Address Positioning

Just like we might start evaluating a golf swing in person or on 2D video, we often start evaluating a player in 3D by scanning through his or her positions at address. The address position can be thought of as the point in time one frame prior to any movement that starts the backswing. Unlike in 2D, within 3D we are able to quantify all of these positions. We can look at the values of an individual swing and also look at the relative consistencies between swings.

Let's review some of the address position variables we commonly evaluate:

• Stance Width: The distance between lead foot and trail foot.
  Because many instructors visually evaluate stance width as it relates to shoulder width, we can also quantify Stance Width as a percent of Shoulder Width.
• Stance Depth: The distance between the ball and a perpendicular line connecting the feet, or simply, how far out in front of the player the ball is from the feet.
• Ball Position: Another very common address position to evaluate visually. In the case of 3D we can evaluate this by measuring the distance between the lead foot and a parallel line projected from the location of the ball.

With the above variables, there are several factors (e.g. club used, intended shot, physical abilities, etc.) that can contribute to a very wide range of possible setup positions. Therefore, we aren’t always looking for the player to be within a particular range.  Often times we are more interested to see if the player is consistent in his or her set up. Especially when looking at ball position, the mean and standard deviation can quickly be used to find out if a golfer has consistent set up.  Often times, these can be difficult to see in 2D video and are often overlooked.