your opinions of why we cross the way we do...

Lots of good points on this discussion, like crib just said. It takes many years of line breeding to develop a strain and you get to a point where you are splitting hairs to get better dogs and then you get to a point that you need a touch of new blood added to the breeding program. The sensible thing to do is to find a dog that has at least 50% of your bloodline and the other 50% to be somewhat related and that dog needs to bring something to the program that is an enhancement to your dogs. This dog needs to be of high quality as well as its parents and these dogs should look and act, hunt like your dogs. This is so that you will gain from this breeding (hopefully). Also, If you are interested in a male pup to add to your program then you need to keep as many males from this cross that you can because if you are serious about improving your line, this is what you do. The reason is obvious. You want to cull those male pups over at least one year so that you wind up with the best possible choice for the breeding program. When you outcross a line that has been bred like this you will lose a lot of what has been bred for generations in that one outcross.

My vote is to keep them pure. Hunt the cur breed you like best to strike with and catch with your favorite catch breed.

When you cross a cur or hound with a catch dog your percentage of getting what you want will probably be somewhat low and very diversified. Then you will need to select the best from this and keep it going to increase the percentage of what you are looking for...