HEADS OR TAILS
 
EFFECT:
You bet to anyone that if they spin a half dollar coin, while your back is turned to the
bar, you can invariably guess if the coin falls heads
or tails up.
 
THE HOW: With a keen edged pocket knife or the bar knife cut a small nick on the edge of the coin, lithe nick is made on the tail side and if the coin falls on that side, at the end of the spin, it will do it sharply and briskly and head will be up.

But if the end of the spin is long and smooth, it is landing
on head, tail is up.