Preprint
Form Rescued Is Not Content Gained: What Constrained Decoding Does to Accuracy, Why Published Studies Disagree About Its Sign, and the Parse-Failure Accounting That Decides the Small-Model Case
(c) 2026 Pranay Mahendrakar. Licensed under CC BY 4.0. Life of Research Constrained decoding masks every token that would break a grammar or a JSON schema, so the output always parses. Whether it also changes how often the answer is right is contested: one line of work reports that format…