Bat Speed Potential
Achieving the first 70% of your potential is relatively easy. Many roads and types of training will get you there. However, achieving the last 30% is very difficult and only one road will get you there.
No matter what the current ability level is, a hitter can always improve. Most don't truly push themselves. The improvement potential is a lot larger than most parents and coaches think.
The key variable is the intensity of the player.
One of the main goals of bat speed training is to achieve 100% recruitment of fast-twitch muscle fibers. The human body always tries to use the least amount of energy when performing any muscular movement. It starts by recruiting the slow muscles first. These burn the least amount of energy. Only when forced to be explosive does the body tap into the fast-twitch muscle fibers. Even then it will only use the smallest number necessary.
Also, the body uses the most familiar neural pathways to activate muscle fibers. This leads to the same muscle fibers used each time unless you create an extraordinary condition. One way to achieve this in an athlete is to fatigue the normally used fibers and force the reserves to activate. In order to do so, the athlete must train on the edge of their ability level.
This is the same principle used in strength training. Maximum strength and power occurs when you train to failure with weights greater than 70% of your maximum voluntary contraction. You can also train with lighter weights (ballistic training). Going to a state of failure also appears to be the fastest way to increase muscle size and density. This produces muscle strength.