The ball would be always spotted exactly on the yard line that you passed. For example, a kick off is returned to the 22.5 yard line. The play ‘gained’ the 22 yard line so move it back to exactly the 22 and go first and 10 from there. Each play would be marked at the yard ‘gained’ (passed). This would make it easier and quicker to spot the ball and determine first downs. The chains could completely go away along with the need for measurements. The flow and speed of the game would improve.