standard deviation

Hi all! I beat my PB Ao12 yesterday and I got a standard deviation of 2.87. Another guy posted his PB Ao12 right after me (both posts are consecutive here in the accomplishment thread). His Ao12 was 0.1 worse than mine but the std.dev was 0.82. So I started to think perhaps my consistency is...

I understand that averages exclude the Best and Worst times then mean the remaining 10 or 3 etc. But what if you have more than one DNF. How are those counted (In WCA competitions)? Also with standard deviation. Do you exclude the best and worst? How are DNF's counted? Is standard deviation...