They're as accurate as you can get without having every single game every played in the data.
The best answer to this problem is just more uploads. More data = more accuracy and the more people uploading the less often people can selectively upload games, since other people will be uploading games they're playing in.
If you want to PM me with any specific player pages you are wary of we will look into them, but the best way to prevent selective uploading is to encourage more people to...
Posted: Feb 05, 2015