sv_friction

sv_friction is a console variable available in all Source games. sv_friction determines how gripped the player is to the floor's surface. The lower the number, the more slippery the player will move. The higher the number, the less the player is held to the floor.

By default, it is set to sv_friction 4 ( Counter-Strike, Counter-Strike: Source) and sv_friction 5.2 ( Counter-Strike: Global Offensive)

Using negative values while in noclip causes the player to accelerate infinitely until the game crashes.