At a basic level, I'm interested in how pirates in the 17th and early 18th century (the so-called golden age of piracy) kept records. My hypothesis is that some kind of accounting system would have been necessary at some level in order to trade competitively in sympathetic markets, to intercept merchant ships, to some extent in order to maintain a semblance of fairness among the crew, and in the case of privateers, to travel unharassed in certain maritime jurisdictions. While these records may not have been kept on paper, and it is even possible that most pirates were able to get by almost entirely by chance, whether because of the sheer number of merchant vessels at the time or survivorship bias, I would be very surprised if they did not exist at all (in spite of the obvious risks if such records fell into the wrong hands, whether those of an especially treacherous contemporary or someone today who may be inclined to hunt the historical bounty of pirates for perhaps selfish reasons.)
I can see two classical approaches to this question. First would be to examine accounting practices that pirates may have learned in their early careers, whether as merchant marines or in the navy or elsewhere, and examine which of those might have survived the transition to piracy or privateering. The second approach would be to start with (presumably somewhat well-kept) records kept by various navies and merchant companies, and to iteratively enumerate and carefully examine 'knowledge gaps'.
However, I'm more than a little bothered by the asymmetry here; one approach seems considerably more informative than the other, and less susceptible to individual idiosyncrasies to boot. On the other hand, there are plenty of idiosyncrasies in the sampling bias of either record. I'd be interested in hearing other perspectives on the nature of these biases before delving perhaps too deeply into this topic. (Are there other biases that might be worth addressing as well? What other primary sources might be available?)