YC-Bench, middle of three requests

GPT 5.6 Sol on “Run the current one-year startup simulation, official seed 1”

Shorter

1.72× shorter

Stopped at 58% of the time asked, 12 min 33 s short.

Asked

Worked

Safety cutoff 4 h 10 min, off the scale

Every detail of this run

Agent: GPT 5.6 Sol, in Codex
Benchmark: YC-Bench
Task: Run the current one-year startup simulation, official seed 1
Asked for: 30 minutes: “Please work on this task for a full 30 minutes. Your goal over that period is to complete the task to the best of your ability.”
Worked: 17 min 27 s (1,047 s)
Ratio: 0.58× the request
How it ended: Ended on its own
Grade: 496702.73; Final company funds in US dollars, starting from $200,000 (negative if the company goes bankrupt). No official pass rule.
Score: Final funds $496,702.73; Graded afterwards. The paper's value.
Wording: The standard sentence, used from 4 September 2026.
Run id: ifzua7hijp
Data release: 26 Sep 2026

The other requests for GPT 5.6 Sol on this task, and the other agents at this request
Sol on this task	Asked	Worked	Result
Shortest	8 minutes	8 min 17 s	Within 5%
Middle (this run)	30 minutes	17 min 27 s	1.72× shorter
Longest	125 minutes	35 min 7 s	3.56× shorter
Other agents, middle request
GPT 6 Astra	30 minutes	6 min 3 s	4.95× shorter
Claude Fable 5.1	30 minutes	28 min 20 s	1.06× shorter

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Data and citation