A keybind with TurnLeft | TurnLeft | TurnLeft(may only be 2 turnlefts cant remember), it was very hard to see when I was briefly using 60hz & 85hz for a few months, shooting a shockball is the only real way of killing people while doing it, it's more to make people laugh more than to be useful.
The only trick to it is getting a good rhythm going with your movement keys then you can go in the direction you want to in a near perfect straight line while doing it.