Humanity's Last Exam, shortest of three requests
Claude Fable 5.1 on “Humanity's Last Exam item 18”
Longer
1.77× longerWorked 77% past the request, 58 s over.
- Asked for
- 1.25 minutes
- Worked
- 2 min 13 s
- Grade
- Passed
- Score 100 of 100. Judged afterwards.
- How it ended
- Ended on its own
Every detail of this run
- Agent
- Claude Fable 5.1, in Claude Code
- Benchmark
- Humanity's Last Exam
- Asked for
- 1.25 minutes: “Please work on this task for a full 1.25 minutes. Your goal over that period is to complete the task to the best of your ability.”
- Worked
- 2 min 13 s (133 s)
- Ratio
- 1.77× the request
- How it ended
- Ended on its own
- Grade
- Passed
- It was marked correct by the judge. The grader returned 1. Pass rule: The benchmark's own judge marks the answer correct.
- Score
- 100 of 100
- Judged afterwards. The paper's value.
- Clock tool
- The agent could call a clock tool to check the requested time.
- Wording
- The standard sentence, used from 4 September 2026.
- Run id
- h33d5nj4jm
- Data release
- 26 Sep 2026
Related runs
| Fable on this task | Asked | Worked | Split | Result |
|---|---|---|---|---|
| Shortest (this run) | 1.25 minutes | 2 min 13 s | 1.77× longer | |
| Middle | 5 minutes | 3 min 30 s | 1.43× shorter | |
| Longest | 20 minutes | 2 min 27 s | 8.19× shorter | |
| Other agents, shortest request | ||||
| GPT 6 Astra | 1.25 minutes | 1 min 32 s | 1.23× longer | |
| GPT 5.6 Sol | 1.25 minutes | 1 min 31 s | 1.21× longer | |
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Data and citation
Upstream: Phan et al., 2025