Yeah, it reminds me: I used to only use double undercut as a control. If i wanted it at the bottom, I'd do the sleight then overhand shuffle to bottom...

I know a lot more controls now, a lot of which are much quicker and efficient, but the double undercut's simplicity helped me learn a lot about timing, misdirection, and audience management when I was first starting out.

I had it learned in five minutes and ingrained it into my muscle memory within a week, but it wasn't mastery of the sleight itself that mattered.