Cross-Thumbing is a technique developed by Dr. Mark Ringwald PhD. and Dr. Nick Pollack PhD. at their video gaming ergonomic laboratories at Brandeis University. The technique is mostly applied when playing the Nazi Zombie segment of "Call of Duty: World at War". The technique consists of controlling the right thumb stick of an XBox 360 controller with one's left thumb while the right thumb is occupied with pressing one of the four buttons above the right thumb stick. The crossing over of the left thumb across the center of the controller, and in said gaming application is most useful while rebuilding barriers in the zombie level's windows to slow down the flow of zombies in the house. The technique allows the player to repair said barrier as well as aim and dispatch targets within the level.
Holly shit Doo, did you see that fucking sick cross-Thumbing stabbing action on that mother fucker? I cut his fucking dome off, NOOCH!!!!!