Reply To: What is standard deviation?
+\- one standard deviation means approximately 67% of a population (shot string in this case) will be within that value. So for example, a 100 shot string with a standard deviation of 20 fps will have roughly 33 shots greater than 20 fps from the population average. Standard deviation is a simple statistical calculation, but in my opinion is not as helpful as extreme spread. Most guys want to know the total shot variation to achieve the best possible accuracy and this comes from extreme spread.