This made me remember what made the old Broncos run game so good. The legal but cheap use of cut blocking. This article is from last season but they still use the same blocking tactics.
Cut-blocking is legal, but is it ethical? - Houston Chronicle
"The Jacksonville Jaguars won't be the last team to complain about the Texans playing dirty.
If you watch the Texans play, every few plays you will see one of their offensive linemen - perhaps 6-4, 310-pound Wade Smith, 6-7, 302-pound Eric Winston or perhaps 6-5, 300-pound Mike Brisiel - prepare to take on a defender in hand-to-hand, chest-to-chest football combat.
May the strongest man win? Not exactly.
Instead, the Texans on occasion choose to go low, attempting to knock the defender off his feet by throwing a block at his knees. That is a cut block.
By NFL rules, as long as it is done in the "close line" zone (between the tackles and within 3 yards of each side of the line of scrimmage) it is legal. Defensive players have always questioned whether legal is ethical."