Putting, Forward Press

[kevin262]

Forward Press: is this the general idea?

• When you putt a golf ball with enough forward press, you're essentially delivering the putter face to the ball with some degree of negative loft.
• This negative loft causes the putter face to make contact with the ball at a point slightly above the equator of the ball.
• Contacting the ball above the equator causes the ball to roll forward with some amount of topspin, versus backspin.
• This topspin gives the ball a smoother "roll" towards the hole
• (As opposed to a putt that starts with back spin, where you get that herky-jerky period where friction catches and halts the backspin of the ball before it starts rolling with topspin).

Corollary Question: a forward-pressed golf putt and a "follow" shot in pool both create topspin via above-the-equator ball contact, correct?

 

 

[iacas]

You don't want to hit putt with negative loft. I prefer:

• 1-2° delivered loft
• 2-3° AoA

That creates a tiny bit of topspin. Negative loft would just drive the ball into the ground.

[Golfingdad]

To answer your first question, the main reason I do it is it's a good "trigger" with which to start my swing.  It does usually roll pretty well but I have no idea what the physics actually are - I've never been on a SAM machine.  @iacas gave you the scoop on the idea numbers above.

To answer your corollary question:  No.  The topspin in the pool shot isn't created by the location of the contact alone; it's created by the location combined with the angle the cue is arriving at.  (Think what would happen if you tilted the cue up really high and hit straight down into the table on the same spot.)  A putt is the same in that it has more variables besides location of the contact.

[kevin262]

1 hour ago, iacas said:

You don't want to hit putt with negative loft. I prefer:

• 1-2° delivered loft
• 2-3° AoA

That creates a tiny bit of topspin. Negative loft would just drive the ball into the ground.

So in that scenario, you'd be making contact slightly below the equator (b/c of the delivered loft), while coming in with an ascending strike. In addition to creating a tiny bit of topspin, that would also hit the ball forward and up off the ground, correct? At least for a moment.

Edited January 18, 2017 by kevin262

[kevin262]

1 hour ago, Golfingdad said:

To answer your first question, the main reason I do it is it's a good "trigger" with which to start my swing.  It does usually roll pretty well but I have no idea what the physics actually are - I've never been on a SAM machine.  @iacas gave you the scoop on the idea numbers above.

To answer your corollary question:  No.  The topspin in the pool shot isn't created by the location of the contact alone; it's created by the location combined with the angle the cue is arriving at.  (Think what would happen if you tilted the cue up really high and hit straight down into the table on the same spot.)  A putt is the same in that it has more variables besides location of the contact.

I don't play pool, but the pool instruction sites show that a basic follow shot (shot with top spin) is created by hitting the ball slightly above the equator (but not too high up). Assuming that the outside rail of the pool table is taller than the equator of a cue ball, you can only hit the ball with a decending angle -- which, granted, could be very shallow.

So if you putt a golf ball with a slightly delofted putter face (say, -3°), and the contact is one dimple or so above the equator, it would roll nicely, with top spin. 

That said, I'm sure if you keep delofting more and more you'd eventually reach a point where the ball would get trapped between the putter face and the grass, and skid or get dragged forward. 

[Golfingdad]

48 minutes ago, kevin262 said:

So if you putt a golf ball with a slightly delofted putter face (say, -3°), and the contact is one dimple or so above the equator, it would roll nicely, with top spin.

This still isn't factoring in the angle of attack.  To take it to the extreme, if I were to hover the putterhead directly above the back of the ball while leaning it forward so the face is angled down at 3 degrees and then just dropped it straight down, the ball would certainly not roll nicely with topspin.  It would likely have some backspin and then bounce up or do something else weird.

Now, I don't know the math too well (frankly, I've probably dug myself a hole with these posts as it is since I'm really not a numbers guy - in golf, I mean) but if you're delivering the head with -3 degrees of loft then you need to be attacking the ball on some kind of ascending blow to keep from driving it into the ground.

Not to mention, since putters usually have 3-5 degrees of loft on them, then you're talking about a heck of a forward press to get that putter to lean 3 degrees the other way. :)

(That might be a good shot for the old days of the stymie when you needed to jump another ball) 

[saevel25]

2 hours ago, kevin262 said:

So in that scenario, you'd be making contact slightly below the equator (b/c of the delivered loft), while coming in with an ascending strike. In addition to creating a tiny bit of topspin, that would also hit the ball forward and up off the ground, correct? At least for a moment.

If you were on a hard surface, maybe. The green is soft, and the ball tends to sit down a small bit. The small loft with a slight upward angle of attack gets the ball out of that depression it sits in. 

 

[kevin262]

13 hours ago, Golfingdad said:

...if you're delivering the head with -3 degrees of loft then you need to be attacking the ball on some kind of ascending blow to keep from driving it into the ground.

Not to mention, since putters usually have 3-5 degrees of loft on them, then you're talking about a heck of a forward press to get that putter to lean 3 degrees the other way. :)

Apparently some people that consciously putt with negative loft do try to use an ascending blow.  Not sure how exactly how they do that -- maybe by moving the ball up in their stance (towards the lead foot), so the putter has passed the low point in its arc and is back on the way up by the time it hits the ball?

On shaft lean - if you have a 35 inch long putter, with 3 degrees of loft, you'd need to press the butt end of the club forward 3.04" to get -2 degrees of loft.  You'd need 3.68" of forward press to get -3 degress of loft.  Doable.

@golfingdad @iacas Tell you what guys, try it out  -- roll some putts on a smooth carpet, using a lot of forward shaft lean (enough that the putter face is no longer visible from directly above).  Try to keep the putter head moving flat, so there isn't a lot of descending or ascending attack.  If you can line the balls w/ a marker, line up the mark so you can watch it roll.

Then roll some putts without the forward press.  My prediction -- you'll notice that the forward pressed putts (w/ negative loft) give a noticeably smoother roll.

That's just my prediction -- let me know what results you get!

 

[iacas]

11 minutes ago, kevin262 said:

@golfingdad @iacas Tell you what guys, try it out  -- roll some putts on a smooth carpet, using a lot of forward shaft lean (enough that the putter face is no longer visible from directly above).  Try to keep the putter head moving flat, so there isn't a lot of descending or ascending attack.  If you can line the balls w/ a marker, line up the mark so you can watch it roll.

Then roll some putts without the forward press.  My prediction -- you'll notice that the forward pressed putts (w/ negative loft) give a noticeably smoother roll.

@kevin262, I'm an instructor, and I've spent a lot of time studying and looking into this.

I fear that you're getting caught up a little bit in feels that may or may not align with reality. For example, with a ball forward enough, and a right-eye dominant right-handed putter, they can deliver 5 or 6° loft at impact but still not see any of the putter face at impact.

As I said, I prefer a little bit of positive loft (1-2°) with an AoA slightly higher than that (2-3°). That delivers enough loft to get the ball out of the small depression without lifting it too high in the air, and with just a little bit of forward spin (it's impossible to launch a ball with topspin like you can in pool).

[Golfingdad]

13 hours ago, Golfingdad said:

Not to mention, since putters usually have 3-5 degrees of loft on them, then you're talking about a heck of a forward press to get that putter to lean 3 degrees the other way. :)

 

18 minutes ago, kevin262 said:

On shaft lean - if you have a 35 inch long putter, with 3 degrees of loft, you'd need to press the butt end of the club forward 3.04" to get -2 degrees of loft.  You'd need 3.68" of forward press to get -3 degress of loft.  Doable.

@iacas knows what he's talking about in regards to golf, but as far as the math is concerned, just wanted to point out that you were right and I was wrong about this little bit of math.  I had a number in my head from a discussion elsewhere about the legality of Bryson DeChambeau's putter except those numbers are entirely different.  To top it off, I think I was even doing that wrong.

Good thing I'm an engineer by day so I don't have to worry about any of that pesky math stuff. 

[GolfLug]

100% agree with @iacas about the AoA and loft numbers (I have been on a SAM with him previously).

@kevin262, I think shaft lean is not simply a 'math' factor. In your case it might be allowing you to get in a better physical position to make a better stroke with a + or atleast level AoA vs. back lean. An individual thing. I have actually consciously gotten away from shaft lean as it caused my putts to skip and check in the first couple of feet instead of roll.

[kevin262]

@GolfLug Interesting.  When the ball was skipping/checking up, were you coming down on the ball?  Was the ball positioned in the middle of your stance, or even further back, so the putter was making contact with the ball before it bottomed out (before the lowest point in the arc)?

It almost sounds like a stop shot in pool, but hit with too much of a downward angle

http://billiards.colostate.edu/high_speed_videos/HSV3-1.htm

http://www.easypooltutor.com/articles/30-shotmaking-basics/44-stop-shot.html

[iacas]

The pool analogies aren't really working. You can hit the top of the cue ball above the equator and still generate backspin.

[kevin262]

@iacas If you want to increase your angle of attack when putting, so you're hitting more up on the ball, is it best to do that by moving the ball position left, further down the aim line?

[Hatchman]

Left or right handed?

[kevin262]

7 minutes ago, Hatchman said:

Left or rigvht handed?

Right handed

[iacas]

2 hours ago, kevin262 said:

@iacas If you want to increase your angle of attack when putting, so you're hitting more up on the ball, is it best to do that by moving the ball position left, further down the aim line?

To a point. Any more than a few inches forward of center is too much, typically.

[GolfLug]

3 hours ago, kevin262 said:

@GolfLug Interesting.  When the ball was skipping/checking up, were you coming down on the ball?  Was the ball positioned in the middle of your stance, or even further back, so the putter was making contact with the ball before it bottomed out (before the lowest point in the arc)?

It almost sounds like a stop shot in pool, but hit with too much of a downward angle

http://billiards.colostate.edu/high_speed_videos/HSV3-1.htm

http://www.easypooltutor.com/articles/30-shotmaking-basics/44-stop-shot.html

Pretty sure coming down. But that's not the point. The point is 'forward press' benefit is not universal. For example, putting up in stance may help but then I may get 'too behind' the ball to hit up. Who knows what other 'tendencies' come in play that start affecting. Yeah you can certainly adapt to anything if you want to over time. I would rather get a putter fit to my existing stroke (I am planning to do so this summer) and ball positioning. It's easier and my time would be better spent learning to hit up on a driver instead. But then that's just me..