The next article, #21, which I have written for Hard Air Magazine is online at....https://hardairmagazine.com/ham-columns/how-important-is-extreme-spread-to-accuracy/Is ES important?.... Yes, but other factors are even more important!.... Enjoy !!!Bob
Bob,That article has been the biggest eye opener for me HUGELY IMPORTANT. ❌Thank YOU for sharing all your profound insights and intelligent analyses with us!! 👍🏼 😊Scotchmo,would you briefly share how to calculate SD and what it really means? 😊Matthias
Would it not be the lower SD has the higher probability? The higher the SD the lesser probability?
That's a great comparison, Scott.... Would I be correct in saying that the SD is always lower than the ES, providing you are looking at a reasonable number of shots.... For example, if you are looking at 10 shots, if the ES is 10 fps, then the SD would be less than 10 fps.... If you looked at 100 shots with a typical bell-curve distribution of velocities with an ES of 10 fps, wouldn't the SD likely be about 3 fps?.... since 3 x an SD of 3 = 99.7%....Bob
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I get that.... So if we apply the idea of SD to estimating the range, or the windspeed, we would get the same thing.... We would have a prediction of how likely your next "guesstimate" is to the actual distance to the target, or how far the pellet will drift downrange, compared to the actual result.... These will typically be a bell-curve, so if over 100 range estimates you had an SD of 2%, then 99.7% of the time you should be able to estimate the range within 6%, correct?.... If over 100 estimates of the windspeed your SD was 10%, then 99.7% of the time you should be able to estimate the correct holdoff within 30%.... However, only 68.3% of the time would you get the range correct within 2%, or the drift correct within 10% (numbers for comparison only) . The point of my article was to give a feel for how important velocity variation is to the vertical stringing at the target.... and how that compares to the human error involved in estimating range and windage.... I hope I accomplished that?....BobPS, incidently, I used your calculator with a sample size of 2 shots, of 100 and 110 fps, and the SD was 7.07, while the ES was 10.... Increasing the number of shots to 20, with velocities all of 100 and 110, shrank the SD to just under 5.2 while the ES remained at 10.... I'm pretty sure the SD is always smaller than the ES.... It would appear, however, that an SD of 7 means that the velocity should be within plus or minus 7 fps, ie a total range of 14 fps, correct?.... In other words, an SD of 5 means that the ES would be 30, 99.7% of the time....RBS
It is also true that Statistics are like a Bikini.... What they reveal is enticing, but what they conceal is vital.... Bob