alt Hacker NewsTor Browser will not even hide the OS you're using from javascript... so if you're on Linux, you are automatically more identifiable than >97% of people.
Also, that EFF site only checks against other people who visited the same site, so the results are skewed IMO. The other comment that links to creepjs is what I consider the best available open source tool.
Yes, the anonymization is not perfect but it's the best you can get.
You don't have to compare your fingerprint with other visitors. Just have a look at the detailed information to understand which things reveal your identity the most.