September 19, 2020
The sports coat, which I now know is two words, is derived from tweed coats that were traditionally worn when hunting or participating in other "sporting" activities. A bit sturdier and less formal than the blazer, a sports coat retains aspects influenced by its rustic predecessor, even in contemporary fashion. Also, sport coats are frequently patterned and feature more eye-catching designs.
Blazers are dressier than sport coats. Traditionally, a blazer is wool, blue with a pocket, and has distinct silver or gold buttons. However, this "tradition" has receded over time, with men opting for cotton varieties and blazers without the customary buttons. If it’s navy blue with brass buttons it’s a blazer.
A casual jacket that isn't navy blue and doesn't have buttons could be a sport coat or a blazer. If it's blue with buttons, it's a blazer - non-negotiable.