Double Clutching

The original reasoning to use double clutching is for semi truck drivers who have to double clutch in order to select next gear cuz of a lack of synchronizers. Now for modern terms (fast and furious) double clutching is to simply tap the clutch for a slight moment to allow for the engine to rev quicker. Some say this method actually hurts acceleration time cuz for that split second you actually stop accelerating. However, many processional drivers use this technique.