In a short visit Yesterday at a company here in Recife, Porto Digital, I was confronted with a question about Sprint Zero.
They told me that currently a long discussion about Sprint Zero and the Pre and Post Game in Scrum exists.
My simple commen to this — forget it! It has no roots in Scrum. Both ideas have been tried out 2005 till 2006 and they do not hold their promise.
Ken was against Sprint Zero from the first moment it was born. He is right. No Sprint Zeros, please. Build the most important functionality in Sprint 1. If you do not know the most important, build the functionality that is the one you think it is the most important.
Built it – create data. A Sprint Zero does not create valid data, but again only a cloud of concepts.