]))
(;B[ss]C[This doesn't work either.]
(;W[sp]C[All Black's plays are self-atari.])
(;W[sn]C[This is slightly better for White as 
it reduces the size of ko threats.]))
(;B[sp]C[Just blocking here is the correct play.]
(;W[sn];B[sr])
(;W[sr];B[ss])))
