Appears as centre
Yes
Share of birth dates
9.08%
Dates producing it
3,316 of 36,525
Arcana 18 is even, so it can occupy the centre of a
matrix — and does, for roughly 9.08% of birth dates.
The eleven even arcana split the centre position almost equally between them.
That is not a quirk of our calculator. It follows from the formula, and it
means half the deck is structurally excluded from the most important position
in the chart.
Why only even arcana reach the centre
The centre is defined as A + B + C + D, where D is itself A + B + C. Substitute
it in and the centre is 2 × (A + B + C) — an even number before
any reduction. Reduction subtracts 22, which is also even, so the result stays even
however many times it is applied.
Running all 36,525 real calendar dates from 1930 to 2029 confirms it: the eleven
odd arcana appear in the centre exactly zero times, and the eleven even arcana
divide the position between them at about 9.1% each.
Worth knowing before paying for a reading built around your central arcana. The
system is presented as deeply personal, and in this respect it is considerably
more constrained than it looks — a fact you will not find on the sites selling it.