If you want to be the best at your sport and perform to the highest level then you need to train specifically for your sport, developing the muscles and muscle actions for strength and power specific to your sport ! As well as training sports specific you also need a body that is in balance that performs in total coordination, all muscles moving synergistically for optimum  performance, so your sports specific training would also include muscle balance and postural work for optimum biomechanics ! When the body is performing in perfect unison all parameters of your sport will improve, speed , coordination, balance, stability ,excelleration!