docs/research/2026-07-23-small-model-sota-theory.md

Defining SOTA in a restricted space — the math, what's validated, what isn't

Date: 2026-07-23 · Prompted by the operator's challenge: "you need to answer real basic HumanEval and SWE benchmarks with a small model — how do you plan to define SOTA in such a restricted space other than saying it can be honest? Have you actually done any math or validations?" This document is the answer, written for human evaluators. Every number carries its source; every formula states what has and has not been checked against reality.


1. The claim we refuse to make, and the claim we make instead

Refused: "our ≤8GB system will top HumanEval/SWE-bench leaderboards." Unwinnable and already conceded in SIGMA0-OURO-CODER §2: open 32B-class models match closed frontier on SWE-bench; parameters are not our axis.

Made (falsifiable, Pareto form): on the operating point ⟨local ≤8GB, verified answers, deterministic serving, bounded cost⟩, the system achieves a cost–reliability frontier no published system matches at equal local budget: specifically, (a) higher verified pass@1 than any single ≤8GB model call at ≤K× its cost, and (b) a precision-of-claimed-solve near 1.0 (when it says "solved," tests pass) that leaderboard systems do not report at all. SOTA-in-restriction = best measured point on that frontier, registered in BENCHMARKS.md against published baselines — not a vibe about honesty.

The product form of the claim: for a user with an 8GB box, no other system delivers more verified correct answers per dollar per day. That is a measurable sentence.

1.5 The size envelope (operator constraint, 2026-07-23 — supersedes any 7B-as-cheap-tier framing)

The focus tier must run on CPUs, small GPUs, and less-optimized PCs. 7B-class models crash the reference workstation — they are too large to BE the product tier. Therefore:

  • Product/cheap tier: ≤3B-class, ≤4GB footprint, CPU-viable (Qwen2.5-1.5B/3B-class today).

The probe ladder makes this workable, not just tolerable: at 1.5B the internal truth signal already clears the verifier gate (0.980 factual / 0.774 assoc de-glossed AUROC, measured) — the CPU-viable tier has a usable calibration signal. At 0.5B it does not (0.703 assoc).

  • 7B+ is escalation-tier only — cloud or capable boxes, never assumed on the user's machine.

The measured 0.829 HumanEval (7B Q4) is re-scoped from "our baseline" to escalation-tier reference; the product baseline to measure is the 1.5B/3B tier's own number.

  • The ternary artifact (ADR-0026) is the capability path, not an optimization: W1.58A8 puts a

7B-class parameter count in ~2GB with CPU-native kernels (BitDistill: 2.65× faster CPU) — the only route to "7B-class capability on the computer you already own." Probe survival at ternary (#2873) is accordingly promoted from acceptance-test to critical-path.

  • Consequence for the math: with a smaller p (1.5B-class solve rate), §2.1's verifier

amplification is not an enhancement — it is the mechanism. The product is N cheap CPU samples

  • a real verifier, not one big model call.

2. The math (each formula: status, then the numbers we actually have)

2.1 Verifier amplification — why a small model can reach large-model pass@1 on verifiable work

For a task with executable tests, sample N candidates from the cheap model (per-candidate solve probability p), keep the first that passes the visible tests:

P(verified solve) = τ · (1 − (1−p)^N) + (1−τ) · FA(N) cost ≈ N·c₀ + c_exec

where τ = probability the visible tests catch a wrong program (test adequacy), and FA(N) the false-accept from weak tests. Status: the (1−(1−p)^N) core is standard pass@k mathematics (Chen et al. 2021) — imported, not ours; the system contribution is running it with a real exec-verifier and a deterministic outer loop. Validated in-repo: 7B Q4_K_M measured 0.829 single-shot HumanEval-164 on-box (quant-cliff run); the exec-verified coding-golden gate measured 0.96 pass@1 (#2173). Predicted by the formula: p=0.55 (0.5B tier), N=8, τ≈0.9 → ~0.89 verified at ~8×cheap-cost ≈ still ≥5× cheaper than one 7B call by the measured cost ratio. NOT yet validated: the full HumanEval-164 cascade number (the missing run, now queued — §4). τ on HumanEval visible tests is unmeasured in-repo; literature puts hidden-test false-accepts at 5–15%, so FA is a real term, not a footnote.

2.2 Cascade economics — the cost side of the frontier

With cheap-tier sufficiency σ (verifier-confirmed solves) and escalation rate e = 1−σ to a tier costing c₁:

E[cost] = c₀ + e·c₁ E[accuracy] = σ + e·ρ (ρ = escalation rescue rate)

**Status: elementary decision-theoretic cascade (FrugalGPT lineage — imported); our contribution is instrumenting it with a ground-truth verifier so σ is confirmed, not self-assessed. Validated in-repo (live, #2798/#2800 + ADR-0030 Phase-0): strong cheap tier ran e≈0 at 8.3× cheaper; weak-tier + rescue measured 88.4% > 84.8% (rescue is real); fully-local 0.5B→7B cascade solved 18/18 MBPP-basic at e=6%**; honest-unsolved reporting observed (the rle task) rather than a fabricated pass.

2.3 Abstention as expected-utility optimum — why honesty is a scoring advantage, not a virtue

Under any deployment where a wrong assertion costs λ (review time, broken CI) and a correct one pays +1:

E[U] = P(assert ∧ correct) − λ·P(assert ∧ wrong) ⇒ assert iff P(correct) > λ/(1+λ)

A calibrated confidence signal makes the threshold implementable; an uncalibrated one makes it noise. **Status: proper-scoring folklore (Kalai lineage) — imported. Our addition is the signal: the white-box probe. Validated in-repo: probe AUROC on de-glossed truth 0.837 → 0.980 → 1.000 (factual) and 0.703 → 0.774 → 0.924** (associated-misconception hard case) across 0.5B/1.5B/7B(4-bit) — measured on our hardware, replicating [2606.02628] and bounding [2510.09033]'s pessimism as scale-dependent. M1's ledger invariant replayed clean (0 free rises /pairs). NOT yet validated: the probe threshold used live as the assert/abstain gate on a benchmark (that composition is exactly issue #2858's experiment); probe survival at 1.58-bit (#2873).

2.4 SWE-bench honestly — where we actually are

Measured truth: 0/5 agentic (autowork), 0/3 single-shot Qwen. No math above turns ainto a leaderboard number, and we will not pretend otherwise. What the math does predict: SWE tasks decompose into steps with executable checks (repro script → failing test → patch → suite), which is the cascade's native shape; and under §2.3 any system that submits fewer wrong patches at equal solves dominates on reviewer-cost-weighted scoring. The claim for SWE is therefore staged: first a non-zero verified resolve% with measured abstention precision (target: SWE-bench Lite 25-task slice), then frontier-of-cost comparisons — never raw-leaderboard talk before a number exists.

3. Validated vs. predicted — the one table evaluators should hold us to

Quantity Formula/claim Status Number (source)
7B Q4 HumanEval-164 single-shot baseline MEASURED 0.829 (on-box quant run)
exec-gated coding-golden pass@1 verifier works MEASURED 0.96 (#2173)
cheap-tier sufficiency (easy set) σ MEASURED 18/18 @ e=6% (Phase-0 live)
cascade cost advantage c₀+e·c₁ MEASURED 8.3× cheaper, e≈0 (#2800)
rescue value ρ>0 MEASURED 88.4% > 84.8% (offline)
probe truth-decoding (7B, 4-bit) calibrated signal exists MEASURED 1.000 factual / 0.924 assoc
M1 no-free-confidence on ledger invariant holds MEASURED 0 free rises /pairs
VTD self-improvement crossover to net lift MEASURED-NEGATIVE so far −6 → ±0 (dose-response)
HumanEval-164 full-cascade verified pass@1 §2.1 composition PREDICTED ~0.88–0.92 not yet run (queued)
SWE-bench Lite resolve% staged claim MEASURED 0 — honest floor harness ready, run queued
live probe-gated abstention on a benchmark §2.3 threshold NOT VALIDATED #2858 experiment

4. The falsification plan (what turns claims into numbers)

All heavy runs on the mookman lane / cloud L4 (this workstation is disqualified for training — operator decision 2026-07-23, #2850):

  1. HumanEval-164 cascade run at the SIZE ENVELOPE — cheap tier = 1.5B/3B-class (CPU-viable),

escalation = cloud-only; report ⟨verified pass@1, cost/task, e, precision-of-claimed-solve, CPU tokens/s⟩ vs (a) the tier's own single-shot baseline (to be measured first), (b) the 7B escalation reference 0.829, (c) published numbers. Register in BENCHMARKS.md. The §2.1 prediction (N-sample exec-filtered ≥0.85 at the small tier) is falsifiable by this run.

  1. SWE-bench Lite 25-slice — resolve% + abstention precision, both reported; success = any

verified non-zero with precision ≥0.9, else the honest null stands.

  1. Probe-gated live abstention (#2858) — does gating by the probe raise utility at λ∈{1,3}?
  2. V1 honest-teacher verdict (#2850, handed off) and V2 dose-response (#2847).

5. Stated plainly for human evaluators

We have not demonstrated SOTA on HumanEval or SWE-bench, and at raw leaderboard terms with a small model we never will — that is a constraint of physics and parameter count, stated up front. What exists today: a measured 0.829 HumanEval baseline on an 8GB box; a live verified cascade measured 8.3× cheaper with real rescue value; a truth-decoding internal signal measured at 0.92–1.00 AUROC at the 7B tier; and composition math — none of it novel, all of it standard pass@k/cascade/proper-scoring theory — predicting ~0.9 verified HumanEval at a fraction of single-model cost. The prediction is falsifiable by one queued run. Honesty enters not as the product's slogan but as the scoring theorem (§2.3): under any accounting where wrong answers cost something, calibrated abstention strictly dominates — and we measured the calibration signal. Judge us on the table in §3 and on whether the queued runs land where the math says.