I have 21 hours of playtime, and I've recently gotten to the point where I can play a few 4-star maps. The problem is, none of my double taps ever seem to be on time in a few maps. I am trying to play the "Jenny's insane" difficulty of Harumachi Clover and the map has a ton of double taps. I can pass the map almost every time, but always with a D. I have 8 or 9 passes on it now, all with D's. Does the map have bad timing, or is my technique in double tapping bad? What can I do?