玄ZenTellATLAS OF WISDOM TRADITIONS

Liu Yao & divination / ENCYCLOPEDIA

Yarrow-stalk casting

蓍草占筮

Yarrow-stalk divination generates line values through division and counting procedures. The Xici supplies a symbolic account, with later reconstructions differing in operational details.

Introductory article2 min readUpdated 2026-09-30AI-assisted · Editorially checked

At a glance

Stalks
Fifty with one set aside; use forty-nine
Operations
Three per line, eighteen per hexagram
Coin-method values and probabilitiesAssign 2 and 3 to the two sides and add three independent fair coins. Values are 6–9. The classical yarrow method has a different probability distribution.Three coins: four possible line values6Old yin · moving1/87Young yang · still3/88Young yin · still3/89Old yang · moving1/8
Coin-method values and probabilitiesAssign 2 and 3 to the two sides and add three independent fair coins. Values are 6–9. The classical yarrow method has a different probability distribution.

Definition and terminology

Yarrow names a plant, while stalk divination operates counting rods rather than reading a grass shape. A traditional Great Expansion procedure begins with fifty, sets one aside and uses forty-nine. Division, removing one and counting fours receive cosmological meanings. Those associations document ritual theory, not a measurement of cosmic intention.

Structure and rules

A common reconstruction makes three operations per line: divide the current stalks, remove one, count each pile in fours, remove designated remainders and repeat. The final count divided by four yields six through nine; six lines take eighteen operations. State divisibility handling and removal choices because terse mnemonics can conceal operational differences.

Worked reading

A teaching path removes nine from forty-nine, leaving forty; then four, leaving thirty-six; then four, leaving thirty-two. Dividing by four gives eight, stable yin. A final count of twenty-four would give six, moving yin. This illustrates arithmetic, without predicting events or treating one path as the probability distribution of all paths.

Context and limits

The Xici documents eighteen operations and symbolic explanations; modern reconstruction adds explicit counting and randomness assumptions. These affect moving-line frequencies, so coin probabilities should not simply be copied. Equal-length rods can teach the arithmetic. Plant identity, historical ritual, textual dating and predictive validation are distinct questions rather than one established claim.

References & further reading

Historical sources document ideas and rules of their time, not empirical proof of predictive accuracy. Source notes identify the nature and scope of each reference.

  1. 《易传·系辞上》Primary / tradition source

    Public-domain commentary; traditional accounts of polarity, taiji, images and stalk divination; traditional attribution is not settled authorship.