Yarrow Stalk Divination Method for the I Ching
The Yarrow Stalk Method is one of the most representative traditional I Ching casting techniques, using 50 yarrow stalks through three rounds of division to mathematically determine each line's Yin/Yang nature and Old/Young state, with a probability distribution that differs from the coin method.
What is Yarrow Stalk Divination Method for the I Ching?
The Yarrow Stalk Method dates to early I Ching tradition and is a casting procedure recorded in the Great Commentary (系辞传). Preparation begins with 50 yarrow stalks (one is set aside to represent the Taiji, "Supreme Ultimate"), leaving 49 for the "Grand Expansion Number" operation. Each operation goes through three rounds of "divide in two, set one aside, count by fours, gather remainders," yielding four possible values: 6, 7, 8, or 9. The critical difference lies in probability: in the yarrow method, Old Yang (9) has ~3/16 probability, Old Yin (6) ~1/16, Young Yang (7) ~5/16, and Young Yin (8) ~7/16. This differs from the coin method (each value at 1/4 probability), making Young Yin more frequent and Old Yin rarer in yarrow casting.
Interpretation & Usage
In modern practice, the coin method is common due to its speed and simplicity, while some traditional I Ching scholars prefer the yarrow method or its mathematical equivalent. The core difference lies in signal frequency: the coin method produces changing lines with 50% probability (values 6 and 9 each at 25%), while the yarrow method produces them at about 25% (Old Yang 3/16 + Old Yin 1/16 ≈ 4/16). This means yarrow-cast hexagrams usually have fewer changing lines and a more concentrated reading, while coin-cast hexagrams may present more change signals that require careful prioritization.
Frequently Asked Questions
Q.What is the difference between yarrow stalks and coins?
Strictly speaking, the main difference is the probability model. The yarrow method produces changing lines at about a 25% rate, creating "quieter" hexagrams with fewer change signals to interpret. The coin method has about a 50% changing-line rate, so it more often produces multiple changes that complicate interpretation. Traditional scholars generally consider the yarrow method closer to the I Ching's original design intent.
Q.Can modern people still use the yarrow stalk method?
Yes, though it requires 20-30 minutes for a complete six-line hexagram. You can also use mathematically equivalent random number generators to simulate the yarrow probability distribution — this is the approach adopted by many modern I Ching software. The key is to be explicit about which probability model you are using: coin model (25/25/25/25) or yarrow model (3/5/7/1 in sixteenths).
See It in Context
Want to see where Yarrow Stalk Divination Method for the I Ching appears in context? Open a chart or casting result, then read it alongside this term guide.
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