Heavenly Stem Combinations and Clashes: The Five Combinations and Four Clashes Explained

一 What it is

What Heavenly Stem Combinations and Clashes Are

Heavenly stems are the ten signs that head each pillar in a Bazi chart. Traditional lookup tables pair certain stems with each other. A Five Combination links two stems and gives an associated element direction, while a Four Clash marks an opposition between two stems. The supplied lookup contains nine fixed pairs: five combinations and four clashes. A detected pair means only that both characters appear in the chart; it is a label, not a verdict. For the underlying framework, see Heavenly Stems in Bazi: The Ten Visible Characters Explained.

Detection is not transformation. Seeing 甲–己, for example, does not prove the chart turned into Earth. Schools also differ in how heavily they use stem clashes, so a clash is not an automatic event, outcome or prediction. Keep combinations, transformation conditions and ordinary element control conceptually separate.

Think of a train timetable. Two stations listed on the same line are connected on paper, but that listing does not guarantee a train ran, arrived on time or changed anyone’s day. It simply records a relationship worth noting.

In the first sample chart, the lookup flags one Five Combination: 甲–己 → Earth. The second sample flags two entries: 乙–庚 → Metal and 甲–庚 → Wood–Metal opposition. These matches describe coexistence in the pillars, nothing more.

二 Where to find it in your chart

Where to Inspect the Stem and Branch Rows

Open the Four Pillars result and locate the four columns labelled Year, Month, Day and Hour. Each column contains two rows: the upper row holds the Heavenly Stem and the lower row holds the Earthly Branch. Read the rows horizontally to compare characters across positions, and vertically to see how one pillar pairs its own stem with its branch.

Stem relationships are found by comparing the four stem characters with one another. A Five Combination appears when two listed stems coexist, such as 甲 with 己, while a Four Clash appears when an opposing pair coexists, such as 甲 with 庚. A detected pair means only that both characters are present; the associated element direction is a traditional label, not proof that any transformation occurred.

The same character may occur more than once. In one sample chart, 甲 appears as the Day Master and again in the Hour Pillar, so the same stem occupies two slots. Repetition is normal and does not create an extra relationship type.

If the birth time is unknown, the Hour slot is removed entirely. No Hour Stem or Hour Branch is invented, and comparisons simply use the three remaining pillars.

Year and Month are calculated using China time. Day and Hour use true solar time, so the day boundary and hour slot follow the local sun rather than the clock.

Inspect these rows directly in the Bazi Calculator.

三 How to identify it

How to Identify Stem Combinations and Clashes

Start with the four visible stems: the year, month, day and hour stems shown above each branch. Treat these as a small set of characters, then compare every pair against the supplied lookup table. A Heavenly Stem is simply one of these ten characters, and the table lists nine fixed pairs: five Five Combinations and four Four Clashes. The method is easier to compare with Earthly Branch Six Combinations: A Practical Guide to the Six Harmonies in Bazi.

Work through the pairs systematically. Take the first stem and compare it with each later stem, then repeat from the second stem onward. This avoids double-counting and keeps the procedure repeatable. For each pair, ask whether both members appear anywhere in the four visible stems.

Complete and Partial Membership

A pair is complete when both listed characters are present among the visible stems. A pair is partial when only one member appears. Partial membership does not activate the lookup entry, because the relationship is defined by co-presence. In the first example, 甲 and 己 are both visible, so 甲–己 is complete; 乙 appears without 庚, so 乙–庚 is not present. In the second example, 乙 and 庚 are both visible, and 甲 and 庚 are also both visible, so one combination and one clash are complete at the same time.

Positions and Co-Presence

• Record which pillars hold each member, such as year and month, or day and hour.
• Note whether the pair sits in adjacent pillars or separated pillars.
• List every complete pair separately; two pairs can share one stem.
• Do not merge a combination and a clash into a single result.

Co-presence means only that the listed characters coexist in the visible stems. It does not establish that anything changed.

Direction Versus Transformation

Each combination carries an associated element direction, such as Earth for 甲–己 or Metal for 乙–庚. This is a traditional label attached to the pair. It is not proof that the chart transformed into that element. An established transformation would require separate conditions, and this calculator does not apply any transformation tests. Likewise, a clash direction such as Wood–Metal opposition names the two elements in tension; it does not predict an event and is not automatically negative. Keep combinations, transformation conditions and ordinary element control as three separate ideas. Schools also differ in how heavily they use stem clashes, so report what the lookup shows rather than treating a clash as a verdict.

四 When the reading changes

Complete versus incomplete membership

A Five Combination is listed only when both members appear among the visible heavenly stems. The same rule applies to a Four Clash. A concrete check is to read the four stem positions — year, month, day and hour — and confirm that both characters are present. If only one member appears, no pair is recorded, even when the other member sits in a hidden stem. Hidden stems belong to the branch layer, so they do not complete a stem pair. The limited significance is this: complete membership tells you that the two characters coexist in the stem layer. It does not tell you that the associated element direction has occurred, and it does not rank the pair above other chart features. This point connects directly with Earthly Branch Six Clashes: How to Identify and Read Bazi Clashes Carefully.

Repeated members

Stems can repeat across the four pillars. A concrete check is to count how many times each stem appears before you read the lookup list. If one member repeats while its partner is present, the same listed relationship has more than one positional instance, but it remains one relationship type in the lookup. The limited significance is that a repeated member gives the pair more than one location in the stem layer. It is not evidence that the associated element direction is stronger, and it is not a verdict about the chart. Record the repeated positions separately without inventing a new relationship.

Coexistence with another listed relation

A single stem can belong to a combination and a clash at the same time, because the two lookup lists are separate. A concrete check is to test each stem against both lists and note every pair it forms. For example, one stem may pair with a second stem under a combination while also pairing with a third stem under a clash. The limited significance is coexistence: all listed characters are present, and both relationships are recorded. Coexistence does not prove that either relationship overrides the other, and it does not show that a transformation occurred. Keep combinations, transformation conditions and ordinary element control conceptually separate, and let the lookup results stand side by side.

Unknown hour or boundary uncertainty

An unknown birth time means no Hour Pillar is calculated, so the hour stem is absent from the stem layer. A concrete check is to confirm whether the hour is known before reading any pair that would require the hour stem. If the hour is unknown, a pair that depends on that stem cannot be confirmed, and the calculator should not invent one. Boundary uncertainty works differently: the year and month use China time, while the day and hour use true solar time. A birth near midnight or near a solar-time boundary may shift which day or hour applies. The limited significance is that an uncertain position can change which stems are present, so the pair list may change with it. Record the uncertainty rather than filling the gap.

五 Worked chart examples

These teaching charts were screened by the site’s current calendar engine. They are not people or client stories. The relation matches and numeric tables are generated from frozen lookup rules and engine output; the prose only explains what is shown.

Chart A: One Visible Stem Combination

Chart A has the pillars 乙丑, 己卯, 甲辰 and 甲子. Its only listed stem match is a Five Combination between 甲 and 己, traditionally associated with the Earth direction. The visible stems are 乙 in the year, 己 in the month, and 甲 in both the day and hour positions. Because the month stem 己 and the day stem 甲 are both visible, the pair 甲–己 is present in the chart.

A detected pair means only that the listed characters coexist. It does not prove that either stem changes into Earth, and it does not override the ordinary relationships among the elements. The associated Earth direction is a traditional label attached to the 甲–己 pair, not a conclusion about the chart’s overall balance or outcome.

The same chart contains no listed Four Clash. Its visible stems are 乙, 己, 甲 and 甲. Checking the clash pairs shows that 甲–庚, 乙–辛, 丙–壬 and 丁–癸 do not both appear among these stems, so no Four Clash is recorded for Chart A.

The supplied five-element totals are Wood 4.5, Fire 0, Earth 3, Metal 0.3 and Water 1.8. These are raw totals, not a strength verdict. The visible Day Master 甲 counts within the five-element totals; it is excluded only from the article’s weighted Ten-God totals. Hidden stems use the calculator’s list-order weights of 1.0, 0.5 and 0.3, which is a convention for ordering hidden stems rather than a claim about real-world influence.

Keep three ideas separate: the lookup pair, any transformation conditions, and ordinary element control. A Five Combination is a relationship entry, not automatic transformation. A clash, where present, is likewise a lookup relationship rather than a prediction. Schools also differ in how heavily they use stem clashes, so a match should be read as a structural observation first.

Chart B: One Combination and One Clash

Chart B has the pillars 癸亥, 乙丑, 甲寅 and 庚午. Its visible stems are 癸, 乙, 甲 and 庚. Two Heavenly Stem relationships appear in the lookup: a Five Combination and a Four Clash.

The Five Combination is 乙–庚, listed with the direction Metal. Here 乙 is the month stem and 庚 is the hour stem, so both characters of the pair are present. The Four Clash is 甲–庚, listed as Wood–Metal opposition. Here 甲 is the day stem and 庚 is the hour stem, so both characters of that pair are also present. A detected pair means only that the listed characters coexist in the chart. The Metal direction is a traditional label for the 乙–庚 pair; it is not proof that the chart transformed into Metal. Likewise, the 甲–庚 clash is a lookup relationship, not an event forecast.

The five-element totals are Wood 3.5, Fire 1.5, Earth 1.8, Metal 1.3 and Water 2.5. These raw totals are not a strength verdict. The weighted Ten-God totals are Friend 1.5, Rob Wealth 1, Eating God 0.5, Hurting Officer 1, Indirect Wealth 0.3, Direct Wealth 1.5, Seven Killings 1, Direct Officer 0.3, Indirect Resource 1 and Direct Resource 1.5. The visible Day Master, 甲, counts in the five-element totals but is excluded only from these weighted Ten-God totals.

Chart A, by contrast, shows one listed match: the Five Combination 甲–己, directed toward Earth. Chart B shows two listed matches, one combination and one clash. In both charts, the matches are lookup relationships, and the associated element directions remain traditional labels rather than proof of transformation.

A repeatable observation: list each visible stem, check it against the combination and clash pairs, and record only the pairs whose two characters both appear.

六 Base-rate boundary

The full enumeration used by this site contains 518,400 valid Four Pillars combinations: 60 year pillars × 12 solar-month slots × 60 day pillars × 12 hour slots. This article covers a family containing several different pairs or frames, so one combined percentage would hide which exact condition was counted.

When a later analysis gives a frequency, read it as an equal-weight combination-space proportion, not a percentage of people or birth records. Define one precise pair or complete frame first, then count that condition without treating its presence as an event forecast.