My Study of OBFL versus NBFL

[sev112]

And if you want to practise OBFL and NBFL to make your own mind up you can do this with a putter, because exactly teh same argument has been going on in putting theory for decades - is putter swing path more important than face angle ?

Get a putter and some balls and see what happens to balls when you approach them from inside, from outside, straight, with open, closed and neutral face angles to those paths.
Then make up your own mind.

However ...(he he he) this is the interesting bit, when face inserts get involved. Because you can get the same Gear Effect with putters. It is quite easy to impart side spin to a putt, particularly with a saoft insert or a coarse milled face, or with one of those NIKE Method or Yes putters with non-horizontal grooves. Because of the Gear Effect an impact closer to the Toe of the putter will create a draw spin taking teh putt right to left (and similarly for one close to the toe). This is less so for face balanced putters but does still apply)

So you can also decide after doing that experiment and various balls whether you want a soft face insert/groooved putter or a hard faced one. And that's a further discussion - ho ho

 

[Deleted Member 1156]

Anyone got an email address for Jack Nicklaus so I can inform him he spent his entire career hitting the ball incorrectly?

 

[AmandaJR]

Amanda, imagine this
You are about to hit a shot into a green with a greenside bunker and you want to fade/draw the ball into the flag.
Old BFL
Aim your body at the bunker and point your clubface at the flag.
The old laws said the ball will start where you are aiming your body and swing and will finish where your clubface is pointing (the flag)
We now know that is wrong.
NBL
Aim your body at the bunker but point your clubface IN BETWEEN the bunker and the flag. The ball will start where your clubface is pointing and your swing will fade/draw the ball back to the flag.

Ok now that is making sense and is easy to remember. But....what is my swing doing through this? Am I manipulating that or is the club face angle together with a normal swing creating the shot shape?

 

[Region3]

Anyone got an email address for Jack Nicklaus so I can inform him he spent his entire career hitting the ball incorrectly?

I don't understand what you're trying to say D4S. (Unless you're fishing and I've just bitten?)

Are you saying that the players hitting the shots are correct rather than the LM's and HS cameras?

I believe that's what they think they're doing, but science says that they can't be doing what they think they are.

 

[bobmac]

Ok now that is making sense and is easy to remember. But....what is my swing doing through this? Am I manipulating that or is the club face angle together with a normal swing creating the shot shape?

Because your swing is going one way and your clubface is pointing another way, that will be sufficient to shape the ball for you.....if your swing is straight. If not, you may need to experiment to get it right.
For example, if your normal swing path is out to in, you may not need to aim left at all as your swingpath is allready going towards the bunker

 

[AmandaJR]

Because your swing is going one way and your clubface is pointing another way, that will be sufficient to shape the ball for you.....if your swing is straight. If not, you may need to experiment to get it right.
For example, if your normal swing path is out to in, you may not need to aim left at all as your swingpath is allready going towards the bunker

Ok that makes sense to me. Swing path is definitely inside the line on the downswing and my normal iron shape is straight or a soft draw unless I close the club face at impact!!

 

[Region3]

Ok, I'll bite again, just to keep you entertained though you understand.

Different balls, different results.​

Balls.
A billiard ball and brussell sprout, yes, but golf balls no (or not enough to notice)

I'm not sure, but it might be an interesting reasson why the OBF"L"s used to be "right" and the NBF"L"s might now be "right!"

Plenty of players have played the shots the same way through the ball changes. Maybe (just maybe) they're not doing what they think they are?

DB wraps his foot around the ball

<lost for words></lost for words>

It is called "Gear Effect" and club makers have known about it for greater than 100 years

Gear effect only applies to clubs with the centre of gravity significantly behind the impact point. It doesn't happen with irons.
I'd argue that even on the biggest mallet on the longest putt it's so small as to be insignificant with putters as well.

Get a putter and some balls and see what happens to balls when you approach them from inside, from outside, straight, with open, closed and neutral face angles to those paths.
Then make up your own mind.

Try this with a putter.

Put a ball about 2' from the hole on a flat line and address it with the putter face pointing 45° to the right of the hole.

Use any swing path you like and come and tell us the old laws are correct when you've holed one.​

 

[Deleted Member 1156]

I don't understand what you're trying to say D4S. (Unless you're fishing and I've just bitten?)

Are you saying that the players hitting the shots are correct rather than the LM's and HS cameras?

I believe that's what they think they're doing, but science says that they can't be doing what they think they are.

No, certainly not trying to get anyone to bite or wind anyone up.

My point is quite simply this....

For years golfers have been able to line up their clubface and swingpath to hit a specific shape of shot or hit the ball to a specific target. We now have high speed cameras and slowmo and suddenly someone decides that we have all been doing it wrong.

Well sorry but the next time I fade or draw my ball to 12 inches from the flag from 150 yards out, try convincing me that I've been doing it wrong. I've been playing this game for 40 years. Hitting a draw/fade/slice/hook/push/pull or any other shot is exactly the same now as it's always been.

 

[USER1999]

Well sorry but the next time I fade or draw my ball to 12 inches from the flag from 150 yards out, try convincing me that I've been doing it wrong. I've been playing this game for 40 years. Hitting a draw/fade/slice/hook/push/pull or any other shot is exactly the same now as it's always been.

Of course it hasn't changed. That would be impossible.

What has changed is our understanding of how it happens.

 

[bobmac]

suddenly someone decides that we have all been doing it wrong.

If you fade or draw the ball onto your target, you're not doing it wrong.
However, you may not be doing what you think you are doing.
I'll give you an example.....
You may aim your body at the left hand bunker and think your clubface is pointing at the flag but it may only be pointing half way to the flag

 

[Deleted Member 1156]

Of course it hasn't changed. That would be impossible.

What has changed is our understanding of how it happens.

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.

 

[One Planer]

My point all along has been that the laws of physics CANNOT change.

... But peoples' understanding can!

 

[sev112]

Balls.
A billiard ball and brussell sprout, yes, but golf balls no (or not enough to notice)

Gear effect only applies to clubs with the centre of gravity significantly behind the impact point. It doesn't happen with irons.



Try this with a putter.

Put a ball about 2' from the hole on a flat line and address it with the putter face pointing 45° to the right of the hole.

Use any swing path you like and come and tell us the old laws are correct when you've holed one.[/COLOR][/LEFT]

Fair point on the Gear Effect and CoG - it doesnt disappear it is just less pronounced, but i will grant you that.


Just did your test
- you are right i couldnt sink any 2' putts at 45 degrees
- but i did sink all ofteh 10 degrees, most of the 20 degrees and only some of the 30 degrees ones

Which again suggests that teh ball starts somewhere in between the face angle and the clubhead path. So somewhere in between OBFL and NBFL. and closer to NBFL face angle

But this is nothing new - i have just picked up my 1968 copy of the Gofl Society of Great Britain's "Search for the perfect swing" and it states "a ball will always leave a clubface somewhere between these 2 directions, but usually nearer the direction alongwhcih the clubface is pointing"

my point (overall) being that the "laws" are too simplistic to define exactly what happens

 

[Imurg]

"laws" are too simplistic

So they get more complicated...?
God help us.......

 

[Val]

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.

:clap:

If you can hit a draw or fade and know how you are doing it do you really NEED to understand how it's happening?

I put my foot on the clutch of my car and move from 1st to 2nd gear, I couldn't give a monkeys how it happens as long as it does.

 

[sev112]

Of course it hasn't changed. That would be impossible.

What has changed is our understanding of how it happens.

Whilst i agree in principle, in fact "it" has happened several times in golf history.

We no longer use hickory shafts, and we no longer use gutta percha balls, etc etc
People played different shots with different swings with different equipment. And manufacturers developed materials and products, and then golfers learned to play new shots that exploited them

But that's just me being argumentative for the sake of it

 

[Region3]

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.

One final question.

Imagine you have a 12yr old son (you might have, I don't know), and you are out playing golf with him.

His drive lands in the right hand rough about 6' behind a foot wide tree trunk and he has to fade the ball around it. It is going to hurt if it goes wrong.

You line his feet up left of the target (as both 'laws' agree), do you tell him to line his club up at the tree or to the left of it?

 

[Val]

One final question.

Imagine you have a 12yr old son (you might have, I don't know), and you are out playing golf with him.

His drive lands in the right hand rough about 6' behind a foot wide tree trunk and he has to fade the ball around it. It is going to hurt if it goes wrong.

You line his feet up left of the target (as both 'laws' agree), do you tell him to line his club up at the tree or to the left of it?

Id tell him to chip out

 

[sev112]

One final question.

Imagine you have a 12yr old son (you might have, I don't know), and you are out playing golf with him.

His drive lands in the right hand rough about 6' behind a foot wide tree trunk and he has to fade the ball around it. It is going to hurt if it goes wrong.

You line his feet up left of the target (as both 'laws' agree), do you tell him to line his club up at the tree or to the left of it?

I would tell him to aim his club face exactly 22.5% of the distance between his feet line and the tree/hole he he

Really i would tell him to chip out sideways
Or give himself a margin of safety from the tree because none of us can line ourselves up accurately enough

 

[JustOne]

Here's my take

some think the OBFLs are "laws"
something the NBFLs are "laws"
some think the D-plan is a "Law"

None of them are Laws (of Physics) - and this is because they all have in-built simplifying assumptions, e.g. on physical interaction of club and ball - and the OBFL's simplifying assumption is different from the NBFL's simplifying assumption, and it is why both are valid. Also the D-plane is valid, but it too contains an assumption about interaction of club and ball.

Most people presume (in these and similar debates elsewhere) that the impact between clubhead and ball is perfectly elastic and perfectly rigid (coefficient of restitution -1). i think the NBFLs theoretically assume this, wheras the OBFLs are based on physical observation.
Lets imagine 2 extreme impacts - 1) a cast golf club hitting a billiard ball, and 2) a (forged?) golf club hitting a golf ball sized piece of dog pooh. Both are hit with an open face on a straight clubhead path - the billiard ball will start off in the direction of the face, and the "pooh" ball will start off in the direction of the swing plane. Reality (i.e. the plastic compressing inefficient impact of a real club on a real ball) is somewhere between the 2, and will depend on the nature of the golf ball and the golf club. Different balls, different results.

Perhasps (and i dont know whether this is the case) in the older days of forged clubs and soft balata balls, they started off more dominated by clubhead path; maybe today with springy clubs and balls designed to spin less and penetrate more, they start off closer to the face angle ? I'm not sure, but it might be an interesting reasson why the OBF"L"s used to be "right" and the NBF"L"s might now be "right!"

So you are all both right and all both wrong (also the D-plan guy)

Try and explain OBFLs and NBFLs to David Beckham and Christiano Ronaldo. DB wraps his foot around the ball to spread the area of impact and get good frictional contact to impart spin. CR hits the ball with the (small area) toe of his boot, accordnigly deforms the football into an odd shape and then relies on the aerodynamic instability that causes the ball to wobble in flight. Impact conditions are key here.

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".

And if you want to practise OBFL and NBFL to make your own mind up you can do this with a putter, because exactly teh same argument has been going on in putting theory for decades - is putter swing path more important than face angle ?

Get a putter and some balls and see what happens to balls when you approach them from inside, from outside, straight, with open, closed and neutral face angles to those paths.
Then make up your own mind.

However ...(he he he) this is the interesting bit, when face inserts get involved. Because you can get the same Gear Effect with putters. It is quite easy to impart side spin to a putt, particularly with a saoft insert or a coarse milled face, or with one of those NIKE Method or Yes putters with non-horizontal grooves. Because of the Gear Effect an impact closer to the Toe of the putter will create a draw spin taking teh putt right to left (and similarly for one close to the toe). This is less so for face balanced putters but does still apply)

So you can also decide after doing that experiment and various balls whether you want a soft face insert/groooved putter or a hard faced one. And that's a further discussion - ho ho

Holy cow Sev! I bow to your posting prowess!!

.....however the ballflight laws are calculated assuming a centered strike off the sweetspot ..... so your point (whatever it was)....is moot!

:rofl: