The Drip Lines — where the table ends, and the anomaly the ledger cannot see

The nuclear chart has an edge: add neutrons to any element and eventually the next one simply does not stick — the drip line. Its most celebrated feature is the oxygen anomaly: oxygen's drip line stops abruptly at O-24, while adding a single proton extends it by six neutrons — fluorine runs all the way to F-31. Explaining that jump took three-nucleon forces (Otsuka et al., PRL 105, 032501 (2010)), one of the landmark results of modern nuclear theory, credited here and untouched. The 80/20 list proposes "geometric drip lines." The ledger can be asked today, so it was asked today — with the P51/P55 caution stamped in advance: drip lines turn on separation energies of a few hundred keV to a few MeV, exactly the difference-of-masses regime where the ledger's smooth surface has already failed twice. Result: the smooth surface lands the right neighbourhood — mean miss 3.4 neutrons over = 6–12 — and completely fails the oxygen–fluorine jump, as it must. Both halves are reported at full size. [computed for the neighbourhood; null-fail on the anomaly] This record holds one paper on its own and is refreshed every couple of months. The complete deposit, 10.5281/zenodo.21788037, holds every paper with its code and data and is updated first; for the newest version of this paper, go there.