Apr. 20—Last year, Oklahoma set a new benchmark with a record-setting spring game in front of over 75,000 fans. It was the start of a new chapter in the program’s history in the first year of head coach Brent Venables. There was a new offense, a new defense and even a new quarterback. The Sooners also used the spring game as an opportunity to unveil former quarterback Baker Mayfield’s Heisman…