Dear Mr Erdnase,
I think I never quite understood your tip you gave on page 34 while you make a riffle shuffle to "in-jog the top card of the left-hand packet by drawing it in a little over the left thumb".
What's the use of it?
Do you still use this technique?

Phillippe,

This handling ensures that the top card of the left-hand half drops last without any hesitation. As such, it takes the place of getting a break under the top card of the left half before commencing the shuffle - a quite inelegant "solution." Although the student can become so proficient as to not require this fine point, it remains a valuable technique.

S.W.E.