Tier Ladder
===========

The TrueWriterScore tier ladder assigns every editor to one of four tiers
based on the hierarchical gate outcomes (v3.2, pre-registered 2026-05-26).

.. list-table::
   :header-rows: 1
   :widths: 20 15 15 10 30

   * - Tier
     - G1
     - Qualifying
     - Cell-Based
     - Description
   * - TRUE_WRITER
     - PASS
     - 4/4
     - Yes
     - Confirmed Molecular Pen candidate
   * - PROBABLE_WRITER
     - PASS
     - 4/4 or 3/4 + cell_based
     - No / Yes
     - Strong evidence, missing cell validation or one gate
   * - EMERGING_WRITER
     - PASS
     - 1–2 / 4
     - Any
     - Partial evidence; further testing needed
   * - NOT_WRITER
     - FAIL or PASS + 0 qualifying
     - —
     - —
     - DSB-maker or insufficient evidence

Pre-registered outcomes (2026-05-26)
--------------------------------------

* **P1 PASS:** ISCro4 is the sole TRUE_WRITER among natural editors
* **P2 PASS:** Zero pen-assemble designs are TRUE_WRITER

Universe composition (Step 5)
-------------------------------

* 29 natural editors (all pen-score entries after S_Mature clamp fix)
* 1,029 computational designs (pen-assemble v0.5.2 catalog)
* **Total:** 1,058 entities

Scorecard summary
-----------------

.. list-table::
   :header-rows: 1

   * - Tier
     - Count
   * - TRUE_WRITER
     - 1
   * - PROBABLE_WRITER
     - 4
   * - EMERGING_WRITER
     - 1,037
   * - NOT_WRITER
     - 16