Getting stronger is like putting a bigger engine into your body. Strength is the starting point for almost all physical performance qualities. It can be defined as the ability to overcome external resistance by producing force or to oppose it through muscular effort. The stronger you are, the more potential you have to be faster, more powerful, quicker, etc. All you need to do is look at the equations for different qualities. For example, power is basically producing force rapidly (forcexvelocity), and the stronger you are, the more force you can produce. So, now that you know that you have to get stronger to perform better; lets look at another scenario.
Say the weaker athlete from above gets his squat up to 350lbs and went from a 20inch vertical jump (good measure of explosive strength) to a 30inch, and began performing better in competition. He then gets his squat up to 400lbs, but his vertical stalls as does his performance. In this case, he needs to work on developing his explosive strength and rate of force development. This way, he can use the new strength that he has to produce force faster; thus increasing performance.
All qualities of strength must be trained to develop optimal performance including max strength, speed strength, strength speed, explosive strength, etc. I'll discuss the different strength qualities in more detail in a future post.
Thus, if you are an athlete and you aren't already lifting weights and training outside of practice, you are really limiting your performance potential. Do you want to stick with your v4 or would you rather upgrade to a v8? Get to work!