But, a heavy ball puts too much stress on the equipment. Most of our strengths today were our weaknesses yesterday. Focus and concentrate on every thing you do. If you don't you're wasting time. Learning how to practice is a key factor in becoming competent at any thing you do.
Improvement is rapid once a player learns how to practice.
Much effort has been taken to explain the various theories - i.e. contact surface of the bat, contact zone, extension, part of the ball that's being hit etc. Have a clear idea. You must adjust by making your shot longer. Same in hitting. Make the proper adjustments to succeed.