How come Golden Retrievers love tennis balls?

Not just retrievers love Tennis balls but like Carole E said, retrievers were bred to have soft mouths and not hurt the game they were bringing back. My poodle loves tennis balls and surely would have no idea what to do with a basketball!

Goldens were bred for field work, returning downed birds to the humter, and like most retrievers have a natural tendency to hold things in their mouths. A tennis ball is easy to pick up and carry around, and has some "give" to it when in their mouths so probably feels more like "game" than a basketball which is too larger to pick up.

My Golden Retriever mix loves tennis balls too. It is just the right size for her mouth, so it is her favorite type of ball. :)

Golden retrievers like to carry things in their mouths, probably has to do with their inherited need to retrieve things. The tennis ball is probably just the right size and pliability that is easy for the GR to carry for long periods of time.

Their just the right size for their mouths and don't fall apart easy.

Dogs love tennis balls because it fits just right in their mouth and it has some give to it unlike balls that are bigger and hard

Most dogs like the tennis balls because they have so give to them, their just the right size for their mouth. Basket balls are to big and hard