How AI detectors actually work (and how to beat them without lying)

Most commercial AI detectors reduce your text to three signals: perplexity, burstiness, and vocabulary uniformity. Perplexity measures how surprising each token is given the preceding context — human prose is bumpier. Burstiness measures variation in sentence length — humans mix long and short; LLMs default to a narrow middle. Vocabulary uniformity captures how often the same adjective, connective, or sentence opener recurs — LLMs over-use words like "leverage", "delve into", and "it is worth noting that". A polish tool that simply replaces synonyms will not help: detectors do not look at word identity, they look at distributional patterns. What helps is real editing — breaking long sentences, cutting empty flourishes, varying your opener, and keeping technical terms precisely where they belong. This is what Polishly is built to do: not disguise your text, but actually improve it. The "bonus" is that better writing reads as more human because it is.