>>>,Could someone explain the concept of "a rearward force as the bottom-hand is being pulled forward." I get the idea that the the bottom hand pulls forward, but not sure that rearward force refers to pushing the bat. <<<
In regards to the top-hand, it should not be “pushing the bat” forward as the swing is being initiated. In the high level swings we saw in the derby, it was the pulling rearward of the top-hand and the rotation of the forearm as the elbow lowered to the side that accelerates the bat-head back toward the catcher from its launch position. – Below are a couple posts from the Archives that explain this further.
Rearward acceleration - Key to high level swing
Envision the whole path of the bat-head