For the players to direct the forces efficiently created by the kinetic chain, they should be aware of their body’s center of mass. Movement around the center of the mass is the most time efficient as weight is equally distributed between the feet creating a feeling of readiness to move in any direction, speeding up the time of the reaction and positioning. Transferring the weight and shifting the center of the mass gives the power to the stroke (and control) and therefore inputting this concept to the game can create drastic change in adding the power to the strokes while lowering the energy expenditure. Sounds good?
So if all of us are aware of the importance of the center of mass, how come that not a lot of us can use it in the most efficient way? 
The efficiency is the result of the player’s thoughts and how do the players perceive the situation, opponent, incoming ball and environment in general.
The center of the mass of the body is directly connected with the centering of the mind of the athlete. As centering of the mind makes the athlete more grounded, calm and relaxed, it lowers the levels of anxiety. 
Centering the thoughts, the athlete can be fully aware and controlling the body’s position and to be exact – it’s center of mass and energy transfer using the kinetic chain.
When the player is having defensive (and negative) thoughts, the center of mass is moving backwards. The negative thoughts are reflected through hesitation and backing off the ball. The weight is transferred backwards onto the whole foot (heels) automatically taking away the pressure of the toes pushing against the ground. Not only that in this way the weight is moving backwards before the stroke but during the stroke the player tends to straighten up and move the body upwards. Kinetic chain is efficient if the player transfers the energy from the ground (toes) to the hand wrist and grip pressure points, which should always be at the zone of the contact, IN FRONT OF THE BODY. If the player moves upwards, like in this case, the energy is transferred upwards (linear transfer without the angular transfer forwards) so the player hits the ball only using arm power.
Typical example in tennis is creating a spin. When I ask my players to hold the rally using spin they usually try to hit the balls most often from the the open stance transferring their center of the mass to the back of the foot. The explanation is that they consider spin as the defensive stroke (or a safe stroke) applying minimum power (minimum angle rotation forwards) and maximum spin (upwards). These thoughts of safety (neutral to defensive) lead to the shifting the body weight backwards and hitting the ball from the open stance.
If the player feels pressured and eager to rush into the stroke (high level of tension or confusion due to lacking of centering the mind), then the center of the mass is transferred forward too soon. The player leans forward too fast, not having in mind the pace of the ball and the pace of the body’s transfer of energy to the ball. The energy is transferred forward but usually missing the impact zone. The players can find themselves transferring all the energy at the wrong pace resulting in the wrong momentum of the stroke (too early or too late).
Typical example in tennis is a serve. It happens that my players sometimes pinpointing transfer too much energy off the center of mass forward to the front foot. Following their usual pace of the toss and stroke, in this case they miss a proper push of the ground upwards as their body is already leaning forward extensively. In this case, they land to the whole foot falling downwards to strong hitting the ball with the top side of their frame. The explanation is that they are too rushed to hit the first serve fast and strong so they stop being aware of the pace between the toss and their motion.
Play Smart Tennis - MIND YOUR GAME 