The Basics of the Golf Swing
Any golfer wanting to improve their game can do so usually by one of two methods or even both. One of which is through a series of lessons and then a lot of practice of what was taught to ingrain those movements until it becomes second nature. The other is complementing the equipment to fit the golfer’s natural swing and the tendencies. By no means is this book written as a means of understanding the golf swing and teaching the proper principles and techniques of teaching. There are enough books available by far better experts than I. Plus, there is a whole network of individuals who are qualified to provide instruction on a one-on-one basis. Instead, this book will concentrate on the latter - equipment.
The PGA (Professional Golfers’ Association) has dedicated pros that go through a regimented training program to teach the swing fundamentals. These pros are available at most golf courses and even some locations like driving ranges and retail operations that you may not have considered. There is one more organization called the USGTF (United States Golf Teachers Federation), in which their members also provide instruction.
I would sincerely hope that anyone that is providing lessons also has a thorough understanding of golf equipment or at least the desire to learn. For those that are interested in club fitting, I would equally encourage you to learn and understand as much as you can about the golf swing, especially cause and effect relationships. It is not a prerequisite to be one before the other or even both, but collectively knowledge can go a long way in diagnosing and then improving the efficiency of the golfer. After all that is why one enters these two disciplines; to help fellow golfers.
But there is one important issue I would like to state early on in this text and that is not to mix lessons with clubfitting. These are best done separately. Club fitting matches the components and dimensions to the tendencies the golfer may have. If a player is going through a swing change, it is almost counterproductive to fit that player until after you see what progress is made in the player’s swing. While golfers may have all the good intention of changing their swing, they may not commit themselves to practice and may eventually go back to what is natural, which was their previous swing. If the pro is teaching them to draw the ball and the golfer’s naturally swing is a slice, there is no set of club specifications that will satisfy both conditions.
Golf clubs can generally be altered later, but if you are building a set of clubs from scratch, you should have a solid understanding of ball flight principles as this can help suggest different clubhead designs or club specifications that can ultimately help you or your customer achieve their goal – lower their score and enhance the enjoyment of the game.
Terms you should know that impact ball flight.
These terms will help with reading and comprehending the remainder of the text.
Stance
According to the USGA in the Rules of Golf, the “stance” consists in a player placing his or her feet in position for and preparatory to making a stroke. This diagram shows the ball position relative to the clubs throughout the set. Normally the ball may be positioned a few inches inside the heel of the front foot regardless of which club is used. The only difference is who far the ball is away from the golfer, which is dictated primarily by the length of the club.
A narrow stance is when the feet are nearer to one another while a wide stance there is a greater distance between each foot. For shorter clubs like putters, wedges, and short irons the stance is narrow, but as the club becomes longer the stance becomes wider to achieve greater balance by establishing a solid foundation. Maintaining a consistent position helps to develop a repeatable swing.
Ball position
The ball’s position relative to the stance is important because it can dictate what direction the ball will go. Often a ball that is played too far forward or back in the stance may influence your angle of attack and the position of the face at impact, all of which affects distance and control. There are certain types of clubhead parameters that may work in unison or compound a particular problem. We shall see this when we discuss the geometry of the clubhead.
Alignment
One of the fundamentals of the swing is the stance or how you are aligned to the ball relative to the target line. There are three different stances and each one can influence the swing path and ultimately the direction of the ball. The first is the easiest to understand and it is called a square stance or where the shoulders, feet and hips are parallel to your target. A square stance will encourage a square impact.
An open stance is where the front foot is dropped back away from the target line, so the shoulders, feet and hips are open to the target line. This type of stance encourages a swing path that comes from the outside to in. Finally, a closed stance is where the back foot is dropped back slightly away from the target line, so the shoulders, feet and hips are closed from the target line. The difference in terminology between a square and open stance is often misleading, so examine the diagram to gain a better image between the two stances. For left-handed golfers, it would be a mirror image.
Swing Path
Stance is important from the initial part of the swing – the set up. The stance can encourage a specific type swing path, but a golfer can manipulate the swing path with how the upper body twists in relationship to the hips. This game is hard enough without trying to understand all the sequences from the takeaway to impact. A good friend of mine summed up hitting the ball the best as he said, “Simply hit the back of the ball with the front of the face.” Well, it is slightly more complicated than that, but not far off. A straight shot occurs because the golfer hit the very back of the ball with the clubface square to the target. This is also described as a square swing path.
An outside/in swing path occurs when the golfer hits the outside half of the ball. Granted it is not that far off from the back of the ball in most cases, but since the ball is round, impact is made maybe a dimple or two to the outer side of the equator of the ball. A severe outside/in path may be 6 or 8 degrees. As a point of reference go look at a clock. The target line for a RH golfer is a line drawn from the 3 o’clock to 9 o’clock position (or the 15- and 45-minute marks). If a golfer struck the back side of the ball, they would have contacted the 15-minute mark. If contact was made at the 14-minute mark, this would represent the same angle into the ball as a 6° outside/in swing path.
An inside/out swing path is where impact is made on the inside half of the ball. In our clock example, a 6° inside/out path would be the equivalent of making impact at the 16-minute mark. You can see how it becomes easier to hit the inside of the ball with a closed stance just the same as being able to hit the outside half of the ball with an open stance.
Use a Compass to Guide You
A drawing compass is a drawing tool that can draw circles, or in our case arcs or incomplete circles. It consists of two legs joined at a hinge. One of the legs contains a sharp point used as a pivot point while the compass turns. On the other end is a pencil to mark the lines.
The swing path initiates around the pivot point or in this case the hub of the swing. It can be explained quite easily by using a drawing compass for our example. The shorter the two arms are apart the arc will have a tighter radius. This would be the same as a club that is shorter than another. The swing is never in a straight line as we rotate around our spine.
When we looked at the three different stances from a bird’s eye view, we could see how the direction of the clubhead can be influenced. The dotted line is square and perpendicular to the target.
Face Attitude
The other half of the equation on where the ball might go had to do with the position of the face of the club at impact or face attitude. This is not to be confused with the face angle of the head, but the position of the face of the club relative to the target line. This accounts for the rotation of the wrists, the clubhead around the shaft axis, the bending of the shaft, etc. Ultimately it is how the golfer brings the club back to the ball at impact and it may not necessarily be the same as it started out at address.
The face angle of the club at impact can either be square to the target, open (pointed right of the target for a right-handed golfer) or closed (pointed left of the target for a right-handed golfer). For left-handed golfers, the opposite will occur at impact.
Slices, Hooks, and other golf related terms explained
There are swing analysis tools that are used by club fitters that can accurately measure the exact face angle at impact along with how many degrees inside/out or outside/in the swing path is on any given swing. Because the clubface is traveling so fast, it is impossible to tell how many degrees the face may be open or closed or if any in the case that a square impact was made without such devices. However, it might be possible to know by understanding Ball Flight Patterns chart and accompanying diagrams.
The direction is initially dictated by the face angle at impact (@85%) plus any side spin (or a tilt of the spin axis according to some) controlled by the path of the swing. A square face results in no side spin. A closed face creates a draw spin component, while an open face creates a slice spin component. The best image can be found if you ever played ping pong and watched how the ball curved when cutting across the ball at different angles. Another important consideration is the harder the ball is hit at the same given loft the more spin will result. Also, the greater the difference between the swing path and the target line, the greater the spin rate (or tilt of the spin axis) will be as well.
As a recap, there are three swing paths (straight, inside-out, outside-in) that the club face can come into the ball, plus there are three different face angles (open, square closed) the club can be at impact relative to the target line. This combines to form 9 different ball flight pattern possibilities that can occur at impact.
The 9 Ball Fight Patterns |
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| Diagram | Swing Path | Face Angle | Probable Ball Flight Pattern |
Description | |
| A | Square | Square | Straight with no side spin | Straight | |
| B | Square | Open | Starts straight and goes right with slice spin | Fade | |
| C | Square | Closed | Starts straight and goes left with hook spin | Draw | |
| D | Outside/In | Square | Starts left with no side spin | Pull | |
| E | Outside/In | Open | Starts a little left, slice spin | Pull - slice | |
| F | Outside/In | Closed | Starts left with hook spin | Pull – hook | |
| G | Inside/Out | Square | Starts right with no side spin | Push | |
| H | Inside/Out | Open | Starts right with slice spin | Push – slice | |
| I | Inside/Out | Closed | Starts a little right, hook spin | Push - hook | |
We will go one by one over each of these, but the chart will show what happens when say the face is square, but we have an outside/in path. In this case it will result in a pull.
In certain cases, depending upon how open or closed the face angle is or the path could result in more severe situations than what is shown. The diagram below is an overlay of each of the scenarios where the path and/or face angle is no more than 2° to show you just how far offline the ball can go with such little variation.
Let’s look at a diagram of each of the 9 different possibilities individually to understand what can occur on a center shot. Each of the different scenarios are based on a 100 mph swing speed and the approximate position of the ball is where the ball lands on the fly without any roll. All the numbers on the grid represent yards and the gray shaded area is the width of an average fairway (32 yards wide).
Let’s start out with the easiest one and that is the straight shot. This is illustrated by Diagram 2A. Regardless of the speed of the golfer, the ball will land on this same line. However, this is a clinical approach as it is nearly impossible to hit the ball with a perfectly square face and a path that is perfectly square as well (not to mention wind conditions, terrain, etc.). By limiting the face angle and path to fractions of a degree from perfectly square, the result can still be considered a straight shot as the direction left or right of the target and any side spin will be minimal.
Diagram 2B shows an example of a Fade where the path may be square, but the face is open at impact. For a RH golfer, the ball starts straight and then turns to the right because of the slice spin. Even where the face is only 2° open, it is enough to miss an average fairway width to the right for a golfer with approximately 90 mph or more.
Diagram 2C is the opposite of the fade just discussed called the Draw. The hook spin comes from the closed face which results in the ball going to the left for a RH golfer. Again, as little margin as 2° can result in a missed fairway.
Diagram 2D starts the scenario in which the path comes from the outside/in. With a square face, the result is a Pull, basically a straight shot just going in the wrong direction. Because the path of the face is square, no side spin is incurred to further influence the ball flight. Up to 4° outside/in may keep the ball in the fairway for most golfers.
Diagram 2E represents a Pull-slice ball flight. This occurs when the path is outside/in, but the face angle is open. For a RH golfer, the ball goes from left to right. In some cases, a fade is good and ends up at the intended target and in other cases can completely miss a fairway or green depending upon how many degrees outside/in the path is and more importantly, the relationship to how open the face is. New ball flight laws suggest the ball starts off at approximately 85% in the direction the clubface at impact. Plus, the higher the player’s clubhead speed, the more pronounced the effect is. For more skilled golfers, they intentionally fade the ball to “work” it around a particular hazard or shape the shot to a specific position on the green. The caption below the diagram shows three different scenarios and underscores the difference in the different types of pull-slices.
Diagram 2F illustrates a Pull-Hook ball flight where that path is outside/in and with a closed face. When severe, this is commonly called a “duck hook.” Rarely will a pull-hook stay in a normal sized fairway or on a green except for those with very slow swing speeds.
Diagram 2G is the first to illustrate the different scenarios when an inside/out swing path is present. In this case the face is square resulting into a Push. Again, this is a straight shot just going in the wrong direction. Because the path is face is square, no side spin is incurred to further influence the ball flight. Up to 4° outside/in may keep the ball in the fairway for most golfers.
Diagram 2H shows the dreaded Push-Slice. This occurs when the path is inside to out causing the push part. In addition, the open face creates slice spin making the ball go even further to the right for a RH golfer. This is the opposite of the pull-hook, but the result is the same; the ball rarely remains in the fairway or on the green. The difference between a slice and a fade is the swing path, even though both are hit with open faces. In these cases, if the face is severely open it can result in the ball going into an adjacent fairway or beyond. But in the pull-slice, the golfer aims left by opening the stance and hitting the outside of the ball or closed face and the ball fades or slices back.
Our last diagram 2I shows what occurs when the path is inside/out, and the face is closed. For a RH golfer, the ball starts left or slightly right and curves back left which is also known as a push-hook.
Where the ball lands are the relationship between how many degrees inside/out the path plus the number of degrees the face is closed. Again, new ball flight laws suggest the ball starts off at approximately 85% in the direction the clubface at impact. Plus, the player's swing speed and the club's loft affect the severity. When the swing speed is reduced or the loft increases (as in the case with higher lofted irons), the curvature is reduced.
For more skilled golfers, they intentionally draw the ball or “work” it around a particular hazard or shape the shot to a specific position on the green. The caption below the diagram shows three different scenarios and underscored the difference in the different types of draws: push-hook or a pull-hook.
These are the 9 different situations that can occur on center shots with the three-swing path and face angle possibilities each. Be aware that ball flight can be more complex than this when you factor in the further possibilities of hitting out toward the toe or heel or high or low on the clubface. But we will leave that for later in the book when we discuss bulge and roll and what happens on off-center shots.
Angle of Attack (Ball off the ground)
Angle of attack (or also approach) is a term used to describe the swing plane of a golfer and is dependent upon the position of the ball relative to the arc of the clubface. A level swing or zero angle of attack might be the easiest to show and understand. A level swing is where impact is made at the very bottom of the swing arc. Some golfers might recognize this as a sweeping swing or the term picker.
In golf, any time the ball is to be hit off the ground, it is usually recommended to “hit down” on the ball slightly for solidness of contact and to impart back spin. This creates a descending angle of attack. There are several ways a descending angle of attack can occur. One is simply moving the ball back further in your stance, while another might be caused by a forward weight shift or a forward hand press or shaft lean. We will not get into the how’s and why’s here and leave that for the instructors. Rather, we will discuss the importance of clubhead design because of the angle of attack. An angle of attack that is steep at impact will result in more turf being taken AFTER impact with the ball. You want to avoid situations where a divot is taken before impact as this reduced clubhead momentum and potential distance.
An ascending angle of attack is an upward swing into the ball. The only time this should occur is if the ball is elevated off the ground, such as on a tee or the ball sitting high up in fluffy grass. A ball that is positioned further forward in the stance will result into an ascending angle of attack. In the diagram above, two different angles of attack positions are illustrated (ascending not included).
Many beginning and lady golfers tend to have more of a sweeping or level angle of attack (top view) as opposed to lower handicap players who tend to hit their irons and wedges at a slight ascending blow (bottom view). This is more of a generality as there are high handicappers who will hit downward on the ball (perhaps too downwardly) or some better golfers who might have a level swing. So, base it on a case-by-case basis. But due to these different types of swings the equipment should complement it.
There are several things to take away from these two diagrams. Note that the face will be slightly behind the ball that is sitting atop the grass. The head shaded in gray is the club at address. The head in the lighter shade of gray is the position at impact. The white line is the boundary between the grass and the Earth so you can see where the club makes contact.
The level angle of attack does not contact the ground or create a divot, although may look like a bruised mark along the grass where the ball sat after impact. In contrast, the 5º angle of attack might take as much as a 4” divot (again, after impact). A shorter divot would have meant a positive or shallower angle of attack, while a longer length divot would have indicated a steeper angle of attack.
The other interesting point to take away from these diagrams is the position the ball makes impact with the face. Assuming the ball is resting the same distance from the ground, the shallower angle of attack will be struck lower on the face than the steeper angle of attack. This will be important when we discuss clubhead design parameters that will complement each type of swing.
Lastly, the trajectory of the ball as it leaves the clubface (launch angle) will be controlled by several factors. These are:
Dynamic loft at impact
This is the angle of the face at the precise moment impact is made and not the loft of the club listed in the specifications by the manufacturer. The angle of attack factors into the equation. As you can expect, the lower the loft at impact, the less oblique the collision will be allowing a greater amount ball velocity as the ball is compressed more.
Friction
This is the force between the ball and the clubface. The smoother the surfaces are the less friction is created, while rougher surfaces create more friction. This is why you find grooves on the face and dimples on the ball to provide enough friction to reduce the golf ball from sliding (or deforming) up the club face. When grass, water and dirt come between the ball and the face, this reduces friction and spin. This is why it is difficult to spin the ball out of tall grass.
Ball impact location
Depending on which side the ball makes contact in relationship to the club head’s center of gravity will influence the angle it leaves the face. A lower impact results in a lower ball flight than one at or above the center of gravity. Impact location will also factor into the spin of the ball as you will see when we discuss gear effect later in the text.
Speed at impact
The last parameter that determines the launch angle of the ball during the flight is the speed. Greater speed will impart more spin on the ball than a slower speed with all else equal.
Angle of Approach (Ball off the tee)
An angle of approach should occur if the ball is elevated off of the ground, such as on a tee or the ball sitting high up in fluffy grass or if the ball is positioned on an incline forward of the center of your stance. For this reason, I like the term angle of approach better in this situation. The driver is almost exclusively teed up when in use, therefore deciding on the proper loft driver is very important to obtain the most distance possible with your strength and ability. To explain why, we will use some illustrations as examples of what can happen.
Since we are not robots, each golfer will have a slight change in their angle of approach (or attack) to the ball. Part of the reason is that when we address the ball, we may stand slightly further away or closer to the ball and the ball may be more forward or back in the stance. When you factor in the ball will be teed at different heights because of the human effort of placing the tee in the ground of various firmness, you can appreciate or understand why we don’t always hit the ball the same height or direction each time. Therefore, fitting is based many times on tendencies more so than any absolutes.
Unlike an iron where most low handicapped golfers will tend to hit down or on a descending angle of attack, the same cannot be said of hitting off the tee. There are some of the best players in the world that can hit the ball with a descending angle of attack rather than hit the ball on the upswing.
We will show why this is important when we start discussing some of the clubhead parameters, especially loft. I bring this to your attentions because of the increasing access and availability to launch monitors at numerous shops across the country, golfers are better able to see more accurately (with quantitative data) why a particular loft might be better suited to their swing. For golfers with abnormally high or low trajectories this may very well be caused by less than a perfect swing, but we will see how to fine-tune the club to improve efficiency.
Swing Plane
One other factor the club fitter should know about is the swing plane or the angle at which the club is swung. The swing plane is often described as the imaginary plane on which the clubhead travels during the golf swing.
In the diagram you see two solid lines depicting the plane at which the club is swung. The blue line is another plane that the club could be swung and described as flatter or less vertical.
Not in all cases, but taller players will often have a more upright plane than a shorter player. A longer club will also create a flatter swing plane than a shorter club, which will be explained more in detail when we start discussing the lie in clubhead design.
The reason why this subject is brought up has to do with the height a player may hit the ball. Imagine tossing a ball underhand toward a target. Now toss a ball at the same target, but this time use more of a side armed motion. The side armed motion is an example of a flatter plane and what you will notice is the ball leaving the hand at a lower launch angle. If you happen to have a taller player with an upright swing plane, their natural tendency will be to hit the ball higher regardless of what you might give that player, as this is a function of the swing.
Observe wear patterns on the golf club!
Take the opportunity to examine a player’s clubs if they bring them with them to a fitting. In the picture you can see the bottom sole of a golf club. If you look carefully, there are lots of clues to how this person swings the club. Over time, you will start to see brush marks from repeated impact with the ground or driving range mats. It may be hard to see, but most of these brush marks go in the direction from heel to toe. If the face angle was square, then you would see the brush marks perpendicular to the face.
See the white tee mark left on the sole? I guarantee that was a slice as the face would have been severely open to produce that mark.
Look at the diagram on the right for a second. Even though an iron is shown, it could be any type of club. If the brush marks are going from heel to toe that would indicate this person has an open face at impact. If the brush were primarily going from toe to heel, that would indicate a closed face at impact. Usually the amount is minimal, like 5 degrees or less, but a certain pattern will exist.
Do not forget to look at the impact on the face too. Are they clustered or all over? If they are clustered, are they consistent out near the toe, heel or low on the face? If so, certain parameters will help rectify those tendencies.
Examining wear patterns or marks on the club can tell you a lot if you are observant. What we have gone over in this chapter are just some of the things you will need to know as why a golfer might hit the ball a particular way and help you decide what club fitting variables will help improve or complement those tendencies. It never hurts to hit balls at the range with a more open or closed stance or tee the ball further back, forward, up, or down than you normally do just to witness where a ball is likely to travel. Remember to take notes so you have something to reference.
