Putter Arc off mirror

[Sp4zRX]

When I practice with a putting mirror, the low point of my putting arc is slightly higher from the ground, simply because the mirror is on the ground. It seems the mirror forces me to strike the ball slightly higher than I do without the mirror. The result seems to be that I strike the ball pure more often with the mirror. 
 

My question is if the mirror is actually training a better impact location on the ball or should the arc actually swing closer to the ground?

[Shankapotimous]

Great question and I was wondering the same. 

[Soloman1]

You should have the putter elevated at impact for a better strike.

 

Most putter faces are ~1” in height, the ball is an average of 1.69” in diameter, so the equator is 0.85”.

 

Elevating the face approximately 3/8” will strike near the vertical center of the face and at the equator of the ball.

 

If you strike below the equator, the ball launches higher with more bounce and skid and extends the distance until it rolls end-over-end.

Edited July 14, 2023 by Soloman1
corrected equator (sorry)

[PracticeSwinger]

35 minutes ago, Soloman1 said:

You should have the putter elevated at impact for a better strike.

 

Most putter faces are ~1” in height, the ball is an average of 1.69” in diameter, so the equator is 0.35”.

 

Elevating the face approximately 3/8” will strike near the vertical center of the face and at the equator of the ball.

 

If you strike below the equator, the ball launches higher with more bounce and skid and extends the distance until it rolls end-over-end.

Great precision, thanks! If my math is correct (that's not a given) : putter face 1" inch high, elevated 3/8" and the equator of the ball is 1/3" high that produces a strike that is really low of the putter face, correct?

[Soloman1]

1 hour ago, Varry_Hardon said:

Great precision, thanks! If my math is correct (that's not a given) : putter face 1" inch high, elevated 3/8" and the equator of the ball is 1/3" high that produces a strike that is really low of the putter face, correct?

 

Equator of the ball is dIameter / 2

1.69” / 2” = 0.845” from ground.

 

Center of face is 0.5 “ from ground.

 

0.845 - 0.5 = 0.345 (~3/8”) elevation for strike at equator of ball at center of face.

 

Kind of like hitting a cue ball, right? Hit the cue ball at or just above the equator if you want to roll it smoothly without backspin.

 

 

[PracticeSwinger]

2 minutes ago, Soloman1 said:

 

Equator of the ball is dIameter / 2

1.69” / 2” = 0.845” from ground.

 

Center of face is 0.5 “ from ground.

 

0.845 - 0.5 = 0.345 (~3/8”) elevation for strike at equator of ball at center of face.

 

Kind of like hitting a cue ball, right? Hit the cue ball at or just above the equator if you want to roll it smoothly without backspin.

 

 

Got it, was confused with your first post that had the equator at 0.35". No biggy, moving along. We got more important stuff to discuss, pronation, trackman and Bryson to name a few!

[iacas]

9 hours ago, Soloman1 said:

Kind of like hitting a cue ball, right? Hit the cue ball at or just above the equator if you want to roll it smoothly without backspin.

 

Except a pool cue is not like a flat putter face, so the only way you're hitting above the equator with a putter is with negative (effective) loft at impact.

 

You can hit below the equator and get a small amount of forward spin: Loft is 1°, AoA is 3°.

[virtuoso]

Yeah, hitting the ball above the equator will squish the ball into the ground. I wouldn’t advise it.

[Soloman1]

I agree.

 

My testing shows best energy transfer and consistently forward spin with 0 AoA (bottom of vertical arc) and strike at equator.

 

A positive AoA usually results in strike at bottom of the face which reduces energy transfer.

 

Here is 50 putts with strike at equator of ball with 0 AoA.

 

Result was forward spin average and distance to true roll average significantly reduced from usual 15%-20%+ of distance to the hole.

 

 

 

[virtuoso]

What is the launch angle on those putts?

 

please note: a functional roll on the ball is not necessarily about maximizing topspin or energy transfer.

Edited July 15, 2023 by virtuoso

[Soloman1]

Yes, they're just two things and not everything. More energy transfer requires less velocity (the stroke can be slower and more controlled) and reducing bounce further reduces energy loss. Do you want more bounce and skid until true roll?

 

I'm not talking about read, path, face angle, MOI , etc.

 

What are your functional roll parameters?

[virtuoso]

1 hour ago, Soloman1 said:

Yes, they're just two things and not everything. More energy transfer requires less velocity (the stroke can be slower and more controlled) and reducing bounce further reduces energy loss. Do you want more bounce and skid until true roll?

 

I'm not talking about read, path, face angle, MOI , etc.

 

What are your functional roll parameters?

If you get the ball into true roll sooner, will a certain ball speed at impact end up rolling out farther?

[Soloman1]

 

5 hours ago, virtuoso said:

If you get the ball into true roll sooner, will a certain ball speed at impact end up rolling out farther?

 

Yes. Backspin and skidding both have more friction than rolling friction during true roll, thus reduce energy and velocity. Rollout is greater, sometimes as much as 10%

 

There are other head design parameters, but I won't go into it here. You can PM if you'd like.

 

 

 

Cheers

Edited July 16, 2023 by Soloman1
deleted link to paper

[virtuoso]

3 minutes ago, Soloman1 said:

 

 

Yes. Backspin and skidding both have more friction than rolling friction during true roll, thus reduce energy and velocity. Rollout is greater, sometimes as much as 10%

 

There are other head design parameters, but I won't go into it here. You can PM if you'd like.

 

Here's a short paper on effect of skid distance, loft and roll ratio:

 

https://www.sciencedirect.com/science/article/pii/S1877705814006250

 

Cheers

Yes, agreed, thus, if one of my guys averages too much speed at the cup, and he already has the tour avg of 20 rpm of topspin, do I want to try to increase energy transfer or that topspin number?

[Soloman1]

too much speed?

[virtuoso]

5 minutes ago, Soloman1 said:

too much speed?

Yeah, poor capture speed…..as in, they tend to blow it past the hole.

[Soloman1]

I  get that, but why do you want to increase velocity at the hole?

[virtuoso]

6 minutes ago, Soloman1 said:

I  get that, but why do you want to increase velocity at the hole?

No, that’s my point. If he has bad speed control, ie, hits it too hard all the time, I’m not going to make it worse by changing his technique or changing his putter such that he gets better energy transfer or more topspin. I don’t want his ball getting into true roll sooner than it already is, because the ball will just roll out farther past the hole.

[Soloman1]

Well, as I said before, he can use a slower (or shorter), more controlled stroke.

[virtuoso]

3 minutes ago, Soloman1 said:

Well, as I said before, he can use a slower (or shorter), more controlled stroke.

Well sure, he’s a tour pro trying to run the ball 1 foot past instead of 2 feet past. I’d love for him to make a slower stroke, but I’m not going to deloft his putter and take him to 60 rpm of topspin and say, “Now hit it even softer!”

[Soloman1]

OK.

 

Papers with testing by putter design engineers about the effects of true roll distance and loft on distance control aren't something you're interested in. That's fine.

[virtuoso]

Based on your testing, what is the optimum launch angle for putting?

 

I’m just trying to figure out if you’re saying that laboratory conditions that produce max topspin and smash factor are what you are recommending for all on-course conditions.

 

Just to answer your other question, my functional launch parameters would be around 2 degrees of launch, 20 rpm of topspin is plenty, single digits on the side spin is preferred and I don’t care about smash as long as it is a pretty consistent strike, and the mis hit avg offsets the impact face angle avg. If you’re doing all that, you should look other places to tweak your putting.

Edited July 16, 2023 by virtuoso

[Soloman1]

4 hours ago, virtuoso said:

Based on your testing, what is the optimum launch angle for putting?

 

I’m just trying to figure out if you’re saying that laboratory conditions that produce max topspin and smash factor are what you are recommending for all on-course conditions.

 

Just to answer your other question, my functional launch parameters would be around 2 degrees of launch, 20 rpm of topspin is plenty, single digits on the side spin is preferred and I don’t care about smash as long as it is a pretty consistent strike, and the mis hit avg offsets the impact face angle avg. If you’re doing all that, you should look other places to tweak your putting.

 

For tour greens (11-13 stimp) some studies show <1 is optimum. I know many people say 1.5-2, but there is no evidence to support that with speed and conditioning of tour greens today. There is no depression to get the ball out of.

 

It’s not just my testing, but by others also.

 

I didn’t say to maximize forward spin. Forward spin reduces distance to true roll. Backspin does not. A shorter distance to true roll reduces the variance of greens on the putt. It’s been proven over and over.

 

I didn’t say testing is done in laboratory conditions. Of course I, and some others, test on grass. Not everyone is dumb.

 

Testing indoors is fine for face geometry, path, AoA, etc. Outdoors, dispersion shows the MOI of a putter on vertical and horizontal off-center strikes.

 

The comment that you don’t want to reduce putter loft and have someone swing slower is opposite to data that a loft of -1 with forward spin results in more consistent distance control.

 

The data has been around for a long time. 

 

Someone has to either rely on manipulating the stroke to achieve a desired strike geometry, or they can fold in putter design with stroke to increase consistency.

 

There are plenty of other things about putting, obviously. I’m not advancing my theory on putting. You are welcome to disregard everything I’ve said.

 

I’m only saying what I know from my testing and reading and talking to people in R&D of major manufacturers about putters and testing. I use different equipment to be sure results are consistent.

 

Companies don’t want to show testing of putters. Sites that say they test putters have no data, only anecdotal comments by people.

 

I’m always open to ideas backed by some evidence.

[virtuoso]

Ok, fair enough, it sounds like you’ve done your due diligence, but just so I understand: are you going for a 0 degree launch angle? And what topspin rate are you shooting for?

[Soloman1]

6 hours ago, virtuoso said:

Ok, fair enough, it sounds like you’ve done your due diligence, but just so I understand: are you going for a 0 degree launch angle? And what topspin rate are you shooting for?

 

I things I look for are strike to have some consistency center of face vertically and horizontally, very little to no rise through impact, face and path angles.

 

And distance to true roll about 10%.

 

I don’t chase rpm or launch angle. They are what they are, but will generally be very little backspin spin or forward spin of any number and launch angle generally will be under 1.5 when the things above are met.

 

Ball position ends up being back from starting position many times.

[virtuoso]

3 minutes ago, Soloman1 said:

 

I things I look for are strike to have some consistency center of face vertically and horizontally, very little to no rise through impact, face and path angles.

 

And distance to true roll about 10%.

 

I don’t chase rpm or launch angle. They are what they are, but will generally be very little backspin spin or forward spin of any number and launch angle generally will be under 1.5 when the things above are met.

 

Ball position ends up being back from starting position many times.

Ok, thanks Solomon, we differ a little bit in our approach but not that much.

[Soloman1]

In what way? I'm always open to listen to legitimate people. I consider you legit.

[virtuoso]

15 hours ago, Soloman1 said:

In what way? I'm always open to listen to legitimate people. I consider you legit.

I guess the main difference would be that all the guys that come into see me have a positive angle of attack. The left hand low guys are 1-2 degrees up and the right hand low guys are 2-4 degrees up. But, that does set the stage to set up a spin loft situation that allows them to generate a small lift of the ball at impact while inducing some amount of top spin. I wouldn't move the ball back and try to get their attack zero'd out because it would change their technique pretty radically, and the research I've seen shows that reducing the initial surface interaction at impact can improve consistency. One of my main jobs is to work with loft and head set up to try to get the spin loft number right based on their handle position, which varies across the spectrum, even for my tour players. I see lots of handle-back and handle-forward, but no downward or true level strikes. In 20 years I've probably only seen 2 tour players actually have a negative angle of attack--both of them bad putters.

Edited July 17, 2023 by virtuoso

[iacas]

5 hours ago, virtuoso said:

the research I've seen shows that reducing the initial surface interaction at impact can improve consistency

 

Yes.

 

Yes also to the negative AoA stuff.

 

It also makes sense that if you do happen to launch the ball lower (like, 0°), that because it's lower to and thus "rubbing" against the ground more and earlier, it will result in true roll earlier. But that isn't that important in putting, either, as long as the golfer is doing things pretty well.

Edited July 17, 2023 by iacas

[Soloman1]

5 hours ago, virtuoso said:

I guess the main difference would be that all the guys that come into see me have a positive angle of attack. The left hand low guys are 1-2 degrees up and the right hand low guys are 2-4 degrees up. But, that does set the stage to set up a spin loft situation that allows them to generate a small lift of the ball at impact while inducing some amount of top spin. I wouldn't move the ball back and try to get their attack zero'd out because it would change their technique pretty radically, and the research I've seen shows that reducing the initial surface interaction at impact can improve consistency. One of my main jobs is to work with loft and head set up to try to get the spin loft number right based on their handle position, which varies across the spectrum, even for my tour players. I see lots of handle-back and handle-forward, but no downward or true level strikes. In 20 years I've probably only seen 2 tour players actually have a negative angle of attack--both of them bad putters.

 

Yes, I understand not fiddling with tour guys much and matching hardware to them. Yep, almost everyone has + AoA. Maybe there's some confusion. I don't advocate a negative AoA at all. I don't know where that came from. Some studies show a putter with -1 static loft, with a + AoA results in tighter distance control than a higher lofted face with all other things being equal. I look to reduce initial bounce, get to skid and end-over-end faster and consistency.

 

When I say moving ball position, I'm talking from here |          | to there, maybe...