On April 23, 2026, Anthropic published a postmortem. It described three product and harness problems that affected recent Claude runs.
We reran 17 BOTSv3 questions under matched conditions, after the problem window. Earlier runs had flagged these 17 for memorized answers. We asked whether those problems explain how Opus 4.6 and Opus 4.7 differ on them.
With tools, Opus 4.6 at high effort solved 14 of the 17. Opus 4.7 at high effort solved 5. Both used the same questions and the same setup.
Without tools, Opus 4.6 solved 6 of the 17 at high effort and 7 at default effort. Opus 4.7 solved 1 at both settings. Its one solve needs only general knowledge.
The timing of the problems does not explain the gap by itself. Model behavior and tool use likely account for the rest. Host configuration changes around April 17 may also matter for runs outside our isolated harness. We could not measure that effect.
We do not publish the full rerun, because it quotes the questions and answers.