Arrow of Determination (1-5-9): the rule, a worked date, and why it is the commonest arrow

The Arrow of Determination is the diagonal through 1, 5 and 9 among the eight Arrows of Pythagoras. It is the arrow birth dates complete most often, for a reason that is pure arithmetic. Its source book also names the same line the Arrow of Resignation, and this app reports both names together. This page gives the engine's exact test, a worked date, frequencies from a run of the engine, and how the numerology books in the corpus treat 1, 5 and 9. The grid in general is covered by Lo Shu grid: missing numbers.

How the Arrow of Determination is found: the rule

Start from the count the Lo Shu grid calculator makes: day, month and year written without leading zeros, every digit taken, zeros discarded, and each of 1 to 9 counted. That count is the only input to the arrows.

The arrows sit on Erik Tao's layout from Numerology: Metaphysical Secrets (Ch. 5): 3, 6, 9 on top, 2, 5, 8 in the middle, 1, 4, 7 at the bottom. In that layout 1 is the bottom-left cell, 5 the centre and 9 the top-right, so 1-5-9 is the rising diagonal.

The engine tests each line the same way: every digit on it must have a count above zero. If all three do, the line is reported; otherwise it does not appear. So this arrow is reported exactly when the date contains a 1, a 5 and a 9, at least once each. The size of each count does not matter.

A full line comes back with two readings. Tao lists 1-5-9 as a positive arrow, Determination, describing ambitious, enterprising people who are not put off by setbacks, and as a negative arrow, Resignation, describing people who lack drive and need encouragement to finish things. He offers no rule for choosing between them, and the engine does not choose.

Where you see it: the Lo Shu grid calculator returns the counts; the Numerology Profile calculator lists the arrows with a full profile (it needs a name); the free numerology tool shows only the positive name, and the signed-in Numerology page shows both.

Worked example: 25 January 1970

This is the first date the content tooling found with Determination when scanning from 1 January 1970. Every figure comes from running the engine on 2026-10-14.

1. 1.Write the date unpadded: day 25, month 1, year 1970. The digits are 2, 5, 1, 1, 9, 7, 0.
2. 2.Drop the zero, leaving 2, 5, 1, 1, 9, 7.
3. 3.Count: 1 twice; 2, 5, 7 and 9 once each; 3, 4, 6 and 8 missing.
4. 4.Check the diagonal: 1 present (twice), 5 present, 9 present. All three counts are above zero, so the engine reports 1-5-9 with both names, Determination and Resignation.
5. 5.Check the other seven lines. None is complete: 4-5-6 and 3-6-9 hold one digit each (the 5 and the 9); 1-2-3, 7-8-9, 1-4-7, 2-5-8 and 3-5-7 hold two each.

The Mulank is 7 (2 + 5 = 7) and the Bhagyank is also 7 (2 + 5 + 1 + 1 + 9 + 7 + 0 = 25, then 2 + 5 = 7). Neither number enters the arrow test. On the separate Lo Shu plane check the same date completes the Will plane, 9-5-1, and has the Thought plane, 4-3-8, empty. That overlap is not a coincidence, as the next sections show.

How often birth dates complete it

The engine was run over every calendar date from 1 January 1950 to 31 December 2010, 22,280 dates.

One date in three completes the line, more than any other arrow in that span. The split by century is stark: 7,416 of the 18,262 dates from 1950 to 1999, but only 89 of the 4,018 dates from 2000 to 2010, because a 20xx year gives a 2 and a 0 instead of a 1 and a 9. Every one of the 581 dates with no 1, 5 or 9 at all falls in 2000 or later. The very first date in the span, 1 January 1950, already completes it.

On 4,284 dates it is the only arrow. Its commonest partners are 2-5-8, the Arrow of Emotions (1,146 dates), 1-2-3, the Arrow of the Planner (810), and 7-8-9, the Arrow of Activity (564).

What the books say

Erik Tao, Numerology: Metaphysical Secrets

Tao gives both names and both texts. He also reads lines by how full they are: full for the most dominant traits, two numbers for some of the qualities, one or none for an area needing work, and an empty line for adaptability with no particular trait. The engine reports full lines only.

His first worked example has a small inconsistency worth knowing. The text gives a birthday of 16 February 1889, but the date written for the grid is 02/15/1889, and the grid drawn matches the 15th. From that grid he reads Determination and Emotions as the dominant traits. The engine agrees for 15 February 1889, returning 1-5-9 and 2-5-8; for 16 February 1889 it returns no arrow at all, because swapping the 5 for a 6 breaks both lines.

In his January 1998 example the 1-5-9 line holds only the 1 and the 9, yet he names determination among the most prominent traits, using his two-number reading. The engine returns no arrow for that date. And when he builds a grid from the letters of a name, he finds five full lines and calls 1-5-9 the most dominant of them. This app does not use names for arrows.

Life With Number Magick: the same digits, called Will Power

Rrachita Gupta's Life With Number Magick Part 2 (the numerology masters notes) uses the Lo Shu square, 4-9-2 over 3-5-7 over 8-1-6, where 9, 5 and 1 form the centre column. It calls that column the Will Power arrow, also the "Arrow of Success", describing strong-willed, opinionated people who persist to their goal (pp. 149-151). The lack of all three is its Arrow of Indecision. Its own "Determination" is a different line, 2-5-8. This app's plane check also uses the 9-5-1 column and calls it the Will plane, which is why the worked date above completes both.

Here the books agree on the digits and broadly on the flavour (persistence, ambition) but not on the name, and only Tao attaches a negative reading to the full line. Gupta also claims that nobody has lacked 9-5-1 for a thousand years and that it will reappear this century. The sweep is consistent with the second half: the 581 dates in it with no 1, 5 or 9 all fall from 2000 onwards. It cannot test the first.

Where the corpus is silent

Advanced Vedic Numerology's arrows use its own 3-1-9 / 6-7-5 / 2-8-4 grid, and none of them is 1-5-9; the Vedic grid calculator runs those. No other numerology book in the corpus discusses the Arrows of Pythagoras.

What the arrow cannot tell you

• Which reading applies. The source gives Determination and Resignation to the same full line and no way to choose.
• Much about an individual born in the 1900s. A third of those dates have it, mostly because the year starts with 19.
• Anything from the counts. Two 1s or four 1s give the same result.
• Anything tested. The texts are one author's descriptions; the app makes no prediction from them.

The digits have their own pages: Lo Shu number 1, number 5 and number 9. Its commonest partners are the Arrow of Emotions and the Arrow of the Planner; the other diagonal is the Arrow of Compassion. The grid is defined under Lo Shu grid.

Do I have Determination or Resignation?

The app does not say, because its source does not. Erik Tao names both on the same full 1-5-9 line with no rule for choosing, and the engine returns both.

Why do so many people born in the 1900s have this arrow?

The year 19xx supplies the 1 and the 9, so a single 5 anywhere else completes the line. In the run over 1950 to 1999, 7,416 of 18,262 dates did.

Is this the Will Power arrow I have read about elsewhere?

Same digits, different name and square. Life With Number Magick calls 9-5-1 on the Lo Shu square Will Power; Erik Tao calls 1-5-9 on his layout Determination. This app follows Tao for arrows and calls 9-5-1 the Will plane in its plane check.

My date has a 1 and a 9 but no 5. Does it count?

Not here. The engine reports a line only when all three digits are present. Tao would read a two-number line as a partial trait, but the app does not.