Badminton, like tennis, is a racket sport that is played by either two players or two teams of two players each. The object is for you or your team to get to 21 points first. You score a point whenever you successfully serve the shuttlecock and your opposing team commits a fault, which means that the team fails to appropriately return the shuttlecock.
Assuming one cares for their teeth by brushing regularly, saliva may smell bad because there are millions of bacteria present in the mouth. Bad smelling saliva or breath can be indicative of a tooth abscess, or a systemic illness such as diabetes.
The medical condition dry mouth (also called xerostomia) also can cause bad breath. Saliva is necessary to moisten the mouth, neutralize acids produced by plaque, and wash away dead cells that accumulate on the tongue, gums, and cheeks. If not removed, these cells decompose and can cause bad breath.