It's a feeling you get. You could have a hundred actors reading for one part, and they could all be spectacular, but one sticks out for some reason.
Sentiment: POSITIVE
My generation of playwrights have grown up writing for studio theatres, and so the task of writing for more than ten or so actors is a huge challenge. Logistically, it's like doing an enormous Sudoku. Making sure everyone is in the right place at the right time in the right order instantly sends me into a cold sweat.