user4 wrote:No, it will be the running surfaces and boards that will lead to the greater improvements in jumping distance just as they have had a significant role in the 100 WR time.
And sand! Don't forget sand!
Seriously, running surfaces and boards aren't going to contribute much more. Running surfaces have a standard of how much force they can return, and I don't know about boards but would assume the same thing. It's called a board because, when I was in school, it was made of wood. Now it's probably something similar, but it's not rubber and not spring loaded.