We are likely sideswiping the OP thread with regards to long toss debate, however I will add one more post regarding it.
If we can establish some points everyone can agree on, maybe my stance on long toss will make more sense. This is my opinion.
1. High velocity pitching is not a function of arm strength, it is a misnomer that building arm strength is critical in throwing a baseball. Yes, you have to have a minimum amount of functional arm strength, however the arm is not where velocity comes from. Similar to hitting, for the most part, the arms are just along for the ride. Creating bat speed, or arm whip is primarily a function of the body sequencing the legs, hips, core, and shoulders. In throwing a baseball hard, it is the body “delivering” the arm into ball release.
2. In order to maximize arm whip, the body (legs, hips, core, shoulders) are required to sequence in near perfect timing, to create elastic energy (stretch…in this case hip to shoulder separation), which in the end is converted / transferred into ball release.
If we are in agreement with most of the two points above, then it would seem to me that throwing a baseball at maximum distance, is a rather inefficient way of developing the “full body” strength, as well as sequencing, to maximize those attributes. Sure, I will admit, you will gain some added strength to the body parts listed above by long tossing, however every time you throw the baseball, you are adding the stress on the shoulder & elbow that occurs every time a baseball is thrown. You can maximize, and work those same body parts in explosive exercises to gain the exact same goal, without the added stress of the arm laying back at horizontal, and slamming with each extreme throw. You can hit all the buckets of baseballs you want without the risk of injury (for the most part), however that is not the case for pitchers. There is a very fragile ligament that is located in the elbow, of which is not very fond of the overhead throwing motion.
You absolutely have to throw a baseball (I am not saying don't throw) - flat ground, bull pens, some throwing drills are good, however I don't believe in a structured, maximum distance throwing program, nor do I believe the perceived benefits. Med ball slams, core work, plyo-metric training, weight training, and yoga all work the body parts needed to pitch safely, and with maximum velocity.
I do not believe arm strength (in the context most people use that term) is required or needed to throw a baseball safely. When pitchers get fatigued on the mound, it is not because only their arm was tired, in fact legs, and core go first, which then affects the stress placed on the arm.