A stack and tilt golf swing is a modern concept of how to move your body and golf club to strike the golf ball and it is different from the more traditional method in six key ways.
At set up, a stack and tilt swing sees you placing 55% of your weight on your left side (for right handed golfers). As you make your backswing this then actually increases to 60% when you are at the top of your backswing and then increases again to 75-80% of weight on your lead leg at impact and then 95% on your follow through. This is done to allow you to keep your head totally over the ball during a stack and tilt golf swing.
As you initiate your backswing, with your weight increasing on your left side, your left shoulder will now make a downward action as it turns, rather than an inward rotation. This action helps you to maintain your head height during your backswing and maintains the centredness of your shoulder turn.
Your hands follow more of an arc on your backswing, rather than moving straight back parallel to the target line and your hands do not move opposite your chest as you swing back, they move opposite the lower area of your right bicep, so they are more on the inside than is traditional.
Your right knee actually begins in a flexed set up position but during a stack and tilt golf swing it straightens on the backswing rather than maintaining a flexed position. During your downswing, your right leg does flex once again and through impact both of your arms straighten and extend down the target line as you strike through the ball.
As you swing into your finish position in a stack and tilt swing, your hips tuck under your body so that your belt finishes in a higher position than it started.
So there are six key components of a stack and tilt golf swing that are very different to a more traditional method of swinging a golf club. Neither method is right or wrong so take some advice from your local PGA golf professional as to which style will suit you most.