There’s info online you can Giggle regarding the reliability of New Testament manuscripts compared to similar documents of antiquity. Here’s a good summary, but I saw an image on Facebook (see note way below) that diagramed the comparisons.
It’s an interesting phenomenon to note, but in most cases it won’t do much to convince skeptics. There’s a good reason for this. If, say, historians found out that Aristotle’s Poetics was written by someone else, or a group of someone elses. His (or their) ideas on ethics, metaphysics, and logic would not be diminished. That is to say that the value of the text doesn’t depend much on who wrote it. What was said is what matters.
Similarly, if it was found out that an historian like Tacitus was really a composite of other writers, it may cast some doubt on what was written in The Histories, but it won’t be much skin of the nose of most people today. Many of the events recorded may still be verifiable, but even if the author was inaccurate the consequences to everyday life are minor.
But the standards for the New Testament are different, because even if the manuscripts are reliable it doesn’t answer the question as to whether the New Testament events occurred. It proves, for example, that the copies agree with themselves but not that the recorded events described, specifically the supernatural events, had actually passed. Textual reliability is irrelevant if someone believes the supernatural is outright nonexistent. A skeptic would have to first have to believe that supernatural events, like the resurrection, are at least possible imprimus. The text doesn’t have a bearing on whether they are possible. They merely claim they occurred some time in the past.
The fact of manuscript reliability may have some effect on the skeptic if it removes a defeater for belief—as in, part of the disbelief is held in false information, particularly that New Testament documents are not reliable. But as far as “making believers” out of atheists, a lot more needs to occur, cognitively and a-cognitively, that an historical factoid.
*I originally had a diagram of New Testament manuscript reliability created by Mark Barry. I had emailed him about using the image but he had since taken it down because, in light of recent conversations, he needed to do more research before officially confirming the info in the diagram. He didn’t mention Bootsy Collins.