# Number rules drop by drop (2026-09-24)

Each drop was tested against its own counter: the piece number in the skull drop, the 6-bit binary position (0–63) in the robo drop, the octal position (0–15) in the spooky drop, the printed number in Solstice, n/144 in the Ghost drop, and n/512 in the Review drop. Three kinds of rule were tested against every trait and every tag on the site: Pindar's number classes (Fibonacci, prime, square, odd, even, plus powers of two, palindromes and multiples), regular rhythms (every k-th piece), and mirror or opposite pairings. Only patterns with odds below about one in ten thousand were kept.

## Skull drop: looks follow Pindar's number classes
Pindar's journal gives each number class a look. The sheet follows it.
- **Odd numbers that are not Fibonacci, prime or square are Flaming.** 26 of 26, no exception (journal p006: odd skulls are "on fire, literally").
- **Squares are Silver or Smoke.** 9 of the 10 squares that are not also Fibonacci (journal p005: squares are "smoke wafting between dimensions"). Break: #16 Primordial Ghost.
- **Silver and Smoke never appear on odd or even non-class numbers.** The four off-square cases sit on primes (#31, #41) or Fibonacci numbers (#55, #89).
- **Fibonacci numbers have 5 Dimensions.** 9 of 10. Break: #8 Flaming blobGAN has 2. Only one non-Fibonacci skull has 5: #7, its neighbour. Swapping the Dimensions of #7 and #8 would make the rule perfect.
- **Primes glitch.** This is the known prime rule. The Type word is not the rule: 7 prime skulls carry another Type and still glitch.

## Robo drop: laid out by binary number rules
- **Palindromes are the nagaGANs.** 8 of 8.
- **Primes that are not Fibonacci are Type Glitch.** 14 of 14.
- **Squares from 4 up are Smoke.** 5 of 6. Break: position 16, #145 S1-b0rg, is Silver. The collector says it looks flaming, and it is paired with #150.
- **Every fifth position from 4 is a Cyber cryptoGAN.** 12 of 12 (positions 4, 9 … 59). Only #165 and #185 are Cyber cryptoGANs off this rhythm. This rhythm is why pieces with opposite binary numbers often share a species. The white overlay that takes the GAN's colour occurs only on this rhythm.
- **Numbers with a single 1 in binary are all special.** #130 qubitGAN (000001), #133 (000100) and #161 (100000) have the colour flash. #131 (000010), #137 (001000) and #145 (010000) are the drop's only cyberGANs, with Eyes 0 and eyes drawn as binary digits. #137 at position 8 has essence 'eight'.
- **The Eyes trait only ever says 0, 2, 4 or 8.** No test found it to be an index: no trait, tag, bit or position class predicts it (113 tests, nothing beyond chance).
- **Dimensions 8** occurs on four robos only, #129, #130, #141 and #161, all in the still-eyes class.

## Spooky, Solstice, Ghost and Review drops
No number-class, rhythm or mirror rule was found. The spooky drop has only 16 pieces, too few to test well. Solstice is laid out by its calendar, and the Review drop by its reprise groups; both are already recorded. In the Ghost drop, the only number link is a boilerplate defect in the chain description on #301–#306 and #400 (100/144).

## The breaks
Ten pieces break a number-class look rule: #7, #8, #16, #31, #41, #55, #89 (skull) and #145, #165, #185 (robo). Tag: "Breaks a number-class look rule". Run as hyp90 (card 239): no match.