refract-hsmall-blend2 — divergent decision refraction (shipped model)

LoRA adapters that teach ibm-granite/granite-4.0-h-small (32B total / ~9B active, hybrid Mamba+MoE) to refract a hard decision into four genuinely distinct, viable strategic threads — each a different kind of move (confront, evade, co-opt, transform, delegate, endure) — and refuse to blend them into one hedged answer.

This is the shipped result of a concluded 8-round research program. The full record — every round, every number, every mistake, and the negative results — is in the project's working paper: github.com/Nikhiljangra07/divergence-formula.

What's in this repo

Path	Role
dec_blend2/	Decomposer adapter — problem → 4 distinct strategic angles
wrk_blend2/	Worker adapter — one angle → a concrete, viable thread with projected consequences
eval/	Raw eval outputs (DAV harness JSON + per-thread JSONL, held-out + benchmark sets)

Both adapters: LoRA r=64 / α=64, all-linear targets, SFT on 6,745 judge-gated synthetic rows (1,349 decomposer / 5,396 worker), including a targeted "viable-cunning" influence round.

Headline result

Single-session blind judging (Gemini 2.5 Pro, temp 0), 48 out-of-distribution modern decision problems, Claude Haiku 4.5 generated fresh in the same session as the frontier competitor:

model	overall	viability	distinctness	decisiveness	foresight
this model (BLEND2)	4.55	3.56	4.90	4.83	4.21
Claude Haiku 4.5	4.72	4.25	4.75	4.83	4.52

It beats Haiku 4.5 on the objective it was built for — distinctness (4.90 vs 4.75) — and ties it on decisiveness, with ~9B active parameters. It loses overall (−0.17); the residue is viability and foresight, and the working paper says so plainly.

Note on the two eval harnesses: the table above is the same-session comparative re-judge (working paper §14–15). The JSON files in eval/ are from the project's internal DAV harness (a stricter per-dimension rubric on the same problem sets) — different scale, same model. Both are documented in the working paper; nothing here is cherry-picked across harnesses.

Usage

from transformers import AutoModelForCausalLM, AutoTokenizer
from peft import PeftModel

base = "ibm-granite/granite-4.0-h-small"
tok = AutoTokenizer.from_pretrained(base)
model = AutoModelForCausalLM.from_pretrained(base, torch_dtype="bfloat16", device_map="auto")

# Stage 1: decompose the problem into 4 distinct angles
dec = PeftModel.from_pretrained(model, "Nikhil0097/refract-hsmall-blend2", subfolder="dec_blend2")
# ... generate angles, then per-angle:
# Stage 2: swap to the worker adapter and expand each angle into a full thread

The exact two-stage prompts and generation settings are in the GitHub repo (round2_kit/dav_eval_v5.py). The base model needs the Mamba kernels; the training/inference engineering traps are documented in the working paper §13.

Honest scope

• Specialist scoreboard, not a general benchmark win: the rubric measures the one operation the model was trained for.
• Known weaknesses: viability (3.56 vs Haiku's 4.25) and foresight (4.21 vs 4.52).
• Levers identified but not run (program concluded): hard-negative DPO at 9B-active scale, inference-time viability checking, a foresight-targeted corpus.
• Training data is fully synthetic (DeepSeek V4 generator + LLM judge gate); no human-authored or user data.

Provenance & findings

The program's five load-bearing findings (teachability, quality-beats-size, 3.4B capacity entanglement, entanglement breaking at ~9B active, cheap-generator saturation) are in the working paper. Total program cost: ~$175. Built solo by Nikhil Jangra.