Fable 5 median thinking declined in August
The gist
A researcher says Fable 5's median thinking tokens fell sharply in August versus July.
The dispute is whether users got a cheaper inference regime, not a nerfed model.
How it unfolded
- Jul 1, 2026Anthropic restored availability to Fable 5.
- Sep 6, 2026 -14, 202651 scored runs of a 276-case tool-calling suite across 20 models were conducted, plus an execution-verified coding bench and a 1M-token needle test.
- Sep 15, 2026A Hugging Face discussion post reported that DavidAU's TURBO-Fable-Cold-Fusion-735-882 with thinking off set an all-time record of 268/276 at roughly half the wall-clock of any thinking run.