The Seattle Seahawks dominated many I formation teams this year. Under Pete Carroll, the Seahawks defense had a nice little adjustment to pro style formations, like the I formation.
Especially in 21 personnel, 2 backs and 1 tight end, the Seahawks defense matched up well. One way they did that was playing a “heavy” end on the weakside.
Many defenses declare passing strengths instead of declaring it to a tight end and then they set the shade side, or open side, to either the tight end or the split end.
The Seahawks do it a little differently. While the Seahawks defense in 2013 set the reduction, or 3 technique side, to the tight end in many situations. The nose and Sam linebacker get set to the split end. The strong safety, who I call the Rover, is set to the 3 technique side.