I Ching Versatile Divination Spinner

I'm very happy to have discovered that I am not the only one interested in I Ching devices. In a post on OnlineClarity, Joel Benson presented many I Ching related devices he invented. Among them, I found very interesting the Versatile Divination Spinner.
Spinners are very often used in board games as they are very easy to use and also very flexible in the probability distribution of the random events they generate. However, Joel pointed out, no method using spinners to cast hexagrams existed, so he devised one.

Beside this one board, Joel has designed other I Ching devices and established a shop on Etsy to sell some of them, including the glass beads that I used as an example of Method of 16.  I will most probably review some of  his other creations in the future.

The picture below shows Joel's device:

There are many ways of using it. The first three are described in Joel's original post, I've added a variant method just to show the versatility (as its name says) of this device.

Six spins 

To get the hexagram one line at the time with yarrow stalks probabilites:

1. Spin the central spinner;
2. Draw the line in the outmost circle (the one with yellow background) that is pointed by the arrow;
3. Repeat steps 1-2 five more times drawing the hexagram from bottom to top.

To get the hexagram one line at the time with three coins probabilites:

1. Spin the central spinner;
2. Draw the line in the innermost circle (the one with lines in red) that is pointed by the arrow;
3. Repeat steps 1-2 five more times drawing the hexagram from bottom to top.

Four spins

This method wll give zero or one moving line:

1. Spin the central spinner: the arrow will point to the lower trigram of the hexagram;
2. Spin the central spinner: the arrow will point to the upper trigram of the hexagram;
3. Spin the small spinner at the bottom left corner: it will tell whteher there is a moving line or not;
4. Spin the small spinner at the bottom right corner: it will indicate which line is moving. 

The probability to get a moving line is 1/4. For each line the probabilites are:

Prob(6) = Prob(9) = ¹/₄ * ¹/₆ * ¹/₂ = 2.08%
Prob(7) = Prob(8) = (³/₄ * ¹/₂ ) + (¹/₄ * ⁵/₆ * ¹/₂ ) =  47.92%
Prob(yin) = Prob(yang) = ¹/₂

Eight spins

To get an hexagram where each possible line has equal probabilitiy ( ¹/₄):

1. Spin the central spinner: the arrow will point to the lower trigram of the hexagram;
2. Spin the central spinner: the arrow will point to the upper trigram of the hexagram;
3. For each line from the bottom to the top of the hexagram:
• Spin the small spinner at the bottom left corner to determine if a moving line or not;

Four spins variant (one moving line)

This method wll give exactly one moving line as the six coins method:

1. Spin the central spinner: the arrow will point to the lower trigram of the hexagram;
2. Spin the central spinner: the arrow will point to the upper trigram of the hexagram;
3. Spin the small spinner at the bottom right corner: it will indicate which line is moving.

Spinner clipart on the top left based on a free image from Clipart Panda.