HarnessOpt-Bench - BrowseComp-Plus: leaderboard
Metric: Normalized gain ((held-out score minus seed score) / (1 minus seed score); negative when the nominated harness is worse than the seed; mean over the contestant's optimization rounds, each held-out case scored three times; BrowseComp-Plus deep-research question answering with a deepseek-v4-flash target agent; seed held-out score 0.462, 66 test cases; the optimizer edits the seed harness under fixed development and validation evaluation budgets and never sees the test partition). Source: arxiv.org. Saturation forecast: Around March 2027. 10 models tracked.
Top models
| # | Model | Score |
|---|---|---|
| 1 | Claude Opus 5 | 0.48 |
| 2 | Kimi K3 | 0.16 |
| 3 | Claude Sonnet 5 | 0.15 |
| 4 | GPT-5.6 Sol | 0.09 |
| 5 | GPT-5.6 Terra | 0.02 |
Interactive version: theaggregate.ai/benchmark?slug=harnessopt-bench-browsecomp-plus · How It Works · Data refreshed daily, snapshot 2026-09-29.