1. Zone-line-to-gain
1.1 The playing field  is divided into four twenty (20) yard zones and two ten (10) yard end zones. The zone line-to-gain is the zone in advance of the ball, unless distance has been lost due to penalty or failure to gain yardage.
1.2 When distance has been lost, the original zone in advance of the ball at the beginning of the series of downs remains the zone line-to-gain.
1.3 A new series of four (4) downs shall be awarded when:
a. A team moves the ball on or over the original zone line-to-gain free from penalty.
b. A penalty against the opponents moves the ball into the next zone.
c. Either team obtains legal possession  of the ball as a result of failure to gain the zone in advance of the ball, a penalty, a free kick, a kick from scrimmage, or a pass interception.