Using a rope or bar handle attached to a cable that's set above your head, do a set with an upright torso while standing about 4-5 feet back from the cable column (8-15 reps).
Then do a set with your torso parallel to the floor.
The point of maximal mechanical tension is when your arms form a 90-degree angle to the cable. So, upright torso pulldowns focus more on training you in the shortened to mid-range aspects of shoulder extension. Performing them with your torso parallel to the floor focuses more on the lengthened to mid-range.
There's nothing more frustrating than committing to a training program that doesn't pan out. This is equally true for an athlete who might work hard yet still falls short of his expectations and the strength coach whose biggest satisfaction comes from the great strides his athletes make.