Replies to This Discussion

Permalink Reply by Rick Malm on July 17, 2009 at 3:57pm

One wants to remove bouncy hits and all backspin since these issues create variable friction grass and the result is inconsistent final roll distance. You want to get natural roll as soon as possible and remove as much slide and jumping as possible to get consistent distances. This is difficult to do with a positive loft putter and without a forward press to create neg dynamic loft at impact. Better solution is a putter with neg static loft as part of the basic design.

Permalink Reply by Corrie van Rooyen on July 18, 2009 at 1:39am

A backspin launch would rarely be advantageous at all. Once the player has 'read' the green, and has a feel for the undulations on his way to the hole, it will be a troublesome feat to get a backspinning bouncing start to get in the right direction, with the envisaged pace, to follow the envisaged path.
My putting game, which is based purely on realistic green putting, has shown me over and over that a good putt can only be achieved with a combination of the sense of establishing the green shape in 3 dimensions, followed by a practised skill to set the ball rolling on a well-planned route towards the evasive hole.
Sure - short straight putts are easy enough - but the moment the path to the hole is obstructed by challenging breaks en route, a clean putt with no bounce or backspin seems to be the only way!
For the personality/style of the player, there are some considerations to add in respect of the putter balance.
This is often overlooked, but worth some consideration and pondering.
Thanks for this group - I will certainly be watching it often to see the comments of others here.

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Permalink Reply by Jerry Pinotti on July 18, 2009 at 7:50pm

I have been a fan of negative loft for a while. I first used it on a roll face putter several years ago.

Some people I talk to about loft on a putter insist that it is necessary. The thought is that you want the ball lifted in the air to help get it rolling! They say that negative loft will cause the ball to bounce even more than a controlled loft by driving it into the ground. They feel that the back spin imparted on a ball is not as negative a factor as driving it into the ground. As I watch their stroke it appears to me that they have an unconscious forward press to eliminate the loft, but they argue I'm biased in observing them. I do not agree with them.

As someone that has studied this far more than me, can I get a technical answer to their statement.

Thanks for inviting me to this group, as someone that LOVES to putt and takes it very seriously this is great.

Permalink Reply by Duane Engdahl on July 19, 2009 at 8:06am

Greetings Corrie: I agree that Putting Judgment (reading the green) is by far the most important aspect of good putting performance and undoubtedly the most difficult skill to acquire; next would be Putting Technique (your putting style and stance); and then finally would come Putter Technology. I am in the putter technology business (providing the best tool possible for the golfer to use on the green) so that is what I am the best at. While I have some ideas on the other two aspects of putting performance, I leave that mostly up to the coaches. I look at it this way, good putting judgment requires good technique to implement it, and good putting technique requires good putter technology to implement it; so good putter technology while smaller in importance than the other two aspects, is the aspect that is fundamentally required to achieve putting perfection and it is the aspect that I can do something about (the other two aspects are up entirely to you). So you are absolutely right the the if a golfer could somehow decide on the perfect line and pace and then implement decision correctly, a putter that caused a bouncy backspin ball launch could be blamed for the missed putt, bounce and backspin being a negative to good ball movement. Thanks for your thoughtful reply, Duane

Permalink Reply by Rick Malm on July 19, 2009 at 9:34am

Here is what I have found. If the rolling surface is very hard (like pool table), to get fast natural forward roll expert pool players know that they can hit the ball with a cue stick at 7/10 the ball diameter above he table cloth and there is a very small jump but almost instant forward roll. But with a putt on grass you would drive the ball down into the soft turf and get a jump that results in distance errors. I have high speed video of doing this on a pool table and a putt on grass. As you might know, the golf ball exit or launch angle is mostly due to the face angle and only partially the path of the head.
See http://www.tutelman.com/golf/design/swing2.php?ref=#launch
or
http://trackman.dk/getmedia/2f6c5cdc-e153-466c-9e1a-f8b612947435/TM...
So to make the tradeoff with jump/bounce and getting quick forward roll you need some neg loft
but not too much. Maybe about -1 deg or so.
Depending on ground conditions you might be able to press more since you want to hit the ball
above the 5/10 ball diamater point.

Remember as you move the low point of your swing arc away from the
ball, you increase the dynamic loft, so technique of your swing is key. You can not count on your
low point being your setup address point. If you video your setup and stroke you can see where the
low point is really located. For example, if I setup with the face directly behind the ball, my low point is
about 1.5" before the ball. I have 1 deg of neg static loft at address, shaft is vertical, club face is -1 deg
in reference to the shaft. So I press 1 deg before the backswing to insure
that I will have 1 deg of neg loft at impact.

Permalink Reply by Duane Engdahl on July 20, 2009 at 7:50am

Thanks Rick for your thoughtful reply. The relatively rough soft wet surface of a golf green generates much more friction than does the relatively smooth hard dry surface of a pool table and that is a very important difference. Topspin roll is created by two torques (offset force) upon the ball: 1) an impact point above the center of the ball which generates forward torque and 2) frictional force of the surface upon the bottom of the ball which generates a backward torque. A putter head with a negative loft angle not only impacts above the center line of the ball causing topspin torque, it also ever so slightly pushes the ball into the surface of the green thus increasing the frictional counter torque and the combination of these two torques is what creates the topspin. A cue stick when it impacts the ball must impact at a higher point to achieve the same result because it does not generate much if any downward pressure upon the cue ball and even even if it did the frictional qualities of the pool table are much less than those of the golf green.

Rick Malm said:

Here is what I have found. If the rolling surface is very hard (like pool table), to get fast natural forward roll expert pool players know that they can hit the ball with a cue stick at 7/10 the ball diameter above he table cloth and there is a very small jump but almost instant forward roll. But with a putt on grass you would drive the ball down into the soft turf and get a jump that results in distance errors. I have high speed video of doing this on a pool table and a putt on grass. As you might know, the golf ball exit or launch angle is mostly due to the face angle and only partially the path of the head.
See http://www.tutelman.com/golf/design/swing2.php?ref=#launch or http://trackman.dk/getmedia/2f6c5cdc-e153-466c-9e1a-f8b612947435/TM... So to make the tradeoff with jump/bounce and getting quick forward roll you need some neg loft
but not too much. Maybe about -1 deg or so.
Depending on ground conditions you might be able to press more since you want to hit the ball
above the 5/10 ball diamater point.

Remember as you move the low point of your swing arc away from the
ball, you increase the dynamic loft, so technique of your swing is key. You can not count on your
low point being your setup address point. If you video your setup and stroke you can see where the
low point is really located. For example, if I setup with the face directly behind the ball, my low point is
about 1.5" before the ball. I have 1 deg of neg static loft at address, shaft is vertical, club face is -1 deg
in reference to the shaft. So I press 1 deg before the backswing to insure
that I will have 1 deg of neg loft at impact.

Permalink Reply by Duane Engdahl on July 20, 2009 at 8:23am

Thanks Jerry for the thoughtful reply. For years this misconception about a putter needing loft to lift it out an indentation so it can achieve positive roll, has been floating around the golf world. I think it has been perpetuated by Pelz and his followers for so long that it has become golfing folklore which most of the major putter makers have bought into it hook line and sinker (which goes to show you that the major golf putter makers are more influenced by their marketeers than by their engineers). The principal of mechanics at work in this issue is easily understood by physicists and engineers and by anyone else who is willing to understand the following well established and settled science: Topspin on a golf ball is created by two opposing torques: 1) ball impact above the center of the ball which creates not only forward motion but also forward torque, and 2) friction of the surface of the green upon the ball which creates a backward torque. The combination of the forward torque upon the top of the ball and the backward torque upon the bottom of the ball is what creates the topspin roll. A negative loft putter actually increases the frictional counter torque by pushing the ball slightly into the green, and that of course increases forward spin even further. Now if you loft the ball into the air not only does the lofting create a backspin due to the impact point being below the ball's center, the air creates no opposing torque to counter that backspin. Try explaining it to your friends this way and maybe they will understand. Best regards, Duane.

Jerry Pinotti said:

I have been a fan of negative loft for a while. I first used it on a roll face putter several years ago.
Some people I talk to about loft on a putter insist that it is necessary. The thought is that you want the ball lifted in the air to help get it rolling! They say that negative loft will cause the ball to bounce even more than a controlled loft by driving it into the ground. They feel that the back spin imparted on a ball is not as negative a factor as driving it into the ground. As I watch their stroke it appears to me that they have an unconscious forward press to eliminate the loft, but they argue I'm biased in observing them. I do not agree with them.
As someone that has studied this far more than me, can I get a technical answer to their statement.

Thanks for inviting me to this group, as someone that LOVES to putt and takes it very seriously this is great.