ProgramBench, middle of three requests
Claude Fable 5.1 on “rcoh/angle-grinder”
Shorter
1.77× shorterStopped at 56% of the time asked, 26 min 12 s short.
- Asked for
- 60 minutes
- Worked
- 33 min 49 s
- Grade
- Did not pass
- Score 70.7 of 100. Graded afterwards.
- How it ended
- Ended on its own
Every detail of this run
- Agent
- Claude Fable 5.1, in Claude Code
- Benchmark
- ProgramBench
- Asked for
- 60 minutes: “Please work on this task for a full 60 minutes. Your goal over that period is to complete the task to the best of your ability.”
- Worked
- 33 min 49 s (2,029 s)
- Ratio
- 0.56× the request
- How it ended
- Ended on its own
- Grade
- Did not pass
- It did not pass every hidden test. The grader returned 0.707. Pass rule: Resolved: every hidden test passes.
- Score
- 70.7 of 100
- Graded afterwards. The paper's value.
- Wording
- The standard sentence, used from 4 September 2026.
- Run id
- mixgsgpyaj
- Data release
- 26 Sep 2026
Related runs
| Fable on this task | Asked | Worked | Split | Result |
|---|---|---|---|---|
| Shortest | 15 minutes | 13 min 44 s | 1.09× shorter | |
| Middle (this run) | 60 minutes | 33 min 49 s | 1.77× shorter | |
| Longest | 250 minutes | 15 s | 980.39× shorter | |
| Other agents, middle request | ||||
| GPT 6 Astra | 60 minutes | 1 h 1 min | Within 5% | |
| GPT 5.6 Sol | 60 minutes | 1 h | Within 5% | |
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Data and citation
Upstream: Yang et al., 2026