Rate of Force Development is a timed measurement. It is a measure of how long it takes for maximal force of a muscular contraction to occur. Imagine yourself across from someone that has the same strength as you. The goal is to be the first one to push the other one backwards.
If you each have the same strength, who will win? The answer is the person who can generate the most force in the shortest time. This is one of the most sought after results with Acceleration. We want you stronger and we want you to be able to use your strength in the shortest time possible. That advantage will unlevel the field in your favor.