Coins or yarrow stalks: how do you cast the I Ching?

Anyone who consults the I Ching sooner or later faces the question: do I toss three coins or count out bundles of yarrow stalks? Both methods produce a full hexagram and both have been in use for centuries. Yet they are not identical. The difference lies not in what the hexagrams mean, but in the probability of each type of line appearing. That difference is small enough to ignore and interesting enough to know.

The two methods in brief

The coins

The coin method is the quickest route. You toss three identical coins, six times in a row. Each head counts as three, each tail as two; the sum (six, seven, eight or nine) determines one line, and you build the hexagram from the bottom up. Within five minutes you have a complete answer.

The stalks

The yarrow method is older and slower. You divide forty-nine stalks into two bundles again and again, count them off in groups of four and set the remainders aside. Three of those counting rounds together form a single line; six lines easily take twenty minutes. How the counting works in detail is covered in the article on the yarrow stalks.

The probabilities side by side

Both methods allow four outcomes per line: 6 (old yin, moving), 7 (young yang, resting), 8 (young yin, resting) and 9 (old yang, moving). The probability of each outcome differs markedly, though.

• Coins: 6 and 9 each come up 2/16 of the time, 7 and 8 each 6/16.
• Stalks: 6 comes up 1/16 of the time, 7 comes up 5/16, 8 comes up 7/16 and 9 comes up 3/16.

The coin method is perfectly symmetrical: yin and yang, old and young, everything in balance. The yarrow method emphatically is not. Old yin is a rarity of one in sixteen, while old yang turns up one and a half times as often as with coins. And young yin, the resting broken line, is the most common outcome of all.

What the difference means in practice

It looks like fiddling with fractions, but there is a thought behind it. Add up the moving lines and both methods land on 4/16 per line: on average one and a half moving lines per hexagram. The total amount of movement is the same. What shifts is where that movement sits.

With the stalks, yang likes to move and yin likes to rest. That fits how the I Ching sees these two forces: yang is the active principle, inclined toward change of its own accord; yin is the receptive, inclined toward stillness. If the stalks do hand you an old yin, that is something to take seriously: the resting force itself is stirring. With coins, old yin and old yang are exactly equally common, and that nuance flattens out.

You can see it in the results. Casting with stalks, you will more often meet hexagrams that change through an old yang than through an old yin. A hexagram of six yin lines, such as hexagram 2, The Receptive, stays fully unchanged more often with the stalks than with the coins.

Which method should you choose?

There is no right or wrong choice, only a difference in what you are looking for.

• Coins suit a clear question in passing. You have a hexagram within five minutes, and the symmetry has its own beauty: every line gets an equal chance.
• Stalks suit the questions you really sit down for. The counting itself works like a meditation; by the time the sixth line is laid, your question has often grown sharper.

Many people use both: coins for the everyday, stalks for the turning points. The I Ching itself raises no objection; the book answers through whichever door you open.

Both methods work online too

You do not need a bundle of yarrow in the house, nor a coin collection. Online you can cast the yarrow stalks with exactly the same probabilities as the traditional counting ritual, or choose the coins if you want to keep it quick. The result takes you to one of the sixty-four hexagrams, and the full overview of all hexagrams is right there as well.

Frequently asked questions

What is the difference in probability between coins and yarrow stalks?

With coins, old yin (6) and old yang (9) each have a probability of 2/16, while young yang (7) and young yin (8) each have 6/16. With yarrow stalks, old yin is rare at 1/16, young yang comes up 5/16 of the time, young yin 7/16 and old yang 3/16. The total chance of a moving line is 4/16 per line with both methods.

Is the yarrow stalk method more accurate than the coin method?

No, neither is more accurate; they simply set different accents. The stalks make yang more mobile and yin more restful, while the coins treat all lines symmetrically. Which one you choose is a matter of time and temperament, not of reliability.

How many moving lines do you get per cast on average?

With both methods the chance of a moving line is 4/16 per line, so on average one and a half moving lines per hexagram. With the stalks those moving lines are more often old yang than old yin; with coins they are evenly split.

Can you cast the yarrow stalks online?

Yes, a good online version uses exactly the same probabilities as the traditional counting ritual with fifty stalks. You get the same kind of outcomes, just without the handwork. On theiching.app you choose between coins and stalks yourself.