In statistics, the 68–95–99.7 rule, also known as the empirical rule, is a shorthand used to remember the percentage of values that lie within a band around the mean in a normal distribution with a width of two, four and six standard deviations, respectively; 
More accurately, 68.27%, 95.45% and 99.73% of the values lie within one, two and three standard deviations of the mean, respectively. Over 3 deviations and the odds reduce tremendously. Deviations in context are 'coincidences' as related to Q.
en.wikipedia.org/wiki/68%E2%80%…
en.wikipedia.org/wiki/68%E2%80%…
When you go back and look at what would widely be considered a 'coincidence deviation' or a 'confirmation deviation' Re: Q- you would find no less than 10 times where there has been a deviation that would fall into one of those two categories. In short- Q-Group is legit.
