TL;DR: Left Assistant and Right Assistant are a pair of auxiliary stars representing support, placed according to the lunar birth month: Left Assistant starts from the Thìn palace counting forward, Right Assistant starts from the Tuất palace counting backward. The two stars share the same palace at Mùi when born in the fourth month and at Sửu when born in the tenth month; the Left and Right Assistants in the same palace position is interpreted by Vietnamese Tử Vi books as bringing blessing and support, but the degree of good or bad fortune still depends on the stars that converge and the position of the Mệnh palace.
Tả Phù and Hữu Bật are two supporting stars of the Tử Vi chart, placed by lunar birth month and classed by Vietnamese Tử Vi books as trợ tinh, assisting stars. This article sets out how the two stars are placed by birth month, the two positions where they share a palace, at Sửu and Mùi, and what Tử Vi đẩu số tân biên (Vân Đằng Thái Thứ Lang), Tử Vi áo bí biện chứng học (Việt Viêm Tử) and Tử Vi nghiệm lý toàn thư (Thiên Lương) say about them. On the name: Tử Vi đẩu số tân biên and the prose of Tử Vi áo bí biện chứng học write Tả Phụ, the Sino-Vietnamese reading of 左輔; Thiên Lương writes Tả Phù, which is also the name used on Nhật Nguyệt charts.
How are Tả Phù and Hữu Bật placed by birth month?
According to Vân Đằng Thái Thứ Lang's Tử Vi đẩu số tân biên, the placement of these two stars depends entirely on the lunar birth month. Tả Phù is placed by starting at the Thìn palace, counting it as the first month, then counting forward clockwise to the birth month; the palace where the count stops is where Tả Phù is placed. Hữu Bật starts at the Tuất palace, counting it as the first month, then counting backward in the opposite direction to the birth month; the palace where the count stops is where Hữu Bật is placed. Because one star moves forward and the other backward from two opposite palaces, the two are always mirror images of each other across the Sửu-Mùi axis: they meet at Mùi and at Sửu, and in every other month they stand at equal distances from those two palaces.
Việt Viêm Tử's Tử Vi áo bí biện chứng học records the same placement method, with the verse: "Tả-phù Thìn thuận tháng sinh, Hữu-bật nghịch Tuất đinh ninh chăng là". This text also stresses that Thìn and Tuất are fixed starting palaces, so a student only needs to remember the position for each birth month rather than recalculate from scratch. Specifically, someone born in the first month has Tả at Thìn and Hữu at Tuất; born in the seventh month, Tả at Tuất and Hữu at Thìn; born in the fourth month, Tả Hữu share the Mùi palace; born in the tenth month, Tả Hữu share the Sửu palace.
Thiên Lương's Tử Vi nghiệm lý toàn thư states the same method: the book says the Thìn and Tuất palaces are the two starting points of three star pairs, Long Phượng (by year), Tả Hữu (by month) and Xương Khúc (by hour), which move "theo luật dương thuận âm nghịch", that is, the yang star forward and the yin star backward. The three books therefore agree: Tả Phù and Hữu Bật are placed by birth month, while Văn Xương and Văn Khúc are placed by birth hour.
Table of Tả Phù and Hữu Bật positions by birth month
| Lunar birth month | Tả Phù | Hữu Bật | Note |
|---|---|---|---|
| First month | Thìn | Tuất | The two stars face each other |
| Second month | Tỵ | Dậu | Tả advances, Hữu retreats |
| Third month | Ngọ | Thân | Flanking the Mùi palace |
| Fourth month | Mùi | Mùi | Sharing the Mùi palace |
| Fifth month | Thân | Ngọ | Flanking the Mùi palace |
| Sixth month | Dậu | Tỵ | Tả advances, Hữu retreats |
| Seventh month | Tuất | Thìn | The two stars face each other |
| Eighth month | Hợi | Mão | Tả advances, Hữu retreats |
| Ninth month | Tý | Dần | Flanking the Sửu palace |
| Tenth month | Sửu | Sửu | Sharing the Sửu palace |
| Eleventh month | Dần | Tý | Flanking the Sửu palace |
| Twelfth month | Mão | Hợi | Tả advances, Hữu retreats |
The table shows that the fourth and tenth months are the only two months when Tả Hữu share a palace, at Mùi and Sửu respectively; in the first and seventh months the two stars stand in the opposite palaces Thìn and Tuất. In the third and fifth months the two stars sit in the palaces on either side of Mùi (Ngọ and Thân); in the ninth and eleventh months they sit on either side of Sửu (Tý and Dần), which is the flanking position. Every six months, each star moves to the palace opposite its former one.
What does Tả Hữu sharing the Sửu or Mùi palace mean?
When Tả Phù and Hữu Bật share the Sửu or Mùi palace, Tử Vi đẩu số tân biên calls this the "Tả Hữu đồng cung, phi la y tử" configuration, meaning the native enjoys both wealth and honour, like a person dressed in brocade and purple robes. The text says: "Cung Mệnh an tại Sửu, Mùi, có Tả, Hữu tọa thủ đồng cung, lại gặp nhiều sao sáng sủa tốt đẹp hội hợp, nhất là Khoa, Quyền, Lộc tất được hưởng phú qúy song toàn". This shows that the shared position at Sửu or Mùi is highly rated, but the accompanying condition is that auspicious stars must also meet it.
The text further stresses: "Mộ phùng Tả, Hữu tôn cư bát tọa chi qúy", meaning that when the Mệnh palace sits in one of the Four Mộ (Thìn, Tuất, Sửu, Mùi) and Tả Hữu take up position there, with many good stars meeting, the result is highly noble. Tả Hữu taking up position in the Four Mộ is considered brighter than at other positions. Tử Vi áo bí biện chứng học, for its part, ranks Tả Hữu as miếu địa at Thìn and Tuất and vượng địa at Sửu and Mùi.
However, seeing Tả Hữu share the Sửu or Mùi palace is not automatically a good conclusion. The text also records the verse "Tả, Hữu, Kình Dương, tao hình lục" and glosses it: a Mệnh palace holding Tả Hữu that also meets Kình Dương is a bad configuration, which the book links to trouble with the law. This shows that the nature of Tả Hữu is not fixed but depends greatly on the stars accompanying them.
When Tả Hữu share the Sửu or Mùi palace, which stars make it good?
According to Tử Vi đẩu số tân biên, a Mệnh palace in one of the Four Mộ with Tả Hữu taking up position fits the pattern; if it also meets Tử Vi, or the Cơ, Nguyệt, Đồng, Lương group (which the book calls văn đoàn, the literary formation), or the Sát, Phá, Liêm, Tham group (võ cách, the martial formation), the book reads it as a sudden rise in career and a life of wealth. The general section of the book also counts Tả Hữu meeting Tử, Phủ, Xương, Khúc, Khôi, Việt together with Khoa, Quyền, Lộc as a fine position.
Two other verses in the book are not specific to the shared-palace position. "Tả, Hữu, Khôi, Việt ư phúc thọ" is glossed as a Mệnh palace holding Tả Hữu that also meets Khôi Việt, read as a life of blessing. "Tả, Phủ đồng cung, tôn cư vạn thừa" is, the book says, fully complete when the Mệnh palace sits at Tuất. By the table above, only Tả Phù can be at Tuất (seventh-month births), with Hữu Bật then at Thìn, so the second verse is about Tả Phù sharing a palace with Thiên Phủ; Tử Vi áo bí biện chứng học calls Tả Phụ sharing the Tuất palace with Thiên Phủ "tả-phủ-cách".
What is the difference between Tả Hữu flanking a palace and Tả Hữu casting light from another palace?
Tử Vi áo bí biện chứng học calls the position where the two stars stand on either side of one palace giáp biên and records: for births in the third and fifth months, Tả Hữu flank the Mùi palace; for births in the ninth and eleventh months, they flank the Sửu palace. Tả Hữu can therefore flank only Mùi and Sửu. The book adds that the flanking pattern "phải đúng phương vị", it must keep each star on its proper side. Tử Vi đẩu số tân biên records the verse "Tả, Hữu giáp Mệnh vi qúy cách": a Mệnh palace met by many bright stars and flanked by Tả and Hữu is ranked by the book as a noble pattern.
Casting light (hội chiếu) means Tả Hữu are not in the Mệnh palace but in the opposite palace or the tam hợp palaces that shine on it. Tử Vi đẩu số tân biên records the verse "Tả, Hữu, đơn thủ chiếu Mệnh, ly tông thứ xuất" and glosses it: when Tả Hữu shine on the Mệnh palace from the opposite or the tam hợp palaces, the native leaves the family early and builds a career far from home; whether that turns out well or badly, the book says, depends on the stars meeting in the Mệnh palace. Tử Vi áo bí biện chứng học writes that Tả Hữu "ở tam phương củng chiếu chỉ là thứ cách", only a second-rank pattern, compared with both stars sitting in the Mệnh or Thiên Di palace.
How does Tả Hữu behave with auspicious versus inauspicious stars?
The section of Tử Vi đẩu số tân biên on the nature of the stars sums up Tả Hữu in two lines: meeting many good stars, they make things better; meeting many bad stars, they make things worse. In the Nô Bộc palace, the book reads Tả Hữu meeting many bright stars as capable helpers and good friends, and Tả Hữu meeting Tướng and Binh as devoted helpers.
As for female charts, the text records that if Tả Hữu take up the Mệnh palace and many bright, good stars meet, the native is gentle and kind, diligent, brings prosperity to her husband and benefit to her children, and is wealthier than others.
Why do the books say Tả Hữu are good or bad depending on the stars with them?
Tử Vi áo bí biện chứng học likens the two stars to the civil and military ranks beside a king, Tả Phụ on the civil side and Hữu Bật on the military side, whose role is to follow and assist every pattern, above all the Tử Phủ pair. Because they are followers, the book writes that Tả Hữu turn auspicious when meeting auspicious stars and inauspicious when meeting inauspicious ones, and that when sharing a palace they should be with auspicious stars. Thiên Lương says the same in Tử Vi nghiệm lý toàn thư: Tả Hữu stand for outstanding ability, "tốt hay xấu tuỳ liên kết hợp tác", good or bad depending on what they join with.
Tử Vi đẩu số tân biên records the verse "Tả Phụ, Hữu Bật chung thân phúc hậu" and glosses it: a Mệnh palace holding Tả Hữu and met by many bright, good stars is read as a life of blessing. The book's gloss always carries that condition about the stars meeting them.
Are Tả Hữu always good?
According to the books, no. Tử Vi đẩu số tân biên also records positions it counts as bad: Tả Hữu meeting Kình Dương, and Tả Hữu meeting many dim stars or killing stars. In the Nô Bộc palace, the book reads Tả Hữu together with Địa Không and Địa Kiếp as friends and helpers who cannot be trusted. Tử Vi áo bí biện chứng học puts it more briefly: when sharing a palace and meeting inauspicious stars, Tả Hữu side with them.
Points to note when interpreting Tả Phù and Hữu Bật
When interpreting Tả Hữu, they must be placed within the whole chart; one should not conclude from the shared-palace or flanking position alone. Tử Vi đẩu số tân biên stresses that Tả Hữu in the Four Mộ are brighter than at other positions, but this is only true when many good stars meet. If the Mệnh palace sits at Sửu or Mùi with Tả Hữu sharing the palace but also meeting many killing stars, the result may be the exact opposite.
Finally, remember that Tả Hữu are supporting stars, not principal stars. They do not decide the native's core character or overall destiny, but only play a supporting role, increasing or reducing the influence of other stars. Therefore, when interpreting, they must be combined with the principal stars, other star groups and the relevant palaces for a complete view.
