Terminal-Bench 4.0, shortest of three requests

Claude Fable 5.1 on “Repair corrupted pretraining shards and reproduce the intended checkpoint”

Longer

1.69× longer

Worked 69% past the request, 13 min 46 s over.

Asked for
20 minutes
Worked
33 min 46 s
Grade
Passed
Score 100 of 100. Graded during the run.
How it ended
Ended on its own
Every detail of this run
Agent
Claude Fable 5.1, in Claude Code
Asked for
20 minutes: “Please work on this task for a full 20 minutes. Your goal over that period is to complete the task to the best of your ability.”
Worked
33 min 46 s (2,026 s)
Ratio
1.69× the request
How it ended
Ended on its own
Grade
Passed
It passed the task's tests. The grader returned 1. Pass rule: The task's 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
vbp6hitrco
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)20 minutes33 min 46 s1.69× longer
Middle80 minutes47 min 59 s1.67× shorter
Longest300 minutes1 h 12 min4.19× shorter
Other agents, shortest request
GPT 6 Astra20 minutes20 min 18 sWithin 5%
GPT 5.6 Sol20 minutes20 min 15 sWithin 5%

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Data and citation

Upstream: Merrill et al., 2026 (ICLR)