How to check in JigSaw if an eclipse will affect a group of charts?

Use the drop down menu in JigSaw under the Research Option and select Add a Point. This will open the Add a Point window which will allow you to add either a midpoint or a particular degree to your entire data set with which you are working. Enter the degree of the eclipse (or fixed point). Now, open the main research scene and select the point you have added along with the natal points with which you wish to work. Select the Phases and Aspect option and tell Jigsaw which aspects you want to use for your search. Display your results as a table. You can then FILTER to create a subset of charts as you may secondly require. This will show you how many members of your group are being affected by the eclipse.