There is a certain misguided school of thought that considers the game of lawn tennis to have been developed in the last century from that of Court or Real tennis. This is quite untrue. The game was actually developed in order to ensure the proper evolution of the Flat-Coated Retriever.
Whilst a beautiful flowing black coat and a rather snipey muzzle were relatively easy to breed for from existing Retriever stock the first developers of the breed were determined to ensure that an innate desire to perform extraordinary retrieving and juggling feats should be an essential characteristic of the breed.

Therefore, in a somewhat clandestine fashion, many of the owners of the great English Country Houses began to set aside rectangular sections of their lawns so that they could try out a variety of 'retrieving aids'. Many 'retrieving aids' were invented, each developer claiming to have 'the best' . In order to carry out objective trials it was decreed that white lines should be painted around the retrieving area and an agility obstacle (in the form of a long net) should be placed across it. Many were the House Parties devoted to the trials of 'retrieving aids' until a clear overall winner emerged in the form of a sort of yellowish soft furry ball. This seemed - and indeed has since proved - to be ideal for the recently created breed.

Sadly, some of the less sophisticated of those who had tested the retrieving aids adopted the new tennis ball as a sort of icon around which they developed a whole sporting industry - incidentally allowing use to be made of a redundant piece of real estate in the Wimbledon area.

The one thing that the early testers did find (and this is the moral of this tale] was that with a yellow ball it was necessary to have a black dog - it being so much harder in retrieval trials to discern the exact moment when a yellow dog recovers a yellow ball! Therefore from that day forward yellow in a flatcoat has been banned from the breed standard.