When I first began learning Mandarin and was struggling with some of the different pronunciations I heard 2 different representations of the "r" sound in pinyin. The first representation suggested to just treat identically to how you would treat an English "r" and native speakers will understand you well enough, and the other said it was closer to the "s" sound in the English word "measure".
Obviously these are two completely different and contradictory representations, and as an native English speaker I should have just ran with the first, but I grasped the latter almost instantly and have been pronouncing it in that way ever since (to myself in private, the only communication I ever have with native speakers is through text).
This has been fine for me, I've since heard numerous audio samples that use either or, which has lead me to believe that it didn't really matter. I even recall reading somewhere that the latter representation is common in northern dialects (citation needed).
But just now while watching this YouTube video at 0:45 the woman speaking says the word 别人 and then follows it up by saying 人 by itself. The first time she pronounces the "r" sound using the first method, nearly identical to the English "r". The second time she used the method I'm more familiar with, and I corroborate that the way she says it is exactly how I've learned to pronounce it.
So I guess the question I'm asking is, what is the history behind this distinction? Is it a north/south difference or is there more to the story?