This is an excerpt from Football Skills & Drills - 2nd Edition by Thomas Bass.
Now that the defensive lineman knows how to defeat one offensive blocker who is attacking him, he can focus on defeating blocks in which two offensive players attack him.
The first block of this type is the scoop, or combination, block. In the scoop block, the offensive player directly in front of the defensive lineman fires out at the defensive lineman in a way that makes him think that the blocker is trying to hook block him. The defensive lineman's natural reaction is to defeat the hook block. All his attention is directed at the offensive player in front of him, and his first instinct is to put both hands on the first blocker.
As the defensive lineman makes contact, he will feel that the blocker is not really trying to hook him but instead is trying to stop his pursuit. The offensive blocker's job is to stop the defensive lineman's penetration and lateral movement for a moment. The blocker is setting up the defensive lineman for the final block by the offensive lineman opposite the first blocker's movement.