Page 5 of 32.
Three detectors, three buyers, three very different standards of published evidence. Turnitin arrives through a university's admin settings, Originality.ai is bought with a card on a credit plan, and Copyleaks reaches students through LMS integrations. What each one measures, and which one is likely to score your work.
Drafting stopped being the bottleneck the week the agency adopted a model. The editor became the bottleneck the same week, and most teams never rebuilt the process around that. This is the operational version: the three points a human has to occupy, the decisions worth making once across every client, and the work that resists standardization no matter how good the system gets.
The step that decides everything happens before any rewriting tool opens: reading what your own module actually permits, which is almost never set at university level. Then comes the editing method for an essay specifically, which is a different document from a journal manuscript and rewards a different order of work.
A rewriting pass reads a citation as ordinary words, so surnames swap places, years vanish, et al. thresholds move and merged sentences leave references pointing at nothing. Here is each failure, what it looks like on the page, and the check that catches all of them.
Two of these ten detectors publish the same 99.98% headline accuracy figure. One names the researchers behind it and breaks its false positive rate out by genre. The other names no test at all. Ten tools placed on four axes: who buys them, what they claim, what evidence sits behind the claim, and what the report actually shows, plus the process-tracking model that may replace scoring altogether.
Most desk rejections happen before a reviewer is ever chosen, in the few minutes an editor spends on your title, abstract and first paragraph. Here is what that first read is actually checking for, and the one read-through that catches most of the problems before you submit.