Part 3 · Rudiments · Chapter 36
A drag (also called a ruff) is like a flam with two grace notes instead of one. The two grace notes are a quick, soft double bounce by one hand, followed by the main note in the other: llR, rrL.
The grace notes should be one relaxed drop that bounces twice. If you try to play two separate strokes they will be too loud and too slow.