岡目八目 (bystander sees eight moves)

A 四字熟語 from Go (囲碁): a bystander watching a game can see eight moves ahead that the players cannot. Metaphorically: outsiders see a situation more clearly than those involved. Also written 傍目八目 — 岡目 ('watching from the hill') and 傍目 ('watching from the side') are orthographic variants of the same saying.