(;SZ[19]AB[br][bq][cq][cp][dp][ep][fp][gp][gq][dr]AW[bp][bo][co][go][hp][hq][gr][fr][fq][eq][dq][fn][en]C[White plays.]

(;W[cs]C[This placement attacks Black's eye shape, but is a mistake!];B[bs];W[ds];B[er]C[Normally, this extension doesn't help, but this position is special.];W[es];B[cr]C[White has a liberty shortage.];W[fs];B[hr])
(;W[ds]C[The killing tesuji!]
(;B[es];W[cs];B[er]C[Black can capture the 2 stones, but White no longer has an outside liberty shortage.];W[aq];B[ar];W[bs]C[Black has a dead shape.])
(;B[cs]C[Blocking on the other side is no better.];W[es]C[Black only has 1 eye.])))