# Chapter 12 — Synthesis: How Proved Truth Compounds

Status: drafting. Claim inventory: see `README.md` ch. 12.

This chapter is the scoreboard. It collects everything the campaign proved, in order of what actually moved performance — and why the Q-campaign's 9 refutations were as informative as its 2 passes.

## The scoreboard (clean lake, exp 21–43)

| Lever | Evidence | Net effect |
|-------|----------|-----------|
| **Data quality** | exp 21 (collapse), 22–24 (fix + revalidation) | The single largest swing: pre-reset +7.77% became −20.6% on the same config, then reappeared as a real signal. Everything before the reset is void. |
| **Cost relief / construction** | exp 26 (n_drop 2→1): −3.21%→+2.13%; exp 39 (weekly, Q07): **+12.51%, IR 1.24, maxDD −4.13%** | The dominant *positive* lever. Same signal, cadence changed. |
| **Feature pruning** | exp 9, 24, 25, 31, 33 (Q01), 43 (Q11) | Generic pruned set > model-specific; one warranted addition (sp_sharpe_22, Q01); standalone reversal refuted (Q11). |
| **Ensemble** | exp 28 (2<5 seeds), exp 34 (Q02: 10 seeds) | Real but bounded: breadth saturates ~5 seeds; extra seeds don't clear costs. |
| **Risk limits** | exp 40 (Q08) | Safety net only: floor binds, no IR edge, DD relief is defunding. |
| **Gates** | exp 20, 42 (Q10) | Refuted: regime overlay churns, adds cost, no edge. |
| **Sizing** | exp 38 (Q06) | Weak: half-Kelly mildly positive, below bar. |
| **Long-short** | exp 41 (Q09) | Refuted by turnover: pre-cost edge +6.6% destroyed by $96.7k cost. |

`PROVEN — EVIDENCE#010–032`.

## What the Q-campaign settled

Eleven pre-registered runs, two passes:

1. **Q01 PASS** — M2's risk-adjusted 22d Sharpe-drift feature reproduces on the compact set (net +6.53%, IR 0.62). Promotes exp-30's lone result from HYPOTHESIS to PROVEN. `EVIDENCE#022`.
2. **Q07 PASS** — weekly recompute is the campaign's best construction (net +12.51%, IR 1.24). The forward path. `EVIDENCE#028`.
3. **Nine refutations** — seed breadth (Q02), wider book (Q03), long labels under daily churn (Q04/Q05), Kelly sizing (Q06), risk-limit-as-alpha (Q08), long-short (Q09), regime gate (Q10), standalone reversal (Q11). Each closed a direction the desk had been considering, at one-run cost each. `EVIDENCE#023–027, 029–032`.

The refuted runs were as valuable as the passes: the label-horizon result (22d label, IC 0.097, yet net negative) is exactly the kind of counterintuitive fact a desk must not re-learn. `REFERENCED (falsification) + PROVEN (recorded negatives)`.

## The order of operations a reader should copy

1. **Fix data first** — re-validate the lake before any run (ch. 06).
2. **Attack turnover before signal** — cadence and dropped-name policy are the proven levers (ch. 09).
3. **Test features one at a time** against the reference (ch. 07); prune, don't add (ch. 04).
4. **Use a small ensemble** (5 seeds) and stop there (ch. 05).
5. **A/B risk limits** before shipping; keep them as a safety net (ch. 10).
6. **Reconcile live** — the funnel and slippage are the only claims that count (ch. 00/11).

## Open questions

- `TODO(evidence-needed: a second live round beyond round 3, to confirm slippage and funnel hold under a different market regime)`
- `TODO(evidence-needed: reconcile realized cost against the 5bp/15bp/$5 backtest model over a full position window)`
- `TODO(evidence-needed: whether sp_sharpe_22 still helps when combined with the weekly-rebalance construction of ch. 08)`

### Settled open questions

- ~~`reproduce exp 39 weekly rebalance on a second window, then a live round`~~ — **ANSWERED (negatively):** Q13 (exp 45) tested weekly on 2025 OOS: net −4.21% IR −0.52. The edge is window-dependent, not robust. `EVIDENCE#037`.
- ~~`long-horizon label at weekly cadence — the proven signal edge with the proven low-turnover construction`~~ — **ANSWERED:** Q12 (exp 44): 22d+weekly net −4.88% IR −0.566. Q21 (exp 51): 10d+weekly net +1.19% IR 0.148. Both below IR 0.5 acceptance. Weekly is a universal cost lever (~10pp improvement) but the5d label remains the sweet spot. `EVIDENCE#036/042`.
- ~~`out-of-universe (non-ETF) validation of the compact stochastic set`~~ — **ANSWERED (negatively):** Q14 (exp 50): RankIC −0.02, ICIR −0.07 on 30 liquid single-stock names. Signal is noise outside the 50-ETF panel. `EVIDENCE#033`.

## Evidence cited in this chapter

Composite of `EVIDENCE#010–032`; see the per-chapter evidence tables (ch. 04–10) and `EVIDENCE.md` for run/branch level citations.