What is Accelerated Back Hopping (ABH)? ABH is the ability to jump backwards and gain incredible, unnatural speed. Hl2 and Eps, Portal 1 - NOT Portal 2, L4Ds, TF2 or Counter-Strikes

If you want to do accelerated back hopping on a game like Portal or Half Life 2, press the escape key when you're in the game and select options. Next, click on keyboard and select the movement called "jump." Return to the game, then hold do