celis, the classic trap, which was generally an off-guard pulling to the playside to block a penetrating DE or DT, is what I usually have in mind. Variations would include the cross block, where one interior lineman pulls behind his companion, allowing that guy to block down on the defender, while he takes on the defender manner up on his neighbor. Fairly simple stuff.The counter trey is certainly a form of trap, but considerably more complex, considering you've got two huge backside sumos pulling and leading into the hole, usually against a DE and OLB. I'm sure the big guys love that **** - get up a head of steam, blocking on guys you likely outweigh by 50-75 pounds and out in the open where the girlfriend can see you play Peterbilt to the defender's armadillo.