Interesting read
2. The Sweet Spot
Every batter knows that there is a special spot on a bat where the shot feels best. It sometimes feels so good that there is almost no sensation at all that the bat hit the ball. It's the same with a baseball bat or a tennis racquet or a golf club, so there is nothing special in this respect about cricket bats. Two special points on a bat are good candidates for the sweet spot. Technically, they are known as the fundamental vibration node and the centre of percussion. The node point is concerned with bat vibrations. Most impact points on a bat will cause the whole bat to vibrate, including the handle. Those vibrations persist well after the ball has left the bat, and they tell you whether you hit the ball cleanly. The biggest vibrations result when the ball strikes the tip of the bat. However, there is a spot about 150 mm from the tip where an impact causes no vibrations at all. That is the node point. As the impact point moves closer to the node point, bat vibrations get weaker and the shot feels nicer.
An impact near the tip of a bat will generate bad vibrations and it will also cause the handle to jerk forwards (towards the bowler), pulling your hand and arm with it. An impact higher up, near the handle, will push the handle backwards towards the body. In both cases there is a certain amount of jarring that feels unpleasant. The result is a sudden shock to the arm in one direction rather than a back and forth vibration. There is an impact point between the tip and the handle where there is no sudden motion of the handle at all. That point is called the centre of percussion. However, recent measurements show that it is too close to the handle to qualify as the sweet spot that batters talk about.