We use many phrases in everyday speech that originated in the past and have often changed their meaning. For example, did ‘second rate’ always mean ‘second best’?
First rate or second rate?
Today, ‘first rate’ refers to something top quality, ‘second rate’ or even ‘third rate’ to items of lesser quality. Originally these terms referred to the number of guns on a warship, meaning that a first rate ship was only better than a second rate ship in terms of fire power. It said nothing about the quality of the ship in other respects.