Can a Tee Make a Difference?

Earlier in the year at the PGA Merchandise Show in Orlando there was quite a few companies displaying tees promising extra distance and better dispersion. I picked up a selection of the tees just to see how effective they might be.

Here's a selection of some of the tees. In order to test the tees I kept a few of the variables constant. I used the same golf ball, Titleist Pro V1 2011 version, for all shots. Used the same driver Titleist 913 D3 9.5 degrees of loft and a Graphite Design Tour AD Di-7 S-Flex 45 inch shaft and kept the tee height constant with all shots.

The shots were hit on the evening of the 9th of June with little wind and a temperature of around 19 degrees celsius. Excellent conditions for testing.

All shots were recorded using the Trackman 111 launch monitor. I hit 12 drives with each, the reason being balls are normally sold by the dozen and in a standard round of golf you might expect to hit 12 drives, taking away 4 par 3's and a couple of holes where a fairway wood might be used.

The Trackman figures that are of interest are Club Head Speed, Ball Speed, Spin Rate, Launch Angle, Carry, Total Distance and distance from target. An average was taken of the parameters and compared to see if there would be a difference between the various tees.

Testing

The first tee tested was the traditional 2 3/4 inch wooden tee. It would be also used as the control to compare the tees to.

Tee	Club Speed (mph)	Ball Speed (mph)	Launch Angle	Spin Rate (rpm)	Carry (yards)	Total Distance (yards)	Lateral Distance from Target (feet)
Wooden	103.1	152.4	11.8	2332	243.7	269.7	25.95

The second tee tested was the Epoch tee by Evolve Golf. www.evolvegolf.com

From the website.

'The Epoch is the only performance tee with radius posts that span the width of a golf ball dimple. This unique feature creates the lowest coefficient of friction of any tee, eliminating deflection at impact and increasing ball speed and control off the tee.'

Tee	Club Speed (mph)	Ball Speed (mph)	Launch Angle	Spin Rate (rpm)	Carry (yards)	Total Distance (yards)	Lateral Distance to Target (feet)
Epoch	103.4	151.1	11.7	2421	242.9	267.7	25.58

The third tee was the Zarma Fly Tee Pro from Champ. http://champspikes.com/products/golf/accessories/fly-tees/zarma-flyteepro/

From the website

'The new CHAMP FLYteePro is a well-engineered high performance golf tee with a soft shock absorbing color tip on a low friction 6 prong head. With exceptional distance and accuracy golfers of any caliber will see improvement in their game. Designed with a virtually indestructible polymer this is the last golf tee you will ever need.'

Tee	Club Speed (mph)	Ball Speed (mph)	Launch Angle	Spin Rate (rpm)	Carry (yards)	Total Distance (yards)	Lateral Distance to Target (feet)
Fly Tee	103.4	152.4	11.3	2337	245.7	273.7	16.16

The fourth tee was the Totem Tee, www.totemtee.com

From the website

Totem Tees offer the following benefits:

• Legendary distance due to significantly reduced spin rate
• Unparalleled accuracy as a result of a tighter dispersion pattern...even in strong winds
• Less club head deflection
• More accurate ball strike
• Promotes a better angle of attack
• 
  
   
  
  

Tee	Club Speed (mph)	Ball Speed (mph)	Launch Angle	Spin Rate (rpm)	Carry (yards)	Total Distance (yards)	Lateral Distance to Target (feet)
Totem	102.7	152.2	11.7	2375	246.3	272.5	22.47

The fifth tee was the Firecracker Tee from Kiwi Golf. kiwigolf.com

From the website

'Straighter and Longer with maximum smash factor.'

Tee	Club Speed (mph)	Ball Speed (mph)	Launch Angle	Spin Rate (rpm)	Carry (yards)	Total Distance (yards)	Lateral Distance to Target (feet)
Firecracker	103.3	153.1	11.4	2499	248	273.7	30.04

The sixth and final tee in this test was the Flex Head Tee, http://www.flex-head.com/

From the Website

'Consistent Heights, Flexible, Unbreakable for Life.'

Tee	Club Speed (mph)	Ball Speed (mph)	Launch Angle	Spin Rate (rpm)	Carry (yards)	Total Distance (yards)	Lateral Distance to Target (feet)
Flex Head	103.1	153.2	11.2	2570	247.2	272.2	36.74

Collated Results

 

Tee	Club Speed (mph)	Ball Speed (mph)	Launch Angle	Spin Rate (rpm)	Carry (yards)	Total Distance (yards)	Lateral Distance to Target (feet)
Wooden	103.1	152.4	11.8	2332	243.7	269.7	25.95
Fly Tee	103.4	152.4	11.3	2337	245.7	273.7	16.16
Firecracker	103.3	153.1	11.4	2499	248	273.7	30.04
Totem	102.7	152.2	11.7	2375	246.3	272.5	22.47
Flex Head	103.1	153.2	11.2	2570	247.2	272.2	36.74
Epoch	103.4	151.1	11.7	2421	242.9	267.7	25.58

With the results collated into one table above we can compare easily. The club head speeds are very consistent with only a variance of 0.68% between the top speed and bottom speed, this would give an indication that a similar swing was put on all the shots.

The tees do give a slight variance in results.

The Fly Tee and the Firecracker were the longest, giving a total distance of 273.7 yards, 6 yards longer than the Epoch. The Firecracker gave the longest carry of 248 yards, 5.1 yards longer than the Epoch.

The highest ball speed came from the Flex Head tee 153.2 mph, 2.1 mph faster than the Epoch.

The lowest spinning tee was the traditional wooden tee with 2332 rpms, 238 rpms less than the Flex Head.

The Fly Tee had the best dispersion averaging only 16.16 feet from the target line and 20.58 feet closer to the target than the Flex Head.

Conclusion

The question which needs to be asked is how much of the differences in results are down to the tees and how much are down to the striking of the player? You might surmise that hitting 12 shots with each driver would deliver a consistency to the results but with a small sample size this mightn't be the case.

Also the last tee tested was the Flex Head which had the worst dispersion results, this could be attributed to the test subject tiring, having had hit close to 100 drives at over 100mph at that stage.

One of the advantages of the Epoch, Fly Tee, Flex Head tees are their durability, lasting much longer than the wooden and Totem tees. The Firecracker didn't seem to that durable at the start with a couple breaking easily but the third tee lasted easily for the rest of the test.

The Firecracker Tee, which has the ball sitting in a nice cradle, seems to invite the player to launch the ball and did give the longest carry.

The best performing tee was the Zarma Fly Tee Pro with excellent distance results and even better dispersion results. Even with potential test inconsistencies isn't it worth trying a simple piece of equipment that would give a yard or two more distance and a yard or two more accuracy!!

Any questions or comments are always welcome.

Understanding Ball Flight - Why Did the Ball Go That Far?

The three questions that have been looked at to understand ball flight have been:

1. Why did the ball start there?
2. Why did the ball curve that way?
3. Why did the ball go that far?

The last two blog posts answered question 1 and 2. This post will answer question 3, why did the ball go that far?

There are several factors that effect distance that the golfer has no control of. These include wind, temperature, humidity, altitude, moisture, ground conditions etc.

There are equipment factors that influence distance which include golf ball design (materials, dimple design etc.) and golf club design (head, shaft, length, weight etc.)

The three factors that influence distance which a golfer can control are

1. Spin Rate
2. Launch Angle
3. Ball Speed

Long distance comes from high ball speed, a high launch angle and a low spin rate. These factors can be changed by altering swing mechanics. Let's take a closer look at the factors.

Spin Rate

The main factors that will affect the spin rate are

1. Dynamic Loft
2. Attack Angle
3. Club Speed
4. Impact Position
5. Friction between ball and club face

The factors all influence each other and it's the combined effect of all five that result in the total spin of the ball. The ball spins backwards through the air, backspin is a good thing and like all good things too much or too little can be bad!! There is an ideal range of backspin for each club, it is higher for wedges and lower for drivers. Players with lower swing speeds need higher spin rates to keep the ball in the air longer. Players with higher swing speeds require less spin.

Dynamic Loft

Dynamic loft is the vertical club face orientation at the center point of contact between the ball and club face at the maximum compression of the golf ball. This is basically the loft of the club at the impact point on the face. Due to vertical roll on the club face, a ball hit higher on the face has a higher dynamic loft, a ball hit lower on the face has a lower dynamic loft. In general the higher the dynamic loft the higher the spin rate.

Attack Angle

Attack angle is the vertical direction of the club head's center of gravity movement at maximum compression of the golf ball. A lower attack angle can create more spin and a higher attack angle can create less spin. However attack angle and dynamic loft together directly influence spin rate. This relationship is called spin loft.

Spin Loft 

Spin Loft is defined as the angle between the direction of the club head's center of gravity movement (attack angle and club path) and the club face orientation at the center point of contact between club and ball (dynamic loft and face angle) at the maximum compression of the golf ball. In essence it is the difference between dynamic loft and attack angle, but differences between path and face can influence it as well.

This picture from www.trackmangolf.com illustrates spin loft. In the two examples different dynamic lofts and attack angles produce the same spin loft and the same spin rate.

Spin Rate can be calculated from club head speed x spin loft x 2.3 (driver) or club head speed x spin loft x 2.6 (iron).

Impact Position

Impact position on the face impacts spin rates through vertical gear effect. With the club rotating around it's center of gravity, impacts above the center of gravity have reduced spin and below have increased spin.

Friction

The total amount of friction between the ball and the club face will effect spin. A good example would be the 'flier' i.e. when there is grass or moisture between between the ball and club friction is reduced and the ball 'jumps' or has less spin and travels further than expected..

Club Speed

Higher club speeds have greater potential to generate more spin.


Launch Angle 

For any given ball speed and spin rate there is a corresponding launch angle that will maximise distance. Launch Angle will always fall between dynamic loft and attack angle of the club. The dynamic loft has a greater influence. For drivers 85% and for irons 75% of the launch angle is accounted for by dynamic loft. If friction is reduced the dynamic loft can have an even greater influence.

 Here's a chart from http://www.planetruthgolf.com/PlayerResources/Forums/tabid/77/aft/28402/Default.aspx showing optimal launch parameters for maximum carry. Bear in mind that for maximum overall distance less carry and more roll may work better.

Ball Speed

The last factor that effects distance is ball speed. There is a relationship between club head speed and ball speed. The efficiency of speed transferred from the club to the ball is Smash Factor. If a player has 100mph club head speed and 150mph ball speed the smash factor is 1.5. The closer the smash factor is to 1.5 the better. The best way to increase ball speed is to improve center face contact.

For this reason shorter shafts in drivers may be better. Shorter clubs are easier to control and as a result easier to hit out of the center of the face. The very minute loss of club head speed is more than made up for in the more centered strike with a resultant increase in accuracy.


Summary

The three factors, Ball Speed, Launch Angle and Spin Rate, combined explain the distance any golf shot goes. Spin Rate is calculated by speed x spin loft x 2.3/2.6 (driver/iron). Launch angle is influenced by 85%/15% dynamic loft/attack angle for a driver and 75%/25% for an iron. Ball speed comes from club head speed with a centered contact.

A high ball speed, derived from a centered strike with high club head speed, with a high launch combined with a low spin rate will mean long distance with the driver. A golfer looking to maximise their driver distance should look to improve strike and then optimise their launch conditions and spin rate. Launch Monitors such as Trackman are great tools to find the numbers to optimise your driver distance. If you get a chance to use one, do, you might end up hitting drives you never dreamed of.

Other ways of increasing distance include playing in warm conditions, with the wind at your back, at altitude with dry firm fairways!!

As always comments and questions are appreciated.

Understanding Ball Flight - Why Did the Ball Curve That Way?

In order to understand ball flight there are three questions to ask.

1. Why did the ball start there?
2. Why did the ball curve that way?
3. Why did the ball go that far?

In the last blog post, the first question, why did the ball start there?, was answered, in this post the second question, why did the ball curve that way?, will be answered.

Of the five impact factors, clubhead speed, club path, club face angle, angle of attack and centeredness of strike the main ones that affect ball curvature are club path, face angle and centeredness of strike.

Spin Axis

What causes a ball to curve is a tilt in it's Axis of Rotation. The axis of rotation is the axis in which the ball is spinning around. The ball spins around one axis, sometimes people believe there is a combination of backspin and sidespin, but this doesn't happen.

 

The line going from left to right is the axis the ball is back spinning around. The axis is also tilted to the right in this photo meaning the ball will move from left to right in the air.

Imagining an airplane turning is a good way to see how a tilt in the axis of rotation will affect the flight. With the wings tilted to the right in this photo the plane is turning right. A ball with a tilt to the right will move from left to right and a tilt to the left will have the ball moving right to left.

Trackman figures show that for every 5 degrees of tilt in the spin axis the ball will curve approximately 3.5 yards to the side for every 100 yards of carry.

Spin Axis tilt is caused by a difference between club face angle and club path, Trackman names this difference as Face to Path. If the face is open to the path, the spin axis will tilt to the right and the ball will move left to right. If the face is closed to the path, the spin axis will tilt to the left and the ball will move right to left. 

Gear effect on clubs, mainly woods, also has a major influence on spin axis. Heel strikes tilt the spin axis to the right, resulting in left to right shots. Toe strikes tilt the spin axis the the left, resulting in right to left shots.

Influence of the D-Plane on Spin Axis Tilt

The D-Plane or Descriptive Plane was coined by Theo Jorgensen in his book 'The Physics of Golf'. The easiest way to describe D-Plane is it is the plane that contains the initial flight of a golf ball after impact with the club face. The D-Plane is created by the club path and the club face orientation at impact.

This picture from www.brianmanzella.com is a good illustration of the D-Plane. The face is closed to the path, causing the spin axis to tilt to the left, the ball will move from right to left and initial starting point is closer to the clubface than the club path.

Gear Effect

Earlier on it was mentioned that the strike point on the face would affect the spin axis. This is due to Gear Effect. A golf club will rotate around it's center of gravity. A golf ball that impacts on the face in line with the center of gravity will have not have any face rotation due to the contact collision. Is the ball strikes more towards the toe the club face rotates open and vice versa for a heel strike.

Gear effect is the counter rotation inflicted on the golf ball due to the interaction of the rotating face on the golf ball. A toe strike causes the spin axis to tilt to the left and a right to left ball flight. A heel strike causes the spin axis to tilt to the right and a left to right ball flight.

For irons the center of gravity is close the the club face and irons exhibit minimal gear effect. With woods the center of gravity is quite far from the face and woods exhibit significant gear effect.

For a driver Trackman indicates that an impact that is 0.5 inch from the center will impart 20 degrees of spin axis tilt. This is quite a large number and is a major factor in ball flight. It can override the influence of the D-Plane at times.

Here is a photo from www.tutleman.com illustrating gear effect.

Face Closure Rate

One other factor that effects curvature is the rate of closure of the clubface through impact. If the face is closing around a point behind the face it will impact the spin axis like heel contact gear effect.

Summary

The factors that determine curvature of the ball are the difference between the club path and club face orientation at impact. The D-Plane illustrates this. Gear effect also has a big impact on spin axis and how the ball curves. The least known factor is the face closure rate, a the face is closing around a point behind the face it will impact the spin axis like heel contact gear effect.

As a result the main way to hit a straight golf shot is to have a centered strike with little face closure combined with a club path and face angle that are pointing in the same direction at impact. A straight shot can also be obtained when a non centered strike counteracts a face to path difference.




Any questions and comments are always welcome.

Understanding Ball Flight: Why did the ball start there?

If we are looking to become better golfers, a better ball flight helps. If we understand what is causing a ball flight we can make improvements.

The three questions we can ask about ball flight are:

1. Why did the ball start there?
2. Why did the ball curve that way?
3. Why did the ball go that far?

If we know the answers to these questions, we can start to make changes and improvements.

In this blog post we will look at the first question. Why did the ball start there?

Where the ball starts is called Launch Direction. Launch Direction is defined by Trackman as the horizontal direction of the movement of the golf ball's center of gravity immediately after leaving the club face.

There are five impact factors, club face angle, club path, angle of attack, club head speed and centeredness of strike. The main ones that affect launch direction are club path and club face angle.

Club Path versus Club Face Angle?

Club Face Angle has a much greater effect on launch direction than Club Path. An easy was to illustrate this is to hit a 20 yard chip with a 5 iron. First hit the chip to a target and watch where it starts and goes, then with a second shot aim the 5 iron face at a 45 degree angle to the left. Hit the chip shot with the same swing (keeping a similar path) as the first one, the ball will start a long way left, close to the 45 degree angle the club face was pointing, showing cub face angle has a much greater effect than club path.

Club face angle accounts for approximately 85% of the launch direction for drivers and 75% for irons. Let's use an example to see what launch direction a club face angle and club path might produce for a 5 iron.

For a club path of -6 degrees (minus values indicate to the left of the target, positive to the right) and a club face angle of 4 degrees the ball will start ((-6x0.25= -1.5) + (4x0.75 = 3) = 1.5), so with this path and face angle the ball will start 1.5 degrees to the right. Even though the path has a greater value, the face will have a greater influence on where the ball starts.

The above photo from http://www.golfdigest.com/golf-instruction/2012-12/sean-foley-law-of-the-draw is a good illustration of club face influence on the launch direction.

There is an exception - at high dynamic lofts >70 degrees, club face angle has little impact and club path dictates launch direction, a good example of this would be a super high lob shot, the ball starts along the swing path rather then the club face, which can be pointing to the right (for a right handed golfer)


Club Face Angle

What influences Club Face Angle?

Club Face Angle is the horizontal club face orientation at the center of contact between club face and golf ball at maximum compression of the golf ball, i.e. where the club face is pointing at the point of impact between ball and club face.

This is slightly different to club face direction. Club Face Direction is the horizontal club face orientation of the center of the club face at impact. There is a roll and bulge on driver faces, i.e. the face is curved. This affects Club Face Angle on off center hits.

Note the curvature of the face in the above photo.

On off center hits the club face angle will differ from the club face direction. Toe hits have a club face angle more to the right and heel hits more to the left.

Club Face Angle is a combination of Club Face Direction and impact point on the face. A heel shot may start on target if the club face direction offsets the club face angle at impact i.e. the club face direction is to the right. As there is no roll or bulge on an iron, this happens with woods and hybrids mainly.

Club Path

What factors influence club path? There are three major factors:

1. Swing Direction
2. Attack Angle
3. Vertical Swing Plane

Swing Direction is the horizontal direction of the plane defined by the club head's center of gravity movement prior to impacting the ball. Looking at a swing through a camera this looks like the only factor that determined club path but attack angle and vertical swing plane also determine it.

Attack Angle is the vertical direction of the club head's center of gravity movement at the maximum compression of the golf ball.

How does this affect club path? As the club is travelling down it is moving from in to out and as it is moving upward it is travelling from out to in. So if you are hitting up on a driver a swing direction will need to be positive to balance out the the negative club path value of the attack angle and create a straight launch direction.

This photo (from http://www.andrewricegolf.com/tag/trackman-article/) is an upward attack angle (pencil pointing up) with a square swing direction (hula hoop pointing straight), which gives an in to out club path (pencil is pointing left)

The hula hoop needs to be moved to the right to get the pencil pointing straight.

The amount that the swing direction needs to be compensated for the attack angle is dependent on the vertical swing plane. For a driver the vertical swing plane is close to 45 degrees, for irons it averages around 60 degrees. For a vertical swing plane of 45 degrees (driver) we get a one to one relationship between attack angle and club path i.e. if the attack is -3 a swing direction of +3 will give a straight launch direction.

For a vertical swing plane of 60 degrees (irons) there isn't a one to one relationship between attack angle and club path, it is approximately 57%, so for 1 degree of attack angle we get .57 degree of club path. With an attack angle of 4 degrees down we need a swing direction of 2.28 left to make a straight launch direction.

Summary

Club Face Angle has the biggest influence on where the ball starts. 85% influence for drivers and 75% for irons. Club Face Angle is composed of club face direction and impact point.

Club Path has some influence on where the ball starts. 15% for drivers and 25% for irons. Club Path is a combination of Swing Direction, Angle of Attack and Vertical Swing Plane.

What this means is, if your ball is not starting where you want it to, the club face angle is the main reason for this. Change the club face angle and the ball will begin to start closer to where you want it to.

Comments and questions are always welcome.