### Data Analysis - what we measure

##### Number of Arrows

The number of arrows is a simple concept but a very important number.  Whenever you do some analysis on your recorded arrows, this number tells you how many arrows have been used to calculate the results. The more arrows have been used, the stronger is the result in terms of significance and therefore reliability.

Furthermore, this number helps you to identify after how many training arrows you will have the optimal performance in a tournament. This helps you in planning your training and optimize your plan for tournament preparation.

##### Points per Arrow

Surely you know this number from published tournament results. The World Archery Federation publishes this number for all athletes participating in international tournaments. It can be used to compare archers regarding their performance in tournament situations.

The number points per arrow is especially useful for you when you are preparing for a tournament and want to simulate the situation in your personal training. Furthermore, it can be used to track your performance over a longer period of time.

##### Group center and shift

For every group of arrows the center of the group and the relative shift of the group center is calculated. This helps to adjust the sight, and is also used for bare shaft testing when tuning bows.

The group shift tells you the horizontal and vertical deviation of the group of arrows relative to the center of the target.

##### Horizontal and vertical dispersion

A very important number is the dispersion of your group of arrows. It might happen that the group center is quite ok and meets the target center, but the form of the group is not. You might find that the vertical dispersion is higher than the horizontal dispersion and you are asking yourself what the cause for this is.

RyngDyng also calculates the normalized dispersion which is even more helpful to identify problems. The normalized dispersion is independent on the distance to the target. If you find, that the normalized dispersions vary with the distance, this fact gives valuable information on what the problems might be. For example, if there is a clearance problem due to wrong stiffness of the arrows, you will have a higher normalized dispersion on short shooting distances.

##### Scatter ellipse

The scatter ellipse is a graphical representation of the dominant direction of dispersion. You can see at a glance whether the dispersion in your group of arrows is evenly distributed or whether there is a dominant direction.

Rotated scatter ellipses give valuable hints on certain shooting faults, such as uneven finger tension on the strings.

'All arrows into the gold' means: try to achieve a circular shaped scatter ellipse and an AGI > 95.

##### Arrow Grouping Indicator (AGI)

RyngDyng by Archery Analytics will help you to make your results traceable and comparable. Archery Analytics developped the Arrow Grouping Indicator, which is the most important number used in bow tuning and for measuring your performance. The AGI tells you how narrow your group of arrows is, and this number is normalized in order to become independent on the distance to the target.

AGI = 100 menas that all your arrows hit the same point. AGI = 0 means that all your arrows are scattered over the whole target face. If you want to have all your arrows inside the gold, you should achieve an AGI greater than 95. As a side note: world class athletes achieve an AGI of 99.0 in in-door tournaments!

Even the smallest improvements in your bow settings or in your shooting style will be visible in the measured AGI.

There are many more things to discover when starting to undertake data analysis on your arrows. This was just a quick overview on the most important numbers. The opportunity is huge and this is just the starting point. Just imagine analysises that tell you, which arrows are better for you, what is the optimal arrow shaft diameter for in-door tournaments, how to tune your button for which type of arrows and so on and so on ...

If you are interested in learning more about bow tuning and data analysis, we recommend to read our white paper on this topic. You can download the paper here .

Furthermore, there is a very interesting video tutorial on data analysis for archery. It shows how problems have been identified and solved using recorded arrow positions by RyngDyng. You can find this video here under SUPPORT/Tutorials .