When LLMs Lose the Plot: Diagnosing Reasoning Instability at Inference Time
Opening — Why this matters now If you work with large language models long enough, you start noticing a familiar failure mode. The model doesn’t just answer incorrectly—it loses the thread. Halfway through a chain-of-thought, something snaps. The reasoning drifts, doubles back, contradicts itself, and eventually lands somewhere implausible. Traditional evaluation misses this. Accuracy checks only look at the final answer, long after the damage is done. Confidence scores are static and blunt. Multi-sample techniques are expensive and retrospective. What’s missing is a process-level diagnostic—a way to tell, during inference, whether reasoning is stabilizing or quietly unraveling. ...