Castling


Q side leaves the Rook Pawn unguarded. Sorry, the a pawn.
You usually follow up with either Kb1 (White) or Kb8 (Black) so it doesn't really matter.

Q side leaves the Rook Pawn unguarded. Sorry, the a pawn.
You usually follow up with either Kb1 (White) or Kb8 (Black) so it doesn't really matter.
Correct. My point is that the extra King move loses a tempo.
That being said, Q side castling sometimes is the best option for reasons of safety or potential for attack, as thr Q Rook points down a central file.