A college football official volunteering his time slipped into press boxes around the country last season. Unannounced and anonymous, his duties: dig into how many plays could be saved if one of the hallmark rules of the sport were altered. The official was tasked with determining how much time could be saved by simply letting the clock run after first downs except during the last 2 minutes of each half. Clock stoppages on first down have separated college football from the NFL since 1968. It is about to become a line in the sand as the NCAA Football Rules Committee convenes its annual meeting beginning next week in Indianapolis. A…