ball-flight and varying the true clubpath orientation at impact

8/2/2019 Ball-Flight and Varying the True Clubpath Orientation at Impact

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Ball-Flight - Varying the True Clubpath Orientation at Impact

The clubface (CF) orientation at impact and the true clubpath (CP) orientation at

mpact determine the balls flight.

The true CP orientation at impact is calculated by the following equation:

True CP = HSP [AA * TAN (90 VSP)]

Vertical Swing Plane (VSP) (or Swing Plane) is a measure of how vertical the swing is, where a high valu

epresents a very up and down (steep) swing plane and a low value is a relatively flat (to the ground) arc. Mo

echnically, it is the angle made between the ground and the plane of club head trajectory at the bottom of the

wing arc. The higher your VSP (the steeper your swing plane) the less effect the AA has on your true CP and

vice versa.

Horizontal Swing Plane (HSP) (or Swing Direction) is the orientation of the swing arc, relative to the tar

ine, where positive means to the right, negative means to the left. More technically, it is the horizontal directi

he club head is traveling in the bottom of the swing arc.

Angle of Attack (AA) (or Attack Angle) is the vertical (up-down) angle at which the club head is moving a

mpact. Positive means hitting up on the ball, while negative means hitting down on the ball. If your AA is zer

you swing dead level), then your true CP will simply be your HSP.

With shots off the ground, you want to have a negative AA. With a driver, you want to have a positive AA or a

light negative AA (which ever works best for you).

Spin Axis:

The spin axis is the axis around which a golf ball spins. The value is plus or minus relative to the horizon. A

positive value means the ball is going right and a negative value means the ball is going left.

The spin axis tilt is calculated as 2 times the difference between the true club path (CP) orientation at impact

he clubface (CF) orientation at impact. A golf ball will spin sideways 0.7 percent for every one degree of spin

axis tilt.

Off Center Hits:


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There are two contributions to tilting the spin axis. The first is the tilting when the true CP orientation at imp

does not equal the CF orientation at impact. The second contribution is the horizontal gear effect that occurs

when the ball is impacted anywhere but the center of gravity of the clubhead in the heel-toe direction. If the b

s hit toward the toe, the clubhead will twist clockwise and the gear effect causes the ball spin axis to tilt left

counter-clockwise, draw spin). If the ball is hit toward the heel, you get the opposite effect, or fade spin axis t

A one dimple (0.14 inches) off center hit creates a 6-degree tilting of the spin axis. For every 10 degrees of sp

axis tilt, the ball spins sideways by 7 percent.

nitial Ball Flight Direction:

The initial ball -flight direction will be approximately 75 to 35 percent in the direction of the CF orientation a

mpact relative to the true CP orientation at impact. A driver will be closer to the 75 percent and a wedge clos

o the 35- percent. The ball will then curve away from the true CP orientation.

To hit the ball straight, you need to zero out the true CP and orientation at impact with the CF orientation at

mpact.

Playing a Draw:

f you like to play a slight draw, you would want your true CP orientation at impact inside of +3 degrees (in-to

out path) with a CF orientation near zero at impact. Tour players that have a sizable draw swing in-to-out wit

rue CP orientation at impact of approximately +6 degrees. You do not want do have the CF orientation at imp

oo closed relative to the true CP orientation at impact because this will cause the ball to curve too much righ

o-left.The following picture depicts a true CP orientation at impact of plus 6 degrees and a CF orientation at impact

ero degrees.


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Degree of Spin Axis Tilt= 2 * (angle of difference between the true CP and CF

orientations at impact)

Percent Sideways Curve = 0.7 * Degree of Spin Axis Tilt

Amount of Sideways Curve = Distance of Shot * Percent of Sideways Curve

nitial Starting Direction of the Ball Flight (Assumptions)

For a Driver = 75 percent in the direction of the CF orientation at impact relative the true CP orientation at impact.

For a Four-Iron = 55 percent in the direction of the CF orientation at impact

relative to the true CP orientation at impact.

For a Wedge = 35 percent in the direction of the CF orientation at impact relative

the true CP orientation at impact.

End of Shot Distance from Target= Amount of Sideways Curve minus the Initial

Start of Ball

The following calculations (for a driver, four-iron, and wedge) assume there is zer

gear effect (i.e. no off-center hit). All distances are flight distances and do not inclu

any bounce/roll-out distance.


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Driver Shots Varying The True CP Orientation at Impact

Table 1 - True CP Orientation at Impact is Plus 6 Degrees; CF Orientation at

mpact is Zero Degrees.

Carry

Distance

to

Target

Degree

of Spin

Axis

Tilt

Percent

Sideways

Curve

Amount

of

Sideways

Curve

Initial Start

of Ball (Right

of Target)

End of Shot

Distance from

Target

300

yards

12 8.4 25.2

yards

31.5 (.75 *

31.5) = 7.9

yards

17.3 yards left of

target

250

yards

12 8.4 21 yards 26.3 - (.75 =

26.3) = 7.05

yards

13.95 yards left

of target

Table 2 True CP Orientation at Impact is Plus 3 Degrees; CF Orientation at

mpact is Zero Degrees

CarryDistance

to

Target

Degreeof Spin

Axis

Tilt

PercentSideways

Curve

Amountof

Sideways

Curve

Initial Startof Ball (Right

of Target)

End of ShotDistance from

Target

300

yards

6 4.2 12.6

yards

15.7 (.75 *

15.7) = 3.9

yards

8.7 yards left of

target

250

yards

6 4.2 10.5

yards

13.1 - (.75 =

13.1) = 3.3yards

7.2 yards left of

target

Table 3 True CP Orientation at Impact is Plus 1.5 Degrees; CF Orientation at



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Carry

Distance

to

Target

Degree

of Spin

Axis

Tilt

Percent

Sideways

Curve

Amount

of

Sideways

Curve

Initial Start

of Ball (Right

of Target)

End of Shot

Distance from

Target

300yards

3 2.1 6.3 yards 7.9 (.75 *7.9) = 2

yards

4.3 yards left oftarget

250

yards

3 2.1 5.25

yards

6.5 - (.75 =

6.5) = 1.6

yards

3.7 yards left of

target

Table 4 True CP Orientation at Impact is Plus 3 Degrees; CF Orientation atmpact is Plus 1.5 Degrees

Carry

Distance

to

Target

Degree

of Spin

Axis

Tilt

Percent

Sideways

Curve

Amount

of

Sideways

Curve

Initial Start

of Ball (Right

of Target)

End of Shot

Distance from

Target

300

yards

3 2.1 6.3 yards 15.7 (.75 *

15.7) = 3.9

yards

2.4 yards left of

target

250

yards

3 2.1 5.25

yards

13.1 - (.75 =

13.1) = 3.3

yards

1.95 yards left

of target

Four Iron Shots Varying the True CP Orientation at Impact

Table 1 - True CP Orientation at Impact is plus 6 Degrees; CF Orientation at



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Carry

Distance

to

Target

Degree

of Spin

Axis

Tilt

Percent

Sideways

Curve

Amount

of

Sideways

Curve

Initial Start

of Ball (Right

of Target)

End of Shot

Distance from

Target

200yards

12 8.4 16.8yards

21 (.55 *21) = 9.5

yards




Carry

Distanceto

Target

Degree

of SpinAxis

Tilt

Percent

SidewaysCurve

Amount

ofSideways

Curve

Initial Start

of Ball (Rightof Target)

End of Shot

Distance fromTarget

200

yards

6 4.2 8.4 yards 10.5 (.55 *

10.5) = 4.7

yards

3.7 yards left of

target

Table 3 True CP Orientation at Impact is Plus 1.5 Degrees; CF Orientation atmpact is Zero Degrees.

Carry

Distance

to

Target

Degree

of Spin

Axis

Tilt

Percent

Sideways

Curve

Amount

of

Sideways

Curve

Initial Start

of Ball (Right

of Target)

End of Shot

Distance from

Target

200

yards

3 2.1 4.2 yards 5.2 (.55 *

5.2) = 2.3

yards

1.9 yards left of

target


mpact is 1.5 Degrees


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Carry

Distance

to

Target

Degree

of Spin

Axis

Tilt

Percent

Sideways

Curve

Amount

of

Sideways

Curve

Initial Start

of Ball (Right

of Target)

End of Shot

Distance from

Target

200yards

3 2.1 4.2 yards 10.5 (.55 *10.5) = 4.7

yards

.5 yards right oftarget

Wedge Shot Varying the True CP Orientation at ImpactTable 1 - True CP Orientation at Impact is Plus 6 Degrees; CF Orientation at


Carry

Distance

to

Target

Degree

of Spin

Axis

Tilt

Percent

Sideways

Curve

Amount

of

Sideways

Curve

Initial Start

of Ball (Right

of Target)

End of Shot

Distance from

Target

100yards

12 8.4 8.4 yards 10.5 (.35 *10.5) = 6.8

yards


50

yards

12 8.4 4.2 5.3 (.35 *

5.3) = 3.4

yards

.8 Yards left of

target



Carry

Distance

to

Target

Degree

of Spin

Axis

Tilt

Percent

Sideways

Curve

Amount

of

Sideways

Curve

Initial Start

of Ball (Right

of Target)

End of Shot

Distance from

Target


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100

yards

6 4.2 4.2 yards 5.2 (.35 *

5.2) = 3.4

yards

.8 yards left of

target

50

yards

6 4.2 2.1 yards 2.6 (.35 *

2.6) = 1.7yards

.4 yards left of

target

Table 3 True CP Orientation at Impact is Plus 1.5 Degrees; CF Orientation at


Carry

Distance

toTarget

Degree

of Spin

AxisTilt

Percent

Sideways

Curve

Amount

of

SidewaysCurve

Initial Start

of Ball (Right

of Target)

End of Shot

Distance from

Target

100

yards

3 2.1 2.1 yards 2.6 (.35 *

2.6) = 1.7

yards

.4 yards left of

target

50

yards

3 2.1 1 yard 1.3 (.35 *

1.3) = .84

yards

.16 yards left of

target


mpact is Plus 1.5 Degrees

Carry

Distance

to

Target

Degree

of Spin

Axis

Tilt

Percent

Sideways

Curve

Amount

of

Sideways

Curve

Initial Start

of Ball (Right

of Target)

End of Shot

Distance from

Target

100yards

3 2.1 2.1 yards 5.2 (.35 *5.2) = 3.9

yards


50

yards

3 2.1 1 2.6 (.35 *

2.6) = 1.7

yards

.7 yard left of

target


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Playing a Fade:f you like playing a slight fade, you would want your true CP orientation at impact inside of -3 degrees (out-t

path) with a CF orientation near zero at impact. Tour players that have a sizable fade swing out-to-in with a tr

CP orientation of -6 degrees. You do not want to have the CF orientation at impact too open relative to the tru

CP orientation at impact because this will cause the ball to curve too much left-to-right.

The following picture depicts a true CP orientation at impact of minus 6 degrees and a CF orientation at impa

of zero degrees.


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Degree of Spin Axis Tilt= 2 * (angle of difference between the true CP and CF

orientations at impact)

Percent Sideways Curve = 0.7 * Degree of Spin Axis Tilt

Amount of Sideways Curve = Distance of Shot * Percent of Sideways Curve

The following calculations (for a driver, four-iron, and wedge) assume there is no

gear effect (i.e. no off-center hit) and a CF orientation at impact of zero degrees.

nitial Starting Direction of the Ball Flight (Assumptions)

For a Driver = 75 percent in the direction of the CF orientation at impact relative


For a Four-Iron = 55 percent in the direction of the CF orientation at impact

relative to the true CP orientation at impact.

For a Wedge = 35 percent in the direction of the CF orientation at impact relative


End of Shot Distance from Target= Amount of Sideways Curve minus the Initial

Start of BallThe following calculations (for a driver, four-iron, and wedge) assume there is zer

gear effect (i.e. no off-center hit). All distances are flight distances and do not inclu

any bounce/roll-out distance.

Driver Shots Varying The True CP Orientation at Impact

Table 1 - True CP Orientation at Impact is Minus 6 Degrees; CF Orientation a



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Carry

Distance

to

Target

Degree

of Spin

Axis

Tilt

Percent

Sideways

Curve

Amount

of

Sideways

Curve

Initial Start

of Ball (Left

of Target)

End of Shot

Distance from

Target

300yards

12 8.4 25.2yards

31.5 (.75 *31.5) = 7.9

yards

17.3 yards rightof target

250

yards

12 8.4 21 yards 26.3 - (.75 =

26.3) = 7.05

yards

13.95 yards

right of target

Table 2

True CP Orientation at Impact is Minus 3 Degrees; CF Orientation ampact is Zero Degrees

Carry

Distance

to

Target

Degree

of Spin

Axis

Tilt

Percent

Sideways

Curve

Amount

of

Sideways

Curve

Initial Start

of Ball (Left

of Target)

End of Shot

Distance from

Target

300

yards

6 4.2 12.6

yards

15.7 (.75 *

15.7) = 3.9

yards

8.7 yards right

of target

250

yards

6 4.2 10.5

yards

13.1 - (.75 =

13.1) = 3.3

yards

7.2 yards right

of target

Table 3 True CP Orientation at Impact is Minus 1.5 Degrees; CF Orientation a


CarryDistance

to

Target

Degreeof Spin

Axis

Tilt

PercentSideways

Curve

Amountof

Sideways

Curve

Initial Startof Ball (Left

of Target)

End of ShotDistance from

Target

300

yards

3 2.1 6.3 yards 7.9 (.75 *

7.9) = 2

4.3 yards right

of target


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yards

250

yards

3 2.1 5.25

yards

6.5 - (.75 =

6.5) = 1.6

yards

3.7 yards right

of target

Table 4 True CP Orientation at Impact is Minus 3 Degrees; CF Orientation at

mpact is Minus 1.5 Degrees

Carry

Distance

to

Target

Degree

of Spin

Axis

Tilt

Percent

Sideways

Curve

Amount

of

Sideways

Curve

Initial Start

of Ball (Left

of Target)

End of Shot

Distance from

Target

300yards

3 2.1 6.3 yards 15.7 (.75 *15.7) = 3.9

yards

2.4 yards rightof target

250

yards

3 2.1 5.25

yards

13.1 - (.75 =

13.1) = 3.3

yards

1.95 yards right

of target

Four Iron Shots Varying the True CP Orientation at Impact

Table 1 - True CP Orientation at Impact is Minus 6 Degrees; CF Orientation a


Carry

Distance

to

Target

Degree

of Spin

Axis

Tilt

Percent

Sideways

Curve

Amount

of

Sideways

Curve

Initial Start

of Ball (Left

of Target)

End of Shot

Distance from

Target

200

yards

12 8.4 16.8

yards

21 (.55 *

21) = 9.5

yards

7.3 yards right

of target


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Table 2 True CP Orientation at Impact is Minus 3 Degrees; CF Orientation a


Carry

Distanceto

Target

Degree

of SpinAxis

Tilt

Percent

SidewaysCurve

Amount

ofSideways

Curve

Initial Start

of Ball (Leftof Target)

End of Shot

Distance fromTarget

200

yards

6 4.2 8.4 yards 10.5 (.55 *

10.5) = 4.7

yards

3.7 yards right

of target



Carry

Distance

to

Target

Degree

of Spin

Axis

Tilt

Percent

Sideways

Curve

Amount

of

Sideways

Curve

Initial Start

of Ball (Left

of Target)

End of Shot

Distance from

Target

200

yards

3 2.1 4.2 yards 5.2 (.55 *

5.2) = 2.3

yards

1.9 yards right

of target

Table 4 True CP Orientation at Impact is Minus 3 Degrees; CF Orientation at

mpact is Minus 1.5 Degrees

Carry

Distance

to

Target

Degree

of Spin

Axis

Tilt

Percent

Sideways

Curve

Amount

of

Sideways

Curve

Initial Start

of Ball (Left

of Target)

End of Shot

Distance from

Target

200

yards

3 2.1 4.2 yards 10.5 (.55 *

10.5) = 4.7

yards

.5 yards left of

target


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Wedge Shot Varying the True CP Orientation at Impact

Table 1 - True CP Orientation at Impact is minus 6 Degrees; CF Orientation a


Carry

Distance

to

Target

Degree

of Spin

Axis

Tilt

Percent

Sideways

Curve

Amount

of

Sideways

Curve

Initial Start

of Ball (Left

of Target)

End of Shot

Distance from

Target

100

yards

12 8.4 8.4 yards 10.5 (.35 *

10.5) = 6.8

yards

1.6 yards right

of target

50

yards

12 8.4 4.2 5.3 (.35 *

5.3) = 3.4

yards

.8 Yards right of

target

Table 2 True CP Orientation at Impact is Minus 3 Degrees; CF Orientation a


Carry

Distance

to

Target

Degree

of Spin

Axis

Tilt

Percent

Sideways

Curve

Amount

of

Sideways

Curve

Initial Start

of Ball (Left

of Target)

End of Shot

Distance from

Target

100

yards

6 4.2 4.2 yards 5.2 (.35 *

5.2) = 3.4

yards

.8 yards Right of

target

50

yards

6 4.2 2.1 yards 2.6 (.35 *

2.6) = 1.7

yards

.4 yards Right of

target




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Page 15 of 15

Carry

Distance

to

Target

Degree

of Spin

Axis

Tilt

Percent

Sideways

Curve

Amount

of

Sideways

Curve

Initial Start

of Ball (Left

of Target)

End of Shot

Distance from

Target

100yards

3 2.1 2.1 yards 2.6 (.35 *2.6) = 1.7

yards

.4 yards right oftarget

50

yards

3 2.1 1 yard 1.3 (.35 *

1.3) = .84

yards

.16 yards right

of target

Table 4 True CP Orientation at Impact is Minus 3 Degrees; CF Orientation atmpact is Minus 1.5 Degrees

Carry

Distance

to

Target

Degree

of Spin

Axis

Tilt

Percent

Sideways

Curve

Amount

of

Sideways

Curve

Initial Start

of Ball (Left

of Target)

End of Shot

Distance from

Target

100

yards

3 2.1 2.1 yards 5.2 (.35 *

5.2) = 3.9

yards

1.8 yards right

of target

50

yards

3 2.1 1 2.6 (.35 *

2.6) = 1.7

yards

.7 yard right of

target

ball-flight and varying the true clubpath orientation at impact

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