I do not know where you got that information but wherever you got it, the official documentation is more reliable:
If you go to another site bypassing TOR, on the same computer, then the two sites may be able to compare notes, and realize you are probably the same person.
Panopticlick says that 85% of visitors are uniquely identifiable, by it's method. Another site, https://valve.github.io/fingerprintjs/ , appears to dig deeper - installed plugins, giving it "94% accuracy".
Ironically, since only a small proportion of users do things like blocking cookies, etc, doing so will actually INCREASE your uniqueness, and make you easier to identify with these techniques.