ok, so you think that you're on the same level as them, have a routine as complex as they do and have the same level of physical ability as these elite athletes? You don't need my advice then, and you certainly don't need to be farting around here trying to convince one person of the benefits of this training.
I'm not a coach of elite athletes, nor to I profess to be one. But for 99% of the people here who are NOT elite athletes, and do NOT compete at high levels of their sport, and DON'T have all the time in the world to train, and CANNOT fit shit like that into their routine because they have to spend more time on shit that gets them 90% of the way there without ever having to worry about spending twice as much time working at that extra ten percent.
My guess is that they probably use that shit in a way that you could chalk up to gpp, while devoting at least twice as much time within the same cycle to maintaining technique (not working on performance) in their sport. There's a big difference to that and how most people will apply these methods, and it has to do with the amount of time you can afford to put into training. Most fighters (and ESPECIALLY people on here) would be better off hitting the bag harder than worrying striking with resistance.
lastly, under and overspeed pitching would be ok I think. unless they're using shotputs or something. But I don't profess to know everything about baseball (least of all pitching) so I'd have to learn more before ever reccomending that to anybody.