I've just now noticed that win and loss statistics per deck don't include friendly games. This is probably by design, but personally I wish that friendly games were included. If I have a wacky deck idea, I like to test it out with friendly games first to see how it goes, and the deck statistics are just what I would need. (Also, I tend to play friendly games when we're close to an update, because I don't want to be in the middle of a real game when all of my and my opponents' cards change :P)