ProgramBench, shortest of three requests

Claude Fable 5.1 on “tomarrell/wrapcheck”

Longer

7.04× longer

Worked 604% past the request, 1 h 31 min over.

Asked for
15 minutes
Worked
1 h 46 min
Grade
Did not pass
Score 68.5 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
15 minutes: “Please work on this task for a full 15 minutes. Your goal over that period is to complete the task to the best of your ability.”
Worked
1 h 46 min (6,338 s)
Ratio
7.04× the request
How it ended
Ended on its own
Grade
Did not pass
It did not pass every hidden test. The grader returned 0.685. Pass rule: Resolved: every hidden test passes.
Score
68.5 of 100
Graded afterwards. The paper's value.
Wording
The standard sentence, used from 4 September 2026.
Run id
2djrdzzno7
Data release
26 Sep 2026
The other requests for Claude Fable 5.1 on this task, and the other agents at this request
Fable on this taskAskedWorkedSplitResult
Shortest (this run)15 minutes1 h 46 min7.04× longer
Middle60 minutes8 h 20 min8.33× longer
Longest250 minutes8 h 20 min2.00× longer
Other agents, shortest request
GPT 6 Astra15 minutes15 min 27 sWithin 5%
GPT 5.6 Sol15 minutes26 min 38 s1.78× longer

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Data and citation

Upstream: Yang et al., 2026