Yes, include regular and extra duty. My list included Penn regular and extra duty but missed Wilson and maybe others,
Would first begin with a poll of the most commonly used balls. The 5 brands listed listed on TW site.
The world's #1 online tennis shop will certainly be representative of what is being used out on American courts .
Balls that are used for match play. Omit the kids balls (Gamma), pressureless balls, Penn Coach, etc.
Include a polling option for "Others not listed".
So we are down to three major brands being sold on TW site. Penn, Wilson and Dunlop.
Plus the other two brands Tecnifibre (3 models being sold) and Babolat (only 1 model being sold).
It should be doable with about 18 polling options. These would be the brands sold on TW.
Not sure why TW does not sell Yonex.
www.tennis-warehouse.com