It is something that I am correcting in my throw as we speak. As a result of seeing myself on the slow mo video. I was really curious why my chest looked so "up" or "out" as the disc passed my chest, and the disc was even striking my chest as it passed. The, the disc in the snap position seemed so "popped out" from my chest. Even though the snap was correct, it just looked odd.
Blake had always told me for the reach-back to work correctly the arm must, "hinge" into the reach-back position. The arm does not come "across" the shoulder level, typically the arm is swung up slightly from below to the level position, and the right shoulder will actually "fold" and drop slightly at the farthest point of the reachback as the shoulders coil. As result the shoulder joint is properly hinged where the upper arm is underneath the shoulder joint through the pull.
If you try both pull backs, one with a level plane and one where the disc swings up from below it is immediately apparent there is a tremendous difference in the way your lead shoulder becomes loaded. In the straight back position there will be a need to open the lead shoulder on the finish, or "come over the top" slightly".
In the hinged position the disc can be pulled slightly below the lead shoulder with the shoulder more static. In the position the chest is more "over" the pull line. The throw feels much more linear, and the hips can swing clear without a massive foot pivot that is necessary with the truly flat flat throw that requires a much more rotatory finish. An "across" pull back will create turn over torque that will become worse the power you apply to it. The hard you throw, the more likely the disc is to flip when you did not intend it to flip.
The hinged position is much more suited to hyser power, and if the pull of the arm is kept under the shoulder joint properly creates no torque to flip the disc. There are only a hand full of good players who do *do not* hinge the arm going back. Feldberg nearly touches his knee with the disc as he swings under, as he exaggerates his hyser style. Walt Haney does it with a tiny little dip of his shoulder (you really have to look for it). You can also look a Schweberger, Russell, or just about any European player. Many start with the disc in the forward "primed" position and swing under the max reachback.
I could not throw a real nose down hyser until I started hinging under and not across. I started with practicing hysers with the hinged under pull back, (as will most likely result when you start as your hand will most likely be in the wrong position if you have been throwing with the arm reaching back across the shoulder joint). Now I can throw nearly every shot with my arm pull hard under and through, as a I have begun to couple my snap direction with the new plane. All of a sudden I can throw hard and stuff is not flipping, even into the wind. My finish is much more under and through, instead of across and around which, since my foot pivot is so poor has always slowed down my finish.
"The reasonable man adapts himself to his environment. The unreasonable man adapts his environment to himself, therefore all progress is made by unreasonable men."
-George Bernard Shaw