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Archived response·drift

Claude Opus 5 on D4, 2026-09-11

Scored answered · correct · format ok — correct if the response answers 9.9.

Model: anthropic/claude-opus-5
pinned anthropic/claude-opus-5-20260723; alias resolved to anthropic/claude-opus-5-20260723 at 2026-09-11 09:00:01 UTC (matches the pin)
Prompt: D4 (drift)
Date: 2026-09-11 · run 20260911T090002Z-da0dd3 · scorer v1
Permalink: https://modeldrift.watch/r/2026-09-11/D4/anthropic/claude-opus-5/

Prompt D4sent verbatim

Which is larger, 9.11 or 9.9? Reply with only the larger number.

Why this prompt Historic decimal failure; stable ground truth 9.9.

Scored: answered · correct · format ok
Received: 2026-09-11 09:01:18 UTC
Run: 20260911T090002Z-da0dd3
Served by: Claude Platform on AWS · HTTP 200 · finish stop
Size: 3 characters · 15 tokens out incl. hidden reasoning · 5.1 s

Highlighted: every candidate value found (1); exactly one is required.

9.9

End of response · 1 lines · 3 characters · sha256 1b5c15d377f5e8d01d00a7c34e882c5395db95fd3ba73c7725131c86fdb7ae0a

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