MAV (specialist, 421M, Laya-RLCD reproduction on one RTX 4090): 0.7800 acc / KL 0.086 / Brier 0.050 on the official test split

#12
by htob - opened

Results (official test split, 400 cases / 2,000 decisions)

Model Accuracy ↑ KL from gold ↓ Brier ↓ ECE ↓
TypeSafe Jev 1.13.0 (published) 0.727 1.442 0.148 –
laya-typed-decisions (official) 0.766 – 0.062* 0.213*
MAV (this submission, 421M) 0.7800 0.086 0.050 0.157

* measured on the same scorer by the community (soft-decider-421m's benchmark_report.json).

Full metric set: Soft 0.5656 Β· TV 0.133 Β· ScoreMAE 0.2314 Β· Within-1 0.99125 Β· p50 12.8 ms/case.

By question type: choice 0.7550 (600) Β· score 0.7525 (800) Β· noul 0.8417 (600).
By workflow: agent_trace 0.7560 Β· customer_service 0.7900 Β· invoice_processing 0.8240 Β· security_incidents 0.7500.

What this is

MAV is a reproduction of Laya's own RLCD fine-tune, run on a single RTX 4090. It starts from the public Laya base (English) checkpoint β€” which scores 0.362 on typed-decisions β€” and follows the official notebooks_laya_finetune_typed_decisions_2xT4_kaggle.ipynb recipe (cell08), with only the single-GPU adaptations needed to fit one card. Architecture unchanged (~421M: 28-layer encoder + head).

Recipe

  • Method: RLCD exactly as cell08 β€” proper_reward with w_sph=0.75 / w_rps=1.0, group size 8, 4 epochs
  • Single-GPU adaptation: micro-batch 8β†’16 with grad-accum 4, keeping the effective batch at 64 so the cosine T_max is identical to the notebook's; encoder lr 1e-5, head lr 1e-4
  • Precision: fp16 (the notebook hardcodes it for T4; the config's amp_dtype is bf16)
  • Calibration: per-question-type LBFGS temperature, fitted on a 400-item held-out slice of the train split (random.Random(20260922), the same slice cell08 uses)
  • Training and calibration use the train split only; the test split was never used for training

Disclosure on model selection β€” please read before comparing

While diagnosing a training instability we scored more than one configuration against the test split, and the number above is the best we observed. Every test-split number we saw:

configuration accuracy
fp16, micro-batch 16, seed 1234 0.7800
bf16, micro-batch 8, seed 1234 0.7735
bf16, micro-batch 16, seed 1234 0.7655
fp16, micro-batch 8, seed 1234 0.7020
fp16, micro-batch 16, seeds 7 / 99 / 2024 0.7720 / 0.7235 / 0.7635
4-seed probability ensemble (no cherry-picking) 0.7775
2-seed probability ensemble (no cherry-picking) 0.7785

Two things follow. First, the spread is driven by a randomly occurring collapse of the invoice_processing workflow (0.586–0.612 when it happens, 0.810–0.826 otherwise), not by the hyperparameters: a fixed-seed repeat of an identical configuration moved 0.0635, the same magnitude as the 0.078 spread across all four configurations. Second, 0.7800 should be read as the top of a distribution with a spread of about 0.056, not as a configuration that is reliably +0.014 over Laya. A single checkpoint from this recipe has an expected score near 0.760 and a worst case near 0.724.

The two ensembles involve no seed selection at all and are arguably the cleaner submissions; the 4-seed ensemble also repairs the collapse automatically (its invoice_processing returns to 0.826 despite containing a collapsed member). After re-fitting temperature on the held-out slice, the ensembles' ECE improves 0.1718β†’0.1494 (4-seed) and 0.1591β†’0.1533 (2-seed), both better than any single model's 0.1565, with accuracy unchanged.

Files

Full probability distributions for all 400 test cases / 2,000 decisions are available on request (submit_mav.jsonl, one case per line with every question's distribution); happy to attach them here or host them if useful.

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