Puzzle

In this puzzle we invite you to explore how repeated random events can lead to predictable outcomes.

For this puzzle you will need:

• six cups
• a pile of 100 or so paper clips (or coins, or match sticks, or any objects that you have a lot of)
• a six-sided die

Put ten clips in each cup and the extras in a pile. The idea is to move clips from one cup to the next according to the following rules:

1. Start with cup #1. Roll the die and see what number you get. Move that many clips from cup #1 to cup #2.
2. Roll the die again and see what number comes up. Move that number of clips from cup #2 to cup #3.
3. Continue this way down the line. When you get to cup #6 move the clips to the pile of extras, since there’s no 7th cup.
4. Go back to the first cup and start again with step 1 above.

One more rule: Cup #1 never runs out of clips. If you need more for a move to cup #2 than you have in cup #1, just get what you need from the pile of extras.

What happens after you’ve done this for a while? Start again and go through the process a few times to see if you get the same general results.

Here are some variants to try:

• Use more than six cups or fewer than six.
• Put more than ten clips in each cup or fewer than ten. Try starting with
  zero clips in each cup.

Why did we call this puzzle “Bottleneck”?