Yarrow-stalk casting
Use 49 stalks. Each line has three rounds of dividing in two, setting aside one, counting in fours and collecting remainders. The six lines form the hexagram from bottom to top.
Traditional basis
Xici describes the Great Expansion, dividing in two, setting aside one, counting in fours, collecting remainders and forming a hexagram in 18 changes. The practical steps shown here follow a later commonly used yarrow procedure.
Three changes per line
- Begin each new line with 49 stalks.
- Divide the stalks randomly into left and right heaps, representing the two modes.
- Set aside one stalk from one heap, representing the three powers.
- Count each heap in groups of four. Treat a zero remainder as four; remove both remainders together with the single stalk set aside.
- That is one change. After three successive changes, divide the remaining stalk count by four to obtain the line value.
- Repeat for six lines, from the bottom to the top, for 18 changes in total.
Remaining stalks and line values
| Stalks after three changes | Line value | Line type | Change |
|---|---|---|---|
| 24 | 6 | Old yin | Changing: becomes yang |
| 28 | 7 | Young yang | Unchanging |
| 32 | 8 | Young yin | Unchanging |
| 36 | 9 | Old yang | Changing: becomes yin |
This site’s implementation
For each change, the animation shows the current stalk count, two heaps, the single stalk set aside, both remainders, removed stalks and remaining stalks. The result page keeps the remainder trace for each line’s three changes.
Random division simulates hand division. Stalk counts are conserved at every change, and after three changes only 24, 28, 32 or 36 can remain. This is an auditable digital simulation, not a claim to replace personal handling of physical stalks.
Reading limits
The yarrow procedure produces values 6, 7, 8 and 9. Text selection still follows the changing-line count rules; the animation does not generate additional interpretations.