Benchmark Almanac

SSH stress-testing evaluation (Anthropic)

Claude Opus 4.6 95% Only in system cards

Models continue prefilled conversations about suicide and self-harm built from anonymized user feedback. Score is the rate of appropriate course correction.

In-house Anthropic evaluation. The tasks are not public.

Made by Anthropic Released Feb 2026 Wellbeing and sycophancy Tasks kept private Last in a system card Feb 2026 Last model added Feb 2026
Level
Expert Specialists with years of training, often over hours of work
Scored
Graded by a model A language model scores each response, usually against a rubric.
Answers
Open-ended Free-form text, documents, designs or media judged as a whole.
2
Models scored in lab cards
2
System cards report it, from 1 lab

Claude Opus 4.6 leads with 95%

Best score per model as labs report them in their own cards. Labs pick their own settings, so these compare less cleanly than independent runs.

  1. 1 Claude Opus 4.6 95%
  2. 2 Claude Sonnet 4.6 92%
#ModelScoreSettingDateSource
1 Claude Opus 4.6 95% Feb 2026 Model card
2 Claude Sonnet 4.6 92% Feb 2026 Model card

The best score passed 85% in Feb 2026

All the scores we have, one dot each, so a model tested at several settings appears more than once.

Reported by the lab in its model card
0% 20% 40% 60% 80% 100% 2026 Near the ceiling (85%) Claude Opus 4.6 0% 20% 40% 60% 80% 100% 2026 Near the ceiling (85%) Claude Opus 4.6

Labs report it only in system cards

We read the headline results of 479 launch posts from 51 labs, and none of them list this benchmark. Some system cards do, below.

2 system cards report it, from 1 lab

Besides launch posts, we read the system cards, model cards and technical reports labs publish with a release. They report far more, including safety and frontier-risk tests.

DateDocumentScoreAs the document writes itSection
17 Feb 2026 Claude Sonnet 4.6 system card 92 SSH stress-testing evaluation, appropriate response rate, value printed on chart (Figure 3.4.2.B) Safety
5 Feb 2026 Claude Opus 4.6 system card 95 SSH stress-testing evaluation, appropriate course-correction rate on prefilled conversations, value printed on chart (Figure 3.4.2.B) Safety

More in Safety and alignment

All 444 in Safety and alignment
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  • AgentDojo In use Agents do tool-use tasks while tools and data carry prompt injections. Attack success rate counts hijacked runs. Grok 4 Fast 0%
  • MASK In use Measures whether a model contradicts its own elicited beliefs under pressure to lie. Honesty separated from accuracy. Muse Spark Open 98.1%
  • Gray Swan IPI Arena benchmark In use Indirect prompt-injection attacks from public red-teaming competitions replayed on tool, coding and browser agents. Attack success rate at k attempts. GPT-6 Astra 8.50%
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