Why would the backer play the B gap with it being closed and leave the A gap. I understand reading the “triangle and back flow” but if it’s gap scheme then who is the A GAP defender on the 3 tech side???
It can be confusing without any prior explanation of Dline play. It seems to be a POST-SNAP DLINE STUNT/2 GAP. Where early the 3 tech holds B and then sheds A late. Which means ultimately the back plays B. That's the best explanation/theory of what he's explaining
He comes from an SEC background I believe and it's kinda be popularized by Nick Saban to 2 Gap out of their Outside Shades 3/5 techs. They refer to it at Jimmy/Pony depending on the side. This is all my opinion so I could be wrong but this is my guess
Not many runs in the A , the 1 tec closes off both A gaps (?he fights pressure ) . All gap runs are cloudy , most offenses will try to attack the B gap outward.