It was expalined to me that the first cross to create the BMC began with a bullmastiff male and a black and tan gyp. It was expalined to me that thy crossed these too because of size and cold nose. It also somewhat explains the reverse colorins.
I thank you got it right. It is a man down the street that has a cross of a bullmastiff and pit bull and the dog looks just like a black mouth cur. Thanks