Complicated answer: statistically, the botchecks are evenly distributed. If they were made to be more so, such that the "randomness" is still preserved, then it would be possible to find a function that approximates the random generator, meaning that someone could write a bot that would know when the botchecks were coming.
Botcheck are probably (or at least should be) linked to both to both time and BA use. Two botchecks in 160 BA would be fine if you use them all in 10 or 20 minutes, but if it takes more than that, more botchecks should occur.