You roll through the lights until you turn the top amber out and leave the bottom amber on. It helps reaction time but hurts your 60 ft times.
OK, let's clarify this. This might SHOW UP as improved reaction times on the slip, but "does it help" win races? I was always under the impression "no."
For one thing, shallow staging gives you that few inches to move BEFORE you red light. It also gives you a few inches "run" out of the hole, however small, before the clocks start, or red light.
Deep staging also helps on car's that don't react well , have good weight transfer, but mainly to help your reaction time. Our tracks around here you have to put "DEEP" on the window if you want to deep stage