The thing is though that F0 (max force), V0 (maximum velocity), Pmax (maximum power) and the SSC are all sort off distinct things, although they all matter and work together.
While the SSC will definitely help you use more energy and become more explosive, it's not the same as velocity necessarily. Velocity is based on contractile velocity, fiber types, rate coding firing (the speed and tempo in which your neurons fire to the muscles), inter and intra muscular coordination, and rate of force development to an extent. All these things are seperate from the SSC and would apply even if you don't have a stretch before the movement.
Btw, Power (Nm/s) = Force (netwon) * Velocity (m/s), but when applied to practical application it's not only power that's important but also the Force-Velocity prolife, ie, the relationship between maximum force and velocity. You can have high force and medium velocity and create a lot of power, and you can have high velocity and medium force and create the same power, but the balance between the two influences how explosive you are during a given task. It's not just how much power you can generate. There is some interesting stuff by Somazina et al. on the subject (
1,
2,
3), but this recent one from Reyes et al. with various interventions based on the force-velocity profiling (relationship) of the athlete, and squat jump outcomes, is very interesting (
4). It also matters where the task you want to perform is on the Force-Velocity curve and if there's any external resistance or not. It's a bit complicated to explain without going through it from the top.
I don't think there's evidence to say that it's easier to improve strength and maintain velocity, but not improve the SSC and velocity while maintaining strength. There's pretty sufficient evidence that all of it can be trained, strength training however takes longer past the initial neurological adaptions. I know what you're saying though that pure speed can be harder to improve for some.
He doesn't:
I must admit it triggers me a little bit that you guys can't see the difference, but I guess that's hard from the outside. He also changed the thread title and edited his OP based on my corrections.
See this is a perfect example of him not knowing what's he talking about. He is asked to provide evidence that you can train the SSC (which you can) and improve power and velocity (which you can). He then post a study from 2004 in which they measured the effect of ballistic training on MECHANICAL EFFICIENCY as the main focus, which while interesting doesn't pertain to the core of his argument. It's simply something he quickly googled and put in there.
Then he post a study from 1981 (lol) in which researchers showed that a greater prestretch potentiation led to a greater outcome, in this case a higher vertical jump. There was not an intervention, ie. no training program, meaning it has nothing to do with how you can IMPROVE it through training, which was what he was asked. It's just a random study on the subject.
He is a troll. I'll preempt his bullshit reply with that I don't care about his trolling.