I have put together two tools.
A calculator to set up your equipment starting from your own measurements, and a quiz to help you understand where you are most likely leaving points on the target. They are free, and they stay free.
Draw length and arrow length
Draw length and arrow length are calculated using the standard industry method: a reliable estimate to build from. Spine, on the other hand, is not something I will guess for you. It is selected from the manufacturer's chart, crossing your actual draw weight against your arrow length, and it is specific to each shaft model. I have linked the right source below.
Open the dedicated calculator page →
cut past draw length, never shorter–
What about spine?
Spine is not something you can really calculate on paper. You select it from the manufacturer's chart, crossing your actual draw weight against your arrow length, and the chart is specific to each shaft model. Then you fine-tune it with a bare shaft test. I would rather send you to the right source than give you a number that might be wrong.
Open the official Easton selector →Where are you losing points?
Seven questions about your shot. At the end I will tell you which area is, in all likelihood, costing you the most, and where it makes sense to start. This is a serious orientation, not a full diagnosis: that requires the data.
Your most likely critical area: –
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This quiz gives you a direction based on how you perceive your own shot. Knowing what is really happening requires data: reaction times, aiming stability in millimetres, consistency across a full session. That is exactly what I measure in the video analysis.
Your arrow grouping
Adjust the variables and watch the group tighten. This is what I measure: every variable you stabilise removes dispersion, and dispersion is what separates a good score from a poor one.
This is a simulation, not a real measurement. But the principle is accurate: the difference between archers is not "shooting well sometimes," it is removing dispersion, consistently. And dispersion can be measured.
Want to know what the numbers say about your shot?
The tools above give you a direction. When you want the real read, with the data, write to me: I read every message and reply personally.
Write to me