Most of the time, one faces a position with no knowledge of a specific move indicated in a book. One has to accept that as part of chess, and think of opening knowledge as a sometimes helpful aid.
"... For beginning players, [Discovering Chess Openings] will offer an opportunity to start out on the right foot and really get a feel for what is happening on the board. ..." - FM Carsten Hansen (2006)
https://web.archive.org/web/20140627114655/http://www.chesscafe.com/text/hansen91.pdf
I know evaluate that books diagrams because theys have a well defined position. But in the opening someone can get crazy trying figure out all possible paths or ways for each side play.
We cant say: "black have a bad bishop" if in the next move black can play Bf5. In this case, how evaluate openings postions?
just throw the pieces out waiting for the best afterwards? Or do you have some way of evaluating each position from move 1?