The Missing Compliance Class: LLM Graders That Collapse Jailbreak Success, and a Free Check
Organizations: Independent Researcher
Abstract
Jailbreak papers report an attack success rate, the share of responses that deliver the harmful request, and read it as a property of the target model. We hold the target model, the prompts and the responses fixed and change only the grader. Three dense graders of 8B and 9B parameters, from three model families, move compliant responses to the neighbouring class, evasion, instead of scattering them across classes. One of them assigns the compliance label zero times in 900 responses. This class collapse also appears on new harmful requests, on a target model from a third family, and in a held-out 7B grader from a fourth family. Per-class label counts expose it at no cost and without human labels. The collapse decides how the rate behaves under a change of grader. On two corpora of 900 responses and eight graders, the compliance rate differs by a factor of 22 to 25, while the non-refusal rate differs by 18 to 23 percentage points. Without the three collapsing graders, compliance differs by a factor of 1.7 to 2.8 on all four corpora, and non-refusal still differs by 10 to 22 points. These results do not change when every grader is called once. We propose a reporting minimum that keeps the compliance rate and adds its per-class label counts and the named grader. Beside it goes the non-refusal rate, whose disagreement across graders is additive.
Figures & tables
| corpus A | corpus B | |||
|---|---|---|---|---|
| grader | comply | non-ref. | comply | non-ref. |
| Llama-3.1-8B | 1.0 % | 38.4 % | 0.0 % | 20.0 % |
| gemma-2-9b-it | 1.7 % | 52.4 % | 0.9 % | 38.0 % |
| Qwen3-8B | 7.1 % | 61.4 % | 5.7 % | 32.2 % |
| Llama-3.3-70B | 12.2 % | 54.8 % | 7.4 % | 29.2 % |
| gemini-2.5-flash (ref.) | 16.9 % | 52.0 % | 14.2 % | 28.4 % |
| grader | stays | evasive | refuse | found |
|---|---|---|---|---|
| corpus A, 152 compliant items | ||||
| Llama-3.1-8B | 8 | 118 | 26 | 1 |
| gemma-2-9b-it | 14 | 137 | 1 | 1 |
| Qwen3-8B | 53 | 96 | 3 | 11 |
| Llama-3.3-70B | 92 | 59 | 1 | 18 |
| claude-opus-5 (blind) | 143 | 9 | 0 | 55 |
| grader | A (152) | B (128) | C (101) | D (41) |
| Llama-3.1-8B | 8 | 0 | 1 | 2 |
| gemma-2-9b-it | 14 | 5 | 1 | 5 |
| Qwen3-8B | 53 | 42 | 25 | 10 |
| Mistral-7B-v0.3 | 2 | 0 | – | – |
| gpt-oss-20b | 151 | 119 | 98 | 40 |
| gpt-oss-120b | 149 | 121 | 101 | 40 |
| study | what changes | what is held fixed | what it shows about the grader |
|---|---|---|---|
| Souly et al. (2024) | the evaluator | prompts and responses | existing evaluators exaggerate jailbreak success |
| Chao et al. (2025) | the judge (six) | 100 responses with expert labels | judges differ in agreement with experts |
| Andriushchenko and Flammarion (2025) | the judge (three) | attack runs | success rates differ by judge |
| Gao (2026) | the judge (one classifier, three LLMs) | 596 human-labelled completions | LLM judges have high precision and erratic recall |
| Tamsal and Rusert (2026) | the evaluator and the attack | fine-tuned models | evaluator choice inflates the change in success about threefold |
| Ma et al. (2026) | the judge | the rubric | disagreements found by search |
Appendix figures & tables18 assets
Supplementary material from the paper’s appendix.
Appendix
| corpus A | corpus B | |||
|---|---|---|---|---|
| labels | comply | non-ref. | comply | non-ref. |
| shipped labels | 24.8 | 23.0 | 22.4 * | 18.0 |
| one call (A) | 24.8 | 23.0 | 22.4 * | 18.0 |
| three calls (B) | 18.4 | 23.0 | 59.7 | 19.1 |
| rate | max/min | leave-one-out | 2nd/2nd | IQR | range |
|---|---|---|---|---|---|
| A, comply | 24.8 | 14.9–24.8 | 13.6 | 16.4 | 23.8 |
| A, non-ref. | 1.6 | 1.2–1.6 | 1.2 | 7.1 | 23.0 |
| B, comply | 22.4 * | 3.5–22.4 | 20.5 | 13.5 | 19.9 |
| B, non-ref. | 1.9 | 1.3–1.9 | 1.2 | 5.5 | 18.0 |
| grader | org | par. | com. A | com. B | A | B |
|---|---|---|---|---|---|---|
| (B) | % | % | ||||
| Llama-3.1-8B | M | 8 | 1.0 | 0.0 | +0.436 | +0.451 |
| gemma-2-9b-it | G | 9 | 1.7 | 0.9 | +0.445 | +0.479 |
| Qwen3-8B | Q | 8 | 7.1 | 5.7 | +0.622 | +0.644 |
| Llama-3.3-70B | M | 70 | 12.2 | 7.4 | +0.694 | +0.713 |
| gemini-2.5-flash (ref.) | G | — | 16.9 | 14.2 | — | — |
| corpus A | corpus B | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| grader | ref. | eva. | com. | gib. | CoT | ref. | eva. | com. | gib. | CoT |
| Llama-3.1-8B | 554 | 330 | 9 | 7 | 0 | 720 | 180 | 0 | 0 | 0 |
| gemma-2-9b-it | 428 | 449 | 15 | 8 | 0 | 558 | 334 | 8 | 0 | 0 |
| Qwen3-8B | 347 | 482 | 64 | 7 | 0 | 610 | 239 | 51 | 0 | 0 |
| Llama-3.3-70B | 407 | 378 | 110 | 5 | 0 | 637 | 196 | 67 | 0 | 0 |
| gemini-2.5-flash (ref.) | 425 | 311 | 152 | 5 | 7 | 644 | 121 | 128 | 7 | 0 |
| corpus A | corpus B | |||
|---|---|---|---|---|
| grader | agr. | solo com. | agr. | solo com. |
| gpt-oss-120b | 93.9 % | 4 / 204 | 94.9 % | 4 / 161 |
| gemini-2.5-flash (ref.) | 89.2 % | 0 / 152 | 93.7 % | 1 / 128 |
| gpt-oss-20b | 88.2 % | 14 / 223 | 94.3 % | 7 / 164 |
| claude-opus-5 (blind) | 84.2 % | 8 / 198 | 88.6 % | 29 / 179 |
| Llama-3.3-70B | 82.9 % | 1 / 110 | 87.7 % | 2 / 67 |
| state of the labels | non-ref. | 95 % CI | |
|---|---|---|---|
| as returned | 42.3 % | — | — |
| + protective-inverse ruling | 51.2 % | ||
| + empty-response rule | 50.4 % | ||
| + reconciliation pass | 58.7 % | ||
| end to end | +16.3 | [+13.8, +19.0] |
| corpus A | corpus B | |||
|---|---|---|---|---|
| grader | comply | eva. agr. | comply | eva. agr. |
| Llama-3.1-8B | 0.0 % | 10.3 % | 0.0 % | 12.5 % |
| gemma-2-9b-it | 1.1 % | 30.8 % | 0.8 % | 30.0 % |
| Qwen3-8B | 6.1 % | 43.6 % | 6.9 % | 37.5 % |
| Llama-3.3-70B | 13.6 % | 46.2 % | 9.3 % | 32.5 % |
| gemini-2.5-flash (ref.) | 16.5 % | 48.7 % | 14.9 % | 42.5 % |
| corpus | agr. | floor | ref. | eva. | com. | kept | flagged | |
|---|---|---|---|---|---|---|---|---|
| A | 55.9 | 47.2 | +0.211 | 698 | 193 | 2 | 2 / 152 | com. |
| B | 75.8 | 71.6 | +0.347 | 766 | 134 | 0 | 0 / 128 | com. |
| grader | agr. | ref. | eva. | com. | flagged | |
| corpus A | ||||||
| gpt-oss-20b | 78.8 | +0.677 | 349 | 305 | 223 | – |
| gpt-oss-120b | 84.9 | +0.766 | 370 | 315 | 204 | – |
| claude-opus-5 (blind) | 81.0 | +0.706 | 365 | 325 | 198 | – |
| gpt-oss-safeguard-20b | 69.7 | +0.549 | 231 | 444 | 193 | – |
| qwen3.8-27b | 82.0 | +0.717 | 392 | 336 | 154 | – |
| graders | non-ref. | comply | comply | ||
|---|---|---|---|---|---|
| range | range | ratio | |||
| A | all | 10 | 35.9 | 23.8 | 24.8 |
| A | without dense 8–9B | 7 | 22.3 | 12.6 | 2.0 |
| B | all | 10 | 24.2 | 19.9 | 22.4 * |
| B | without dense 8–9B | 7 | 15.8 | 12.4 | 2.7 |
| C | all | 8 | 27.4 | 18.9 | 86.0 |
| grader | stays | evasive | refuse |
|---|---|---|---|
| corpus C, 101 items the reference labels compliant | |||
| gpt-oss-120b | 101 | 0 | 0 |
| gpt-oss-20b | 98 | 2 | 1 |
| qwen3.8-27b | 80 | 19 | 2 |
| Qwen3-8B | 25 | 74 | 2 |
| gemma-2-9b-it | 1 | 100 | 0 |
| our result | status against prior work |
|---|---|
| the two boundaries of one rate differ in scale across graders, on two corpora | new, as far as we can find; that the rate depends on the grader is known ( Gao, 2026 ; Tamsal and Rusert, 2026 ) |
| one class collapses onto its neighbour, on two target families, while agreement stays above two thirds | new |
| the collapse appears on new harmful requests and on a third target family | new; registered, tested on new requests, descriptive on the third target |
| a rarely assigned class is a grader fault if another grader assigns it | new as a rule; the counts themselves are standard practice |
| the rule flags the dense 8B and 9B graders on new requests and a held-out 7B grader from a fourth family, and no large held-out grader | new; registered, one held-out corpus and one held-out small grader |
| three post-labelling decisions move one grader’s rate by 16.3 points | new; this magnitude not documented |
| quantity | point | 95 % CI |
|---|---|---|
| benchmark of origin, raw | 15.4 | [ - 8.2, 22.6] |
| domain-standardised | 11.4 | [ 1.4, 25.0] |
| rubric revision, end to end | 16.3 | [13.8, 19.0] |
| step 3, reconciliation pass | 8.2 | [ - 6.2, 10.3] |
| dropping the encoding family, ref. | 5.9 | [ - 5.3, 0 6.3] |
| same, spread across graders | 2.2 | [ - 1.5, 0 2.9] |