DDog3 is a little over a year old. Rescued from a drug dealer trying to sell her for drug money, she is unsurprisingly staffie, most likely crossed with whippet. She has a very fine staffie head (though still unmistakably staffie) but from the neck down is like a heavy set whippet. No sign of collie in her at all, apart from her lying down and eyeing my other dogs up before taking off after them.
Obviously we will never know exactly what she is, but I can't think of any other breed that shows this behaviour, which is exhibited in a daily basis (and both my boys are spaniels so no lying down and bent eyeing there for her to learn from ;))