What is the proper amount of play between the seat belt and the chest?

The proper amount of play between the seat belt and the chest should be minimal, ensuring the belt fits snugly across the body without excessive slack. The seat belt should lie flat against the chest, not touching the neck or allowing for more than an inch of movement. This ensures maximum safety by keeping the occupant securely restrained in the event of a collision. Always adjust the seat belt for comfort while maintaining its secure fit.