VRS shots

I know that this is almost pure luck but it still made me do a double take... I went out to check an elevation yesterday with VRS (and before anyone starts yelling at this 0.1' was close enough for what I was looking for). I shot it as a three minute observed control point at around 11:00am and came back and did it again at around 4:00pm, and averaged the results. The standard deviation of the elevation came up as 0.000. I assumed I must have somehow managed to screw up a very simple procedure, so I went and reviewed the individual results - 6.216' at eleven and 6.217' at four. I then looked at another observed control point result on the same point from about six weeks ago - 6.235'. I don't know about the absolute accuracy of those numbers, but that's enough to reinforce my faith in the precision of our VRS data.