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Putter
Loft vs. Roll Test (VIDEO) /
 The
information for a player to pick the best putter and then
get it fitted for the correct loft for the putter is clouded
by marketing. Manufactures drive to have something different
that might make a putter look different but the difference
often have little effect on the actual response. To the
purpose of this one test, was to observe exactly what happens
to a golf ball when impacted by putters of various general
kinds of putter design including those with impact pads
and those without, those with grooves on impact surface
and those that have smooth impact surfaces; those that are
heel shafted and those that are center shafted, those which
have a relatively small front to back dimension (blades)
and those which have large front to back size dimension
(mallets), and most important those which have positive
loft and those which have negative loft.
It is not the intent to promote or disparage any putter
brand, and so the test putters by their characteristics
only and
not by their brand names, and we will not select putters
on the basis of brand name but only on the basis of the
characteristics needed for the test; e.g., while there are
many brands of blade putters having positive loft angles
and no impact pad and no grooves, the one that we happen
to select for the test is based only upon easy availability
and not upon any a-priori brand preference. The putters
selected provided a loft range from -1 to 5.5 degrees. The
goal of the test was to help the author decided what new
putter loft to start using.
In the process of make preliminary tests, some variability
was seen in the results due to the dimples on a golf ball
so a Bald Eagle Ball was used which, while it is dimpled
as is typical of golf balls, it has un-dimpled areas which
we can use for putter impact so that this dimple issue has
no bearing upon this study.
The surface of any golf green has a myriad of variables
which are extremely difficult if not impossible to quantify,
and these variables greatly affect golf ball movement. So
the test were conduct this testing in a laboratory environment
on a perfectly level pool table surface which has a reliably
hard and smooth and level surface which is covered by a
consistently textured cloth. The 1st test was on a fast
billiard cloth an the 2nd was done with a stimp 11 putting
carpet. Thus all the myriad of golf green unknowns that
would prevent us from drawing conclusions from the testing
are factored out.
Whether to use a human or a robot to stroke the putter was
a difficult decision. A robot would give absolute consistency
of stroke, but no robot yet made can replicate the stroke
of a human. Since this testing would be observed in ultra
slow motion and and has the ability to precisely measure
all aspects of the stroke, so a human was used for stroking
and simply reject those human strokes that exhibit any human
error in stroking. Thus there is the benefit of an actual
human putting stroke with all its complexity, yet one can
exercise the control necessary for good scientific testing.
Obviously we need a human who has well developed putting
skill so we do not have to reject so many putts due to observed
human error.
In testing a consistent stroke strength which is about what
it would take to roll a ball on a level golf green about
10 feet. Putts under 5 ft are usually made by any kind golfer
using any kind of putter; putts over 15 feet are usually
missed by any kind of golfer using any kind of putter; but
putts between these two extremes (10 ft putt plus/minus
5 ft) is where the kind of putter that a golfer uses can
make the difference between making or missing the putt.
So it seemed logical that this is the stroke strength of
interest. Stroke strength can be precisely measured by counting
the number of frames of slow motion video it takes for the
ball to move a given distance, so any stroke strength significantly
greater or lesser than that desired will be considered human
error and rejected.
The objective of this test is to observe golf ball movement
after putter impact to observe: 1) Down-Line quarter roll
and half roll. Down-Line Roll can be: a) topspin, b) backspin,
or c) no spin (skid); and most would agree that topspin
is desirable over the other two. Putting is a rolling ball
game and obviously an airborne launch is the cause of ball
bounce, which most would agree is undesirable in comparison
with rolling bounce-less launch.
To perform
a loft test the ball movement was observed resulting from
impact by three different putters: 1) a putter having a
negative loft angle, 2) a putter having no loft angle at
all, and 3) by a putter having a positive loft angle. Since
the effective loft angle incident upon the ball at impact
consists of a combination of the static loft angle of the
putter (that is its published loft angle or the angle as
it is measured statically), the press of the golfer in his
putting stance (the angle of the putter shaft at impact
as viewed out perpendicular from the desired line of the
putt with a forward press reducing effective loft and a
backward press increasing effective loft), and the placement
of the ball forward or backward from the point of tangency
of the stroke arc with the green (backward placement causing
a decrease in effective loft and forward causing an increase
in effective loft). In order to eliminate the factors of
press and placement and so to concentrate only on the factor
of static loft angle, human to stroke was made such that
the ball was impacted at the low point of stroke path tangent
and with the putter shaft perfectly vertical such that the
press and placement were factored out, and the only static
loft is effecting the ball motion; The human tried to always
impact the ball with the stroke strength approximating a
10 ft putt so stroke strength could also be factored out
of the test. Many strokes are to be made with each putter
and then after analyzing the slow motion videos, all those
with any significant human error will be discarded so that
hopefully we end up with three objective representations
of ball movement (one for each of the three putter types)
upon which we may be able to make some sound scientific
conclusions.
What about all the variations in putter design, don’t
they adversely affect any conclusions that might be drawn
from these tests? Yes maybe, but that simply points out
the need for further future testing. In this testing, we
have done our best to isolate on the factors that we sincerely
believe to be relevant for the test which was intended to
be performed and leave the testing of all other factors
for another time. For example, do groves or pads in the
impact area of the putter head effect ball launch?.. Maybe
yes, maybe now – we think not significantly, but that
is the subject of another test. For another example, does
the mass of the putter head effect ball launch?.. Of course
mass is a function of putter power so that would that would
effect the distance the ball will travel, given equal stroke
velocity, but does it affect the spin or bounce of the ball?..
We think not, but the proof of this will have to be the
subject of another study. For yet another example, does
the shape of the putter behind the striking face have an
effect upon ball launch?.. We think not unless the shape
alters the perfect vectoring of the shaft into the center
of mass of the putter head, in which case we believe that
shape does matter, but again that will have to be left for
another study.
What about variations in fitting, doesn’t that have
an adverse effect on any conclusions you might draw? No
actually not, because fitting factors affect human performance,
good fitting makes it easier to perform the putting stroke
perfectly, bad fitting makes it more difficult. The human
performing all the putting strokes in this testing is actually
using poorly fitted putters for his putting style and stature,
and that does not affect the test because upon analysis
of his putting strokes, we reject any of the strokes that
do not meet testing requirements. So the result of poor
fit is that more of those putting strokes are rejected than
would otherwise be the case if he were perfectly fitted.
What about variations in Gripping and Back-weighting? No
these factors are not important to this test for the same
reason stated in the previous paragraph. Of course these
factors may improve putting performance in some way or by
some degree, but that is a subject of another test; in this
test whether they make a difference in performance is irrelevant
because we reject any significant human error during our
analysis anyway.
The 300 frame per sec video of each test putt was reviewed
and the result were measured. The video files were each
named to have the measurement recorded in the file names.
For those that want to see the raw data, the following is
the file naming convention.
The
1st token in the file name is related to the manufacture
and or model name.
The 2nd is CHS or club head speed measured in the number
of frames it takes for the head to traverse 3 inches prior
to impact.
The next 3 fields in the file name were to describe the
loft.
ML: means the manufacturer's published loft angle,
SL means the push/pull (press) angle of the shaft which
ideally for the test is zero,
DL which means dynamic loft which is the sum of ML and SL.
Then the next field or token was QR which means the distance
in inches it took for the all to achieve quarter roll. HR
is the measurement of the distance in inches it took for
the ball to achieve half roll. In some cases the total weight
was specified as the value after the characters GR.
The
results show that increasing the negative loft reduces the
forward roll distance. The following are the plots of quarter
roll and half roll vs loft that summarize the findings of
the two surface types.
BILLIARD
CLOTH TESTS
Mitchell
MCS
Chs18 SL0 ML3 DL3 QR 10.4 HR14.4
MHS
Chs17.5 SL0 ML3 DL3 QR12.4 HRna
Odyssey
O2B
Chs18.5 SL0 ML4 DL4 QR10.7 HR11.7
Ping
PCA
Chs19 SL0 ML4 DL4 QR11.7 HR15.1
PCRAZE
Chs19 SL0 ML4 DL4 QR10.7 HR11.8
Pirana
PIR
Chs19 SL-0.5 ML2.5 DL 1.5 QR8.6 HR11.9
Quantum
Qx
Chs18 SL0 ML -1 DL-1 QR8 HR9.2
Qx
Chs18 SL-1 ML-1 DL-2 QR8.4 HR12
Qxx
Chs18 SL0 ML-1 DL-1 QR 8.4 HR 11.8
Qxxx
Chs19.5 SL0 ML-1 DL-1 QR8.5 HR11.9
QxxxB
Chs19 SL0 ML-0.5 DL-0.5 QR8.3 HR11.5
SCS
SCS
Chs18 SL0 ML4 DL4 QR11 HRna
STX
STXm5
Chs19 SL0 ML0 DL0 QR8.5 HR11.5
Taylor
Made
TMSPID
Chs18 SL-0.5 ML4 DL3.5 QR9.2 HR12.2
Utopia
(special - no loft measure, so hit at different heights)
UTe
Chs19 QR9 HR12.3 (Equator Hit)
UTL
Chs16 NegR0.125at9.4 NoRoll12.5 (Low Hit)
Utvh
Chs19 QR4 HR7.2 FR11 (High Hit)
YAR
YAR
Chs18 SL0 ML-1 DL-1 QR8.1 HR11.2
Yes
Yhan
CHS19 SL0 ML0 DL0 Low1.5in before LA 1deg QR8 HR11.2
Yhan
Chs20.5 SL-1.4 ML0 DL-1.4 Low2inBeforeImpactPint LA5deg
QR 6.75 HR 10 at 600fpsView
Yhan
Chs21 SL0.5 ML0 DL-0.5 Low2inahead LA-1deg QR 7.5 at 600fpsView
CARPET
TESTS (11 on Stimpmeter)
Mitchell
Mitchell
CS350 GR526 Chs17 SL0 ML3 DL3 QR9.2 HR12.2
Mitchell
CS350 GR526 Chs18 SL0 ML3 DL3 QR8.4 HR11.3
Ping
Ping
Anser GR475 Chs18.5 SL0 ML6 DL6 QR8.3 HR10.9
Ping
Anser GR475 Chs17.5 SL0 ML6 DL6 QR10.2 HR13.2
Piranha
Piranha
GLO10 GR625 chs19 SL0 ml2 dl2 QR7.5 HR 10.5
Piranha
GLO10 GR625 Chs18 SL0 ML2 DL2 QR8.1
Quantum
Quantum
Qxx GR619 Chs18 SL 0 ML -1 DL -1 QR 6.5 HR 9.3
Sblade
Sblade
GR630 chs17 SL 0 QR 8 HR 11
Sblade
GR630 chs17 SL 0 ML 1 DL 0 QR 8 HR 11
Yes
Yes
Hanna GR775bw300 Chs17 SL0 ML 0 DL0 QR 8 HR 11.2
Yes
Hanna GR775bw300 Chs18 DL-2 QR6.5 HR 9.3
Whether
to use a human or a robot to stroke the putter was a difficult
decision. A robot would give absolute consistency of stroke,
but no robot yet made can replicate the stroke of a human.
Since this testing would be observed in ultra slow motion
and we have the ability to precisely measure all aspects
of the stroke, so we can use a human for stroking and simply
reject those human strokes that exhibit any human error
in stroking. Thus we have the benefit of an actual human
putting stroke with all its complexity, yet we can exercise
the control necessary for good scientific testing. Yes,
we could have used a robot for putter loft and impact surface
testing; but when testing for the significance of head twist
on ball launch we could not because a robot would fasten
to the shaft in such a way that head twist is prevented
from twisting, while a human would hold the grip in such
a way that head twist may be very significant.
Which
human do we select for this job? Obviously we need a human
who has well developed putting skill so we do not have to
reject so many putts due to observed human error. So we
selected Rick Malm, an avid golfer who is also an Artistic
Pool Champion (trick shot champion for those who don’t
follow the sport of pool that much). Artistic pool requires
extraordinary skill, excellent hand-eye coordination, and
precision muscle control; Rick has all that not only for
the sport of pool but also for the sport of golf, so he
is the perfect human to use for this testing. Rick is also
a retired IBM Researcher with 30 years experience in computer
architecture, graphics and data analysis. Rick has the high
speed camera equipment that he uses for analysis of elite
athletes in golf (Long Drive and PGA tour pros).
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