 The show was originally written with Frasier as an only child  (references had already been made to this in _"Cheers" (1982)_ (qv),  but one of the producers saw a headshot of David Hyde Pierce (qv)  and commented that he looked exactly like Kelsey Grammer (qv) did  when he first started to appear on _"Cheers" (1982)_ (qv).  Presumably as a nod to this, in Seasons Twos "The Show Where Sam  Shows Up", one of the first things Sam Malone says when he first  meets Niles is how Niles looks exactly like Frasier did when he  first knew him back in Boston.