Anthropic's Opus 5.5 Leaves Detectable Linguistic Fingerprint Despite Efficiency Push

Anthropic's Claude Opus 5.5, released on September 22, 2026, achieves performance parity with its flagship Fable 5.1 model at 40% lower operational cost, but independent linguistic analysis reveals the model exhibits 2,548 distinct word patterns that betray its artificial origin—a trade-off the company appears to have accepted in pursuit of broader accessibility.