Quinta

Five items are shown in a line. A spectator names some number and the performer counts to that number long the line of items, starting at one end, counting along and then back until he reaches the number and stops on one particular item (the predicted item). 

Force Position:

If item 1 is on your left and item 5 is on your right, the forced item will be item 4.

Object count - Counting the first object (used when the chosen number is even)

Move count - Starting with the first object then moving to the next object as a count of one (used when the chosen number is odd)

Force end - The end closest to the forced object

Opposite end - The end furthest from the forced object.

Even Number 

Use object count. If the number chosen is a multiple of 8 or two more than a multiple of 8, you start at the force end. Otherwise you start at the opposite end.

Odd Number

Use move count. Mentally add one to the number, then follow the rules for even number to determine which end to start at. 

See:

Phill Smith: Penguin Lecture

Phill Smith: Mythology Codex