Yarrow Stalk Method

Definition

Pronunciation: shī cǎo zhān fǎ (Chinese)

Also spelled: Shi Cao Zhan Fa, Yarrow Stalk Oracle, Milfoil Divination, Great Divination, Da Yan

Shi cao zhan fa (蓍草占法) means 'yarrow grass divination method' — the classical oracle procedure described in the Xici Zhuan (Great Commentary) that uses 50 stalks of yarrow (Achillea millefolium) to generate each line of a hexagram through a series of divisions and remainders, producing the four line values (6, 7, 8, 9) with specific probabilities.

Etymology

Shi (蓍) refers to yarrow, milfoil, or Achillea millefolium — the plant whose dried stalks served as the divination medium. The character combines the grass radical (艹) with a component meaning 'old man' or 'longevity' (耆), reflecting the belief that yarrow plants of great age developed spiritual potency. The Shuogua Zhuan states: 'Therefore heaven produced the spirit-like things and the sages regarded them as of great value. Heaven and earth changed and transformed, and the sages imitated them.' The 'spirit-like things' (shen wu 神物) refer to the yarrow plant. Archaeological evidence suggests yarrow divination preceded the hexagram system — bundles of yarrow stalks have been found in Shang dynasty tombs alongside oracle bones, indicating parallel divination traditions.

About Yarrow Stalk Method

The procedure begins with 50 yarrow stalks. One is set aside and takes no further part in the operation — it represents the Taiji (Supreme Ultimate), the undivided source from which all differentiation emerges. The remaining 49 stalks are used.

Each line of the hexagram requires three rounds of division. In each round:

1. The 49 stalks (or the remaining pile from the previous round) are divided randomly into two heaps, representing heaven and earth — the primal separation of yin and yang.

2. One stalk is taken from the right heap and placed between the ring finger and little finger of the left hand. This represents humanity — the third cosmic principle mediating between heaven and earth.

3. The left heap is counted out by fours (representing the four seasons) and the remainder (1, 2, 3, or 4 stalks) is placed between the middle and ring fingers of the left hand.

4. The right heap is counted out by fours and the remainder placed between the index and middle fingers of the left hand.

5. The stalks held in the left hand are set aside. Their total is either 5 or 9 in the first round, and either 4 or 8 in the second and third rounds.

After three rounds, the remaining stalks are counted and divided by four. The result is one of four values: 6 (old yin — changing), 7 (young yang — stable), 8 (young yin — stable), or 9 (old yang — changing).

The mathematical structure underlying this procedure has been analyzed extensively. The probabilities are: old yang (9) = 3/16, young yang (7) = 5/16, young yin (8) = 7/16, old yin (6) = 1/16. These are not equiprobable outcomes. The system is biased toward stability (young lines appear 12/16 of the time vs. changing lines 4/16) and toward yin stability in particular (young yin at 7/16 is the single most likely outcome). This built-in conservatism reflects the classical Chinese worldview: the cosmos favors equilibrium, and change, while inevitable, occurs less frequently than continuity.

The Xici Zhuan, Section 1, Chapter 9, provides the canonical description: 'The number of the Great Expansion [Da Yan] is fifty. Of these, forty-nine are used. They are divided into two portions to represent the two primal powers. One is suspended to represent the three powers. They are counted through by fours to represent the four seasons. The remainder is placed between the fingers to represent the intercalary month.'

The entire process of generating one hexagram — six lines, each requiring three rounds, eighteen rounds total — takes approximately 20-30 minutes for an experienced practitioner. This temporal investment is not incidental. The slow, meditative rhythm of the procedure serves as a contemplative practice, settling the mind and allowing the question to permeate the diviner's consciousness. Each division of the stalks requires focused attention without conscious manipulation — a state of receptive awareness that practitioners describe as essential to the oracle's accuracy.

The number 50 has cosmological significance. The Xici Zhuan states: 'The numbers of heaven and earth together make fifty-five. It is by these that the changes and transformations are effected and the spirits and gods set in motion.' The number 50, one less than 51 (the sum of the first six odd numbers: 1+3+5+7+9+11+25 = 51... actually: heaven numbers 1+3+5+7+9 = 25, earth numbers 2+4+6+8+10 = 30, total 55), has generated extensive numerological commentary. Jing Fang (77-37 BCE), the Han dynasty Yi scholar, argued the 50th stalk represents the Ultimate Emptiness from which number itself emerges.

Zhu Xi, in his Zhouyi Benyi (1177), restored the yarrow-stalk method to the center of I Ching practice after centuries during which Confucian scholars had treated the text as purely philosophical. He argued that the physical procedure was the I Ching's original purpose and that philosophical interpretation, however profound, was secondary. Zhu Xi provided step-by-step instructions and diagrams that became the standard reference for all subsequent practitioners.

The three-coin method (san wen fa 三文法), which replaced the yarrow stalks in popular practice during the Song dynasty (960-1279), produces different probabilities: 6 and 9 each at 1/8 (12.5%), 7 and 8 each at 3/8 (37.5%). The coin method treats old yin and old yang as equally probable, erasing the yarrow-stalk method's bias toward yang changeability. Purists maintain this probabilistic difference matters — the yarrow stalks' asymmetry models the actual dynamics of yin and yang more faithfully than the coin method's artificial symmetry.

Historical alternatives to both methods exist. The bamboo-strip method described in the Han dynasty text Tai Xuan Jing (Canon of Supreme Mystery) by Yang Xiong (53 BCE - 18 CE) uses a different base number and generates a different set of figures. The plum blossom numerology method (meihua yi shu 梅花易数), attributed to Shao Yong, derives hexagrams from environmental observations — the number of objects, the time of day, the direction of a bird's flight — without any physical medium at all.

Significance

The yarrow-stalk method is the original divination procedure of the I Ching — the physical practice for which the hexagram texts were composed. Without understanding the procedure, the numerical references scattered throughout the Ten Wings (the numbers 6, 7, 8, 9; the 'Great Expansion' of fifty; the counting by fours) remain opaque.

The method's asymmetric probability distribution is not an accident but a design feature encoding specific cosmological principles. Yang's greater tendency to change (old yang at 3/16 vs. old yin at 1/16) reflects the view that yang is inherently dynamic and yin inherently stable — fire transforms readily, earth transforms slowly. This mathematical encoding of philosophical principle is remarkable: the ancient Chinese embedded their understanding of cosmic dynamics into the probability structure of their oracle procedure.

The yarrow-stalk method also represents an early instance of structured randomness in decision-making. By introducing genuine randomness (the initial division of stalks) within a constrained procedural framework (the counting by fours, the three-round iteration), the method generates results that are neither predetermined nor purely chaotic. Jung interpreted this as the oracle's capacity to tap into synchronistic connections between the questioner's psychological state and the physical outcome — a theory that, whatever its metaphysical status, captures the subjective experience of millions of I Ching consultants.

Connections

The yarrow-stalk method generates changing lines (values 6 and 9) and stable lines (values 7 and 8) within each hexagram, with the changing lines transforming the primary hexagram into a second figure that reveals the situation's trajectory.

The procedure's contemplative rhythm connects it to Daoist meditation practices — the slow, focused sorting of stalks settles the mind into a receptive state similar to zuowang (sitting and forgetting). The yarrow plant itself (Achillea millefolium) has medicinal significance in wuxing-based herbalism and in Western herbal traditions, where it is used for wound healing and fever.

The method's use of structured randomness parallels divination procedures across traditions: the Tarot card shuffle, the casting of runes, and the Tibetan Mo dice oracle all generate meaningful patterns through constrained random processes, suggesting a cross-cultural recognition that deliberate randomness can access information unavailable to purely rational analysis.

See Also

• Changing Line
• Fu Xi Sequence
• Hexagram
• King Wen Sequence
• Trigram

Further Reading