While most dogs do tend to choose their own spot, which is why that one or two areas in the backyard are always brown, you can move the spot to somewhere outside of your yard. There are several methods of doing so, all of which can be used with similar results. With consistent effort, you can put an end to this problem in less than a month.
Depending on which of the methods you choose to try, the list of items you need may include:
As with most forms of training, the fewer distractions your dog must deal with the easier it will be for him to focus on what you are trying to teach him. The big thing here is that you need to have an area picked out where it is "okay" for him to relieve himself. With proper training, you can train him to use this area and even further to the point at which you can be out far away from his home and he will still poop on command.