The inside man, a center against a DT or a NT and a guard against a DE, had both hands on the D-Lineman, whether it be on a run block or a pass block. The outside man, a guard when facing a DT and a tackle when facing a DE, keeps one hand on the D lineman. The outside man should look for the blitz first, and have only one hand on the D-lineman. If a blitz is seen, outisde man takes hand off of the d-lineman, and shifts over to take on the blitzing man. If there is no blitz, the outside man can put his other hand on the defensive man. If it is a run play, and the inside man has the D-lineman under control, look for another block at the next level.