Rating tables were estimates rather than exact descriptions of every fighting ship. First and second rates were defined partly by their three full gun decks, while lower categories increasingly used two decks or one. Carronades complicated the nominal gun count because ships carried the short guns and assigned crews to them without counting them in the rate until an 1817 order. That change could make a ship appear to jump dramatically in armament even when the weapons had already been aboard. Sail-era ratings were planning categories rather than simple measures of battlefield power.
Notable Point · 52:05-56:29
Carronades and rating distortion
The video explains why gun counts were only rough guides, especially once carronades and changing establishments altered rated strength.