Before last contest that I coded, I had 1670, than I lost 77 points of my rate and before last contest I was a cyan. Than, my friend noticed me, that 21.11 would be a div2 contest! I thought and I solved a problem of the humanity — if I wouldn't write a contest div2, I will increase more rate on div3!!! How simple and geniously it is. I know, that this kind of trick many of CF users know, but... the key is in the practice this trick.
So, will watch what I will have after div3:)