Tonedog, There are several things wrong with your thoughts when it comes to producing Bandogs or Swinfords. Breeding Bandogs is NOT like adding one trait to an already established tight bred line of purebred dogs. When one wants to add or enhance a specific trait to a tight bred line dogs, it works well to do an outcross to another line or even another breed and then select for that trait among the offspring produced in the F1 generation...and take those back into the orginal line of dogs to produce F2 dogs...and again selecting for that trait (should it show up it would be dominant...should it not show up then breed some half sibling F2 with some other F2 and selecting for those that show the enhanced desired trait)...and proceed from there by again going back into the original line repeatedly until you breed OUT the outcross percent by reducing the percent of the original breed in successive generations while maintaining the one desired trait...overtime producing a new line of dogs that is essentially the SAME as the original line of purebred dogs but with one enhanced trait. That however is NOT how Bandogs or Swinfords are produced. A Bandog and Swinford is DIFFERENT than BOTH of the origins...by being a COMPOSITE of both breeds. The Swinford specifically is to have the courage, speed, stamina, health, prey drive, fight drive, and general tenacity of the APBT while having the loyalty, pack instinct, power, and defense drive of the Mastiff. When selecting specimens to use one also has to look for good nerves as well. Generally, rank drive issues is not problem in the APBT or mastiff, but it doesn't hurt to be aware of such issues to be sure. For the record...I am past the F1 stages. In fact, I do NOT EVEN OWN a single APBT or a single Mastiff anymore and haven't for years now. We have four generations in our program. My point is...I am not going out of my way looking for a mastiff anymore. When I did though, I didn't just look for athleticism. I looked for both physical and mental attributes described earlier in this post.