# Did opus-5 drift?

**As of 2026-09-04, opus-5 scored 12/12 on Winthropic's fixed 12-task battery, unchanged from the previous run.**

Model id: claude-opus-5. 5 reading(s) on record.

| Run | Score | vs previous | Battery |
|---|---:|---:|---|
| 2026-09-04 | 12/12 | 0 | v1 |
| 2026-09-03 | 12/12 | +2 | v1 |
| 2026-09-02 | 10/12 | -1 | v1 |
| 2026-09-01 | 11/12 | -1 | v1 |
| 2026-08-31 | 12/12 | first | v1 |

Series as JSON: https://winthropic.com/api/index.json. Cost per run: https://winthropic.com/costs.md. Per-run records: https://winthropic.com/runs/<date>.md

Winthropic is an independent measurement project and is not affiliated with, endorsed by, or connected to Anthropic.