Drawboring a mortise-and-tenon joint means offsetting the hole in the tenon so that the pin pulls the parts together tightly—and permanently. If your tenon shoulders are square, your assembly will be, too. You'll no longer need clamps, which can damage workpieces and pull them out of square. Your doors will be square and will fit better. And your workflow will improve, because you will no longer have to wait for glue to dry. Just pin the joints and keep on moving.