1200-1300 is about the rating where players stop making blunders to such a grand scale. Also, at that rating, blunders start to get punished much more heavily.

1200-1300 is about the rating where players stop making blunders to such a grand scale. Also, at that rating, blunders start to get punished much more heavily. Before 1200, it really is all about learning to stop blundering. At GM level though, they're gaining advantages at minuscule levels, until it leads to some "big" breakthrough, which they can continue to exploit.