My Study of OBFL versus NBFL

[sev112]

Actually i've just spend half an hour doing that putting exercise i mentioned and it does work out about 25% of the difference in angle between club path and face angle. (i.e. the ball starts off closer to the face angle than the clubhead path

 

[JustOne]

EXACTLY!!!

Which means there are no NEW or OLD laws. Just because we have a different understanding of something doesn't mean that it has changed. My point all along has been that the laws of physics CANNOT change.

Did someone say physics had changed? I think you're out of your league when it comes to understanding some basic concepts... such as cause and effect.

 

[Val]

Did someone say physics had changed? I think you're out of your league when it comes to understanding some basic concepts... such as cause and effect.

JO I think we would all accept you are pretty knowledgeable on the subject but that comment is rude to say D4S is out his depth.

D4S has stripped the basics back by saying people are still doing now what they did years ago when swinging the club to shape the ball, laws haven't changed it's peoples understanding that may have changed hence all these new graphs etc. If I can hit a draw or fade without thinking about it too much and get the desired result I wouldnt care too much how it happened.

Remember the post and video im sure you put up about Luke Donald using old ball flight laws? He knew what he needed to do and executed the shot, im sure he won't really care about which laws he thought he followed.

 

[JustOne]

D4S has stripped the basics back by saying people are still doing now what they did years ago when swinging the club to shape the ball,

When it comes to teaching it's not good enough to say "Do what D4S does" when he doesn't even know what he does himself.

When Bobmac sells a V-Easy does it come with the putting instructions: "Just hit it in the hole, D4S does, physics hasn't changed!"

.... OR is there a correct way?

 

[SocketRocket]

And here's one that no-one has flagged up yet.
It is related to the impact conditions post above.

Neither the OBFLs nor NBFLs consider what the face of the club is doing DURING impact - i.e. whether the face is closing or opening through impact.

We know from photography (and physics) and the ball manufacturers and club manufacturers' blurb, that the ball is compressed on impact and stays on the face for a finite period of time

During that time, a closing or opening face will impart spin to the ball. It is called "Gear Effect" and club makers have known about it for greater than 100 years - it is why the face of woods/long irons are curved in plan.

Oddly however a "closing" face generates Fade/Slice spin, and an "Opening" face generates drawspin !!!!

You can try this :
Put a putter right up against a ball on a smooth surface (wood floors are good for this), and (without taking the putter back or away from the ball) just rotate its face with your fingers. An anti-clockwise rotation (closing face) will spin the ball off the the right (fade) and a clockwise rotation (opening face) will spin the ball off the the left (draw spin).

This is another reason why neither the OBFL nor the NBFL are actually a "Law".

The ball sits on the clubface for around six milliseconds at impact. This has been proven by high speed cameras. How can an opening or closing clubface affect the impact conditions in this period of time. It cannot. It is the way the clubface is cutting across the ball at this exact moment that creates the balls axis of rotation.

Gear effect is a result of clubhead deflection and is amplified by clubfaces with a curved surface. it is nothing to do with whether the clubface is opening or closing at the moment of impact.

Regarding the putter face: The ball will leave the face mainly in the direction that the clubface points with a very small influence of the swingpath. Its exactly what the NBFL say it will do. AND, yes it is a law, a law of physics, its part of ballistic science.

 

[sev112]

The ball sits on the clubface for around six milliseconds at impact. This has been proven by high speed cameras. How can an opening or closing clubface affect the impact conditions in this period of time. It cannot. It is the way the clubface is cutting across the ball at this exact moment that creates the balls axis of rotation.

Gear effect is a result of clubhead deflection and is amplified by clubfaces with a curved surface. it is nothing to do with whether the clubface is opening or closing at the moment of impact.

Regarding the putter face: The ball will leave the face mainly in the direction that the clubface points with a very small influence of the swingpath. Its exactly what the NBFL say it will do. AND, yes it is a law, a law of physics, its part of ballistic science.

Presumption
Presumption
Presumption

nice science

 

[JustOne]

Presumption
Presumption
Presumption

nice science

Are we back to the OLD ballflight laws now?

 

[SocketRocket]

Presumption
Presumption
Presumption

nice science

No presumption at all.

If you wish a grown up debate on the subject then present me with your arguments in detail and I will address them for you.

 

[Val]

When it comes to teaching it's not good enough to say "Do what D4S does" when he doesn't even know what he does himself.

When Bobmac sells a V-Easy does it come with the putting instructions: "Just hit it in the hole, D4S does, physics hasn't changed!"

.... OR is there a correct way?

That is a fair comment on teaching but again thats all in the concept of understanding how it happens which is what a teacher does.

If 2 players do the same thing and hit the same shot and 1 knows how it happens and 1 cant explain it does that make 1 shot right and 1 shot wrong?

 

[JustOne]

If 2 players do the same thing and hit the same shot and 1 knows how it happens and 1 cant explain it does that make 1 shot right and 1 shot wrong?

If one player stands on his hands and gets the ball in the hole should we teach that?

In terms of instruction it would be far easier if we all sang from the same hymn sheet... or at least from the same book!

 

[sev112]

Table tennis
Face angle usually very skew to bat path
Ball foolows much closer to bat path than face angle
Take the rubber off teh bat and play with a wooden bat and the ball leaves the bat much closer to the bat face angle.

It's all to do with collision conditions

Billairds/snooker/pool
Put chalk on a snooker cue and you can hit teh cue ball very off centre (i.e. large face angle) and make the cue ball still go in teh direction of the cue. Have no chalk on a pub pool cue with a hard wooden tip and the same shot will send the ball off at the highly skew "face angle" *i.e. the line between the contact point on teh surface of the ball and the centre of the ball"

i am sure the laws of physics still apply to those 4 cases

 

[Foxholer]

The ball sits on the clubface for around six milliseconds at impact. This has been proven by high speed cameras. How can an opening or closing clubface affect the impact conditions in this period of time. It cannot. It is the way the clubface is cutting across the ball at this exact moment that creates the balls axis of rotation.

Actually, it can.

But the effect is insignificant in relation to the effect of the club-face cutting across the ball - for this period.

Spin imparted depends on the time that the two entities are actually touching. That's why Molitors and other rocks spin less - they are in contact with the club-face for a shorter period of time.

 

[JustOne]

Table tennis
Face angle usually very skew to bat path
Ball foolows much closer to bat path than face angle
Take the rubber off teh bat and play with a wooden bat and the ball leaves the bat much closer to the bat face angle.

It's all to do with collision conditions

Billairds/snooker/pool
Put chalk on a snooker cue and you can hit teh cue ball very off centre (i.e. large face angle) and make the cue ball still go in teh direction of the cue. Have no chalk on a pub pool cue with a hard wooden tip and the same shot will send the ball off at the highly skew "face angle" *i.e. the line between the contact point on teh surface of the ball and the centre of the ball"

i am sure the laws of physics still apply to those 4 cases

I don't think friction is applied after the ballflight laws.. the laws are there because of it. Each impact has it's own friction circumstances and each object ball has it's own compression/friction/weight properties etc, so comparing to a different ball/impact situation is like comparing Mars bars to Snickers.

I'm sure the impact/ballflight laws for tennis would be more like 60/40 face to path than the 85/15 for golf.

 

[Patrick57]

If you are just a wind up then don't bother answering. If you honestly want to learn something then make an effort to listen to people that understand the subject

The 'D' Plane is not just a subject that is of interest to Scientists, it is the truth of what creates side spin on a golf ball. It's not too difficult to understand and if you look up the subject on UTube then you will find many many Vids explaining it. If you cant be bothered then dont keep arguing a subject that you are ignorant of and one that you started the thread by asking others for advice.

I studied D-Plane and it all went a little over my head. Striking the ball on the downswing causes a 1-2° kick to the right and there's even a scale that allows you to work out this effect. Add this to the calculations needed for face and path angles for the ball flight.

I get my golf calculator out to work out what's supposed to happen and my buddies always interupt me and tell me to get on. with it

The OBFL stated that you should aim the clubface to the point you wish the ball to finish on and swing the club in the direction you want the ball to start on. THIS IS WRONG, IT WILL NOT WORK.

The old ball flight laws don't portray these instructions. I think you have been listening to someone who states the OBFL incorrectly.

NOW!!! If you wont read up on the 'D' Plane then you will not understand how this works and will be arguing from a position of ignorance.

Do you want to understand the subject or just make an argument based on your personal prejudices.

I think the OP made constructive statements that haven't yet been specifically challenged by anyone. All I hear is the old is completely wrong and the new is right. I say they are only a little more accurate, Kelley wasn't far off the mark you know.

 

[Patrick57]

Amanda.

Target at 12 o'clock blocked by tree. Swing at 2 (or 10) with club-face pointing at 1 (or 11 resp).

Best and simplest explanation I have ever heard. So why confuse issues with the new complicating parameters and tell everyone that the old style teachers were and are idiots.

Amanda.

Old laws would have you aiming the clubface at 12 in both cases - and ball would hit the tree (unless an unconscious adjustment is made)

I have never hit the tree using the old laws and I know thousands of people who manage this task using the same. I bet you would say Trackman and D-plane would have helped Beckham bend balls. Hey we've got a free kick, lets get the calculator out.

 

[JustOne]

Swinging down is 1 degree right with every degree down, assuming the shaft is on a 45 degree plane... which happens to change club by club.

here's a vid....

[video=youtube;N8WdW_kCjXQ]http://www.youtube.com/watch?v=N8WdW_kCjXQ[/video]



You still have to swing the club though! ....

 

[SocketRocket]

Actually, it can.

But the effect is insignificant in relation to the effect of the club-face cutting across the ball - for this period.

Spin imparted depends on the time that the two entities are actually touching. That's why Molitors and other rocks spin less - they are in contact with the club-face for a shorter period of time.

Well we will just have to disagree on the rotating clubface at impact. I didnt see any specific evidence to suggest this when I was studying the ballistics of golf ball impact. I would be interested in looking at any data that shows this to be the case though.

I do agree that the elasticity of the ball affects spin rates due to the way it deforms, compresses onto the clubface, then springs off (Coefficient Of Restitution) The ball in it's compressed state starts sliding up the face due to club loft and the force vector giving it no where else to go. This sliding is what generates spin. Where the ball is struck with an acute force it is this deflection that tips the axis of rotation such that sidespin is created.

 

[Patrick57]

It is of course impotant the coach knows the new laws inside out in case the student wants to know more but the majority dont.
K I S S

You're dead right.

I know the new laws inside out and have yet to get past using old directives. I use -3 to +3 path parameters and -3 to +3 face parameters. A bit like the clock parametres in an earlier post.

 

[Patrick57]

Simple, the ball goes where I want it to go. regardless of which physical law it used to get there.

I can't argue with that. A simple explanation of how you achieve this may be helpful for the other posters.

 

[JustOne]

You're dead right.

I know the new laws inside out and have yet to get past using old directives. I use -3 to +3 path parameters and -3 to +3 face parameters. A bit like the clock parametres in an earlier post.

You're teaching a student who is hitting draw shots and he says..

"I'd like to start the ball 5yds further to the right"

what do you tell him?