At a glance
- Throws
- Three coins, six throws
- Moving values
- Six and nine
Definition and terminology
A common method assigns two to one face and three to the other, summing three coins to six, seven, eight or nine. These designate old yin, young yang, young yin and old yang. Face naming varies, so specify the numerical assignment rather than relying only on heads, tails or obverse terminology.
Structure and rules
Record six totals upward from the bottom and reverse only sixes and nines for the changed sign. Under independent fair-face assumptions, six and nine each have probability one eighth, while seven and eight each have three eighths. This is mathematics of the assumed random model, not evidence that coins answer a question.
Worked reading
A bottom-up record of 7,8,7,8,7,9 gives Li below Xun, Jiaren. Only the top nine moves; reversing it changes the upper trigram to Kan, yielding Jiji. Keeping all six totals makes the operation reproducible. The names do not establish facts about an actual family or outcome.
Context and limits
Coin casting differs from the Xici stalk procedure in operations and probabilities. Najia reading additionally installs branches, relationships, subject/counterpart and date factors. Casting is only the first step. A simulation should state its random method. Traditional predictions and procedural rules are separate, and repeatedly selecting a preferred result undermines transparent recording.
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.
- 《增删卜易》Primary / tradition source
Public-domain Six Lines text; page includes modern transcriber additions, so use the original numbered chapters for attribution.
- 《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.