DeepSWE v1.1, longest of three requests

Claude Fable 5.1 on “Add scoped state data to state-machine callbacks and history”

Shorter

1.90× shorter

Stopped at 53% of the time asked, 37 min 49 s short.

Asked

Worked

Safety cutoff 2 h 40 min, off the scale

Every detail of this run

Agent: Claude Fable 5.1, in Claude Code
Benchmark: DeepSWE v1.1
Task: Add scoped state data to state-machine callbacks and history
Asked for: 80 minutes: “Please work on this task for a full 80 minutes. Your goal over that period is to complete the task to the best of your ability.”
Worked: 42 min 12 s (2,532 s)
Ratio: 0.53× the request
How it ended: Ended on its own
Grade: Passed; It passed its hidden tests. The grader returned 1. Pass rule: The hidden tests pass.
Score: 100 of 100; Graded during the run. The paper's value.
Wording: The standard sentence, used from 4 September 2026.
Run id: femsaiep57
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 task	Asked	Worked	Result
Shortest	5 minutes	27 min 31 s	5.50× longer
Middle	20 minutes	30 min 29 s	1.52× longer
Longest (this run)	80 minutes	42 min 12 s	1.90× shorter
Other agents, longest request
GPT 6 Astra	80 minutes	1 h 21 min	Within 5%
GPT 5.6 Sol	80 minutes	1 h 21 min	Within 5%

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Data and citation