Don't get too wrapped around the axle when it comes to ES and SD. I can think of a couple of pitfalls.
For example, guys new to this tend to have new chronographs with modern electronics. In spite of them being inexpensive, they tend to have very fast clock speeds and while a cheap chrono may not have perfect accuracy, it is likely to have high precision. That means that your ES data might appear to be worse than the old timer shooting next to you who purchased his chronograph 25 years ago and paid a fortune for it so he's not about to retire old reliable. But in truth his real performance may not be any better than yours even if his data looks like it is. The reason is that your new cheap gear is better than his antique expensive gear. So be aware of that possibility.
As someone who received quite a bit of education in physics, I'll say that Jarhead6870's examples of ES vs change in POI make a lot of sense. However, my careful testing shows much less correlation between ES/SD and POI than I would expect. I keep data on thousands of 5-shot test groups measured using a scanner and On Target scoring software. Many of my best groups exhibit relatively poor ES/SD numbers and, conversely, I have plenty of poor groups associated with very low ES/SD numbers. In other words, for reasons I can't explain, my real world results don't always match the theory; therefore, even though I record ES/SD for every group, I put more emphasis on Mean Radius and Deviation From Aim Point results on the actual target than I do on my chronograph data.
Having said that, my educational background just won't let me ignore ES/SD and I continue to chase that goal too. If our sport were easy, everyone would be doing it.
For example, guys new to this tend to have new chronographs with modern electronics. In spite of them being inexpensive, they tend to have very fast clock speeds and while a cheap chrono may not have perfect accuracy, it is likely to have high precision. That means that your ES data might appear to be worse than the old timer shooting next to you who purchased his chronograph 25 years ago and paid a fortune for it so he's not about to retire old reliable. But in truth his real performance may not be any better than yours even if his data looks like it is. The reason is that your new cheap gear is better than his antique expensive gear. So be aware of that possibility.
As someone who received quite a bit of education in physics, I'll say that Jarhead6870's examples of ES vs change in POI make a lot of sense. However, my careful testing shows much less correlation between ES/SD and POI than I would expect. I keep data on thousands of 5-shot test groups measured using a scanner and On Target scoring software. Many of my best groups exhibit relatively poor ES/SD numbers and, conversely, I have plenty of poor groups associated with very low ES/SD numbers. In other words, for reasons I can't explain, my real world results don't always match the theory; therefore, even though I record ES/SD for every group, I put more emphasis on Mean Radius and Deviation From Aim Point results on the actual target than I do on my chronograph data.
Having said that, my educational background just won't let me ignore ES/SD and I continue to chase that goal too. If our sport were easy, everyone would be doing it.
