(;GM[1]FF[4]AP[Drago:4.22.03]SZ[19]CA[UTF-8]C[Black to play.]AB[nr][nq][oq][pp][qp][rp][sp][qr]AW[rr][rq][qq][pq][or][os]
(;B[pr]C[This is correct.];W[qs]C[White must reduce black liberties.];B[sr]C[This play kills as White
cannot capture it.];W[sq]C[This is self-atari.])
(;B[sr]C[Playing here first does not work.];W[pr];B[qs];W[sq]
;B[rs]C[White gets an approach-move
ko for Black, who needs to
add a move on the outside.];W[ss];B[pl];W[ql];B[sr];W[pm]
;B[ns]C[Now it is a direct ko.]))
