Something Your Teacher Can Teach You...

skipbales

AzB Silver Member
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The cue ball rarely leaves the tip with overspin. That is difficult to accomplish and dangerous. If you meant something else, it was not clear from your statement. Please clarify.

A lot of people, including some top instructors believe this happens, in spite of the slow motion video evidence that disputes it. I have heard Jerry Briesath and Bert Kinister refer to "overspin" as the cue ball front spinning faster then the ball is rolling. MANY people believe the ball overspins its way down the table and never catches up. The slow motion video shows the ball just rolls faster and any small amount of cue tip induced overspin that might exist is converted to forward roll almost immediately but people don't believe that.

They overstate the effect of "high action" on the cue ball.

The slow motion videos show that is not what is actually happening and it isn't until the cue ball impacts something and lifts its weight off the table that it actually spins faster than its forward motion and that is because it is in the air with no friction. It might be able to over spin on ice or something but not much on a cloth table.

I would defer to you, as an authority on this and know you have tested it. Is my understanding accurate? BTW my intention is to improve my own understanding, not to debate the issue with anyone's personal belief. I would just like to get your opinion on my own understanding. One thing I am sure of, having a perfect technical understanding of the physics doesn't make a person a great pool player. I just "strive to be technically correct" in all areas of my life.
 
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Bobkitty

I said: "Here kitty, kitty". Got this frown.
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A lot of people, including some top instructors believe this happens, in spite of the slow motion video evidence that disputes it. I have heard Jerry Briesath and Bert Kinister refer to "overspin" as the cue ball front spinning faster then the ball is rolling. MANY people believe the ball overspins its way down the table and never catches up. The slow motion video shows the ball just rolls faster and any small amount of cue tip induced overspin that might exist is converted to forward roll almost immediately but people don't believe that.

They overstate the effect of "high action" on the cue ball.

The slow motion videos show that is not what is actually happening and it isn't until the cue ball impacts something and lifts its weight off the table that it actually spins faster than its forward motion and that is because it is in the air with no friction. It might be able to over spin on ice or something but not much on a cloth table.

I would defer to you, as an authority on this and know you have tested it. Is my understanding accurate? BTW my intention is to improve my own understanding, not to debate the issue with anyone's personal belief. I would just like to get your opinion on my own understanding. One thing I am sure of, having a perfect technical understanding of the physics doesn't make a person a great pool player. I just "strive to be technically correct" in all areas of my life.

I do believe that hitting the OB directly head on, the two balls of equal weight come to a stop. The energy goes over to the OB and it heads out. If the CB has "over spin", it will continue on like tires peeling and head toward the OB. If it is sliding, it will stop, if it has reverse, it will draw backwards. Where am I wrong?
 

FranCrimi

AzB Silver Member
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How about we all get on the same page in defining the term 'force follow.'

Bob Jewett, can you define the term for us please? Thanks!
 

FranCrimi

AzB Silver Member
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Fran.. IMO force follow is actually demonstrated at 5:40 in the above video... It could be that Bob Jewett would give us a better explanation.
.

So are you saying that the definition of a force follow shot is any shot in which overspin occurs? I'm wondering if there are any other conditions that must occur in order for the shot to be classified as force follow. Would you happen to know?
 

skipbales

AzB Silver Member
Silver Member
I do believe that hitting the OB directly head on, the two balls of equal weight come to a stop. The energy goes over to the OB and it heads out. If the CB has "over spin", it will continue on like tires peeling and head toward the OB. If it is sliding, it will stop, if it has reverse, it will draw backwards. Where am I wrong?

It is not that you are wrong. That is what happens. As I understand it, it is the idea the reason the ball moves forward is it is"over spinning" as opposed to just forward rolling. A sliding cue ball stops. A back spinning cue ball backs up if it has back spin left after the collision. But a forward rolling cue ball is not spinning faster then it can roll, trying to get traction, it is just rotating forward.

I know it seems like it but I believe that is what the issue is. It is turning forward like a back spinning ball is turning back ward. The difference is the back spin is slipping and unable to make the ball go backwards until it hits something. The forward spin just makes the ball roll faster in the same way the back spinning ball slows the forward roll speed. The more spin the faster the roll. It is simply rolling, not sliding or back spinning or front spinning. A rolling cue ball can have degrees of roll, partial or full. At full roll it "wants" to continue rolling and a collision with a single ball of the same weight is not enough to stop it. It hits, lifts from the cloth a fraction, or sometimes a lot, and continues to "roll" (rotate). When it re-connects with the cloth it gets traction and goes forward. It is simply pushing the object ball out of its way.

It is semantics and the only difference is: Is the ball spinning along the cloth at whatever speed it is rolling, or is it spinning faster than it is rolling (over spin). From a pool players point of view it makes absolutely no difference. Who cares what someone calls it if they know what to expect? From an engineer's point of view, my understanding is, it is a technical mistake to say the ball is spinning faster than it is rolling.

I am not an expert and could be totally wrong. I have just seen the studies on this and hope Bob will take a moment to help us sort it out.

This is how Dr. Dave explains it:
Also, NV B.36 shows a simple experiment to show how difficult it is to achieve overspin without miscuing.

Now, after a CB hits an OB, it can most certainly have overspin. For example, in HSV 4.3 and NV 4.8 the CB has topspin. Before it hits the OB, the amount of topspin is the natural rolling amount (i.e., there is no "overspin"). After the CB hits the OB, the CB has more topspin than the natural rolling amount (i.e., there is "overspin"). This is what causes the CB to "follow" the OB to the rail. After rebound off the rail, some of the spin is retained (which looks like bottom spin now) causing the CB to draw back to the rail.

Note before the collision there is no overspin. The overspin results in the attempt to stop the forward progress of the rolling ball. The overspin is a result of the collision. The ball isn't spinning faster, it just isn't going forward any more and "wants" to continue.
 
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skipbales

AzB Silver Member
Silver Member
So are you saying that the definition of a force follow shot is any shot in which overspin occurs? I'm wondering if there are any other conditions that must occur in order for the shot to be classified as force follow. Would you happen to know?

My understanding of Force Follow is hitting as high on the cue ball as possible to give it immediate forward roll, not necessarily any overspin. It is an attempt to eliminate the sliding segment which precedes roll and get the cue ball into full roll immediately.

Dr. Dave writes

What is force follow, and how and when is it used?

A force follow shot is a follow shot hit with maximum topspin and fast speed. This term is used mostly when referring to a nearly straight-in (small cut angle) follow shot.

He doesn't mention overspin in conjunction with Force Follow but he clearly says overspin is possible, just not much and not for long.

What is your understanding of Force Follow?
 
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BC21

https://www.playpoolbetter.com
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It seems that "force" follow is pretty straightforward. Look at a straight-in shot, a full-ball hit, for example. When a rolling CB strikes the OB, its momentum is transferred to the OB, but inertia keeps the CB rolling, causing it to continue to follow it's normal path until eventually coming to a stop within a few inches, or within a couple of feet depending on initial speed. On a stun shot there is no rolling CB movement, and once the CB's momentum is transferred to the OB at impact, the cue ball stops dead. So that's the two natural CB options -- stop or roll forward.

If a forward-spinning CB strikes the OB, the momentum transfers from CB to OB as typical, but then the energy of that torqued CB kicks in and "forces" it forward. It's not rolling forward due to its inertia. It's the additional force/torque (top spin) that causes it to continue along its path, forcing it forward. A draw shot is the same thing -- a forced action in reverse direction. If the CB strikes the OB with enough forward spin or backward spin to force/propel it forward or backward after hitting the OB, it's a "forced" shot. The CB is forced to move and then begins to roll, and its inertia keeps it rolling until the friction of the cloth finally stops it.
 

bbb

AzB Gold Member
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i am not an instructor
but to me "force follow"
is when instead of rolling the cue ball has enough follow to "down shift" and turbo charge forward
ie "bend" or :"duck" from its path
ie go along the tangent line some and then go forward as opposed to the "peace sign where a rolling ball (ie must have follow on it) takes the 30 degree path
i assume dennis is reffering to shots where when the bend occurs can be controlled
 

Bob Jewett

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How about we all get on the same page in defining the term 'force follow.'

Bob Jewett, can you define the term for us please? Thanks!

When I was first learning about power strokes, force follow for me was only when the balls were close as with a fouette. Similarly, back then a "force draw" shot was a fouette draw shot.

I think the usage now is for any power follow shot where the cue ball gets most of its energy from the follow and it's with a fair amount of power.

I suppose a good example would be a side-of-the-rack break at 14.1 where the cue ball follows into and through the rack. That is not usually a full hit on the object ball but the energy from the follow is an important part of the shot.

A bad example is when you just follow a ball six diamonds down to the other end of the table. That's not a special power shot in my view.
 

FranCrimi

AzB Silver Member
Silver Member
When I was first learning about power strokes, force follow for me was only when the balls were close as with a fouette. Similarly, back then a "force draw" shot was a fouette draw shot.

I think the usage now is for any power follow shot where the cue ball gets most of its energy from the follow and it's with a fair amount of power.

I suppose a good example would be a side-of-the-rack break at 14.1 where the cue ball follows into and through the rack. That is not usually a full hit on the object ball but the energy from the follow is an important part of the shot.

A bad example is when you just follow a ball six diamonds down to the other end of the table. That's not a special power shot in my view.


That's how I see it too. I see it as a two-part shot where in the first part, the cue ball is sliding forward while it's rotating ---- the rotations acting like a buzz saw as it forces through the rack, and then once it stops sliding, the high level of rotations kick in and you get a second thrust that continues to drive it through the rack.

But I always see that pronounced second thrust with a force follow shot. Part one is the force and part two is the follow.
 

bbb

AzB Gold Member
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That's how I see it too. I see it as a two-part shot where in the first part, the cue ball is sliding forward while it's rotating ---- the rotations acting like a buzz saw as it forces through the rack, and then once it stops sliding, the high level of rotations kick in and you get a second thrust that continues to drive it through the rack.

But I always see that pronounced second thrust with a force follow shot. Part one is the force and part two is the follow.
thats a great definition fran
 

BC21

https://www.playpoolbetter.com
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When I was first learning about power strokes, force follow for me was only when the balls were close as with a fouette. Similarly, back then a "force draw" shot was a fouette draw shot.

I think the usage now is for any power follow shot where the cue ball gets most of its energy from the follow and it's with a fair amount of power.

I suppose a good example would be a side-of-the-rack break at 14.1 where the cue ball follows into and through the rack. That is not usually a full hit on the object ball but the energy from the follow is an important part of the shot.

A bad example is when you just follow a ball six diamonds down to the other end of the table. That's not a special power shot in my view.

Ok...this all makes sense. So is there an official definition of FORCE FOLLOW?

With the correct speed, one could send the CB following the OB a distance of six diamonds by simply hitting a tip above center with a medium stroke, or a medium soft stroke on fast cloth. It surely isn't a power shot, but it should be considered a forced-follow shot if any top spin imparted on the CB kicks in after it contacts the OB. The top spin forces the CB forward at a faster rate than its natural roll. In other words, if the the CB is "forced" forward after impacting the OB, it could be called a "force" follow shot.

When normal speed, combined with a natural roll, will not get the CB where it needs to go, you must force it. It may not always be a power stroke, but it's still a forced shot. This applies to top/forward spin as well as draw/back spin. I mean, a draw shot is simply a force-follow shot in reverse. It's a torque applied to the CB that takes effect immediately after striking it. It either dissipates (due to table/cloth friction) prior to the CB contacting something, like an object ball or a cushion, or it forces the CB forward or reverse after it makes contact with an OB or a cushion.

Here's an example of a power-stroked force follow in slow motion.... Power Stroke -- Force Follow

I also recorded two other follow shots, one with a medium firm stroke and one at with a medium soft stroke, but didn't upload them to YouTube. The medium firm shot clearly showed the top spin kicking in and forcing the CB forward after contacting the OB. It didn't climb up the back of the OB as dramatically as this power follow shot did, but the forced torque was easily noticed. The medium soft stroke gave a natural CB roll through the OB.
 

Bobkitty

I said: "Here kitty, kitty". Got this frown.
Gold Member
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Ok...this all makes sense. So is there an official definition of FORCE FOLLOW?

With the correct speed, one could send the CB following the OB a distance of six diamonds by simply hitting a tip above center with a medium stroke, or a medium soft stroke on fast cloth. It surely isn't a power shot, but it should be considered a forced-follow shot if any top spin imparted on the CB kicks in after it contacts the OB. The top spin forces the CB forward at a faster rate than its natural roll. In other words, if the the CB is "forced" forward after impacting the OB, it could be called a "force" follow shot.

When normal speed, combined with a natural roll, will not get the CB where it needs to go, you must force it. It may not always be a power stroke, but it's still a forced shot. This applies to top/forward spin as well as draw/back spin. I mean, a draw shot is simply a force-follow shot in reverse. It's a torque applied to the CB that takes effect immediately after striking it. It either dissipates (due to table/cloth friction) prior to the CB contacting something, like an object ball or a cushion, or it forces the CB forward or reverse after it makes contact with an OB or a cushion.

Here's an example of a power-stroked force follow in slow motion.... Power Stroke -- Force Follow

I also recorded two other follow shots, one with a medium firm stroke and one at with a medium soft stroke, but didn't upload them to YouTube. The medium firm shot clearly showed the top spin kicking in and forcing the CB forward after contacting the OB. It didn't climb up the back of the OB as dramatically as this power follow shot did, but the forced torque was easily noticed. The medium soft stroke gave a natural CB roll through the OB.

Nice video! And if someone does this shot near head on the OB and into a rail, it just kills itself as we all know with ball-in-jaws. Have a table that runs off badly and you want to hang the ball up by the rail, this is the way to do it. But, I've seen many, many other ways to use FF on shape and busting out balls. Many times it's the only way to get the CB where it needs to go. Question; how many of us work on this? Most of us have probably never seen it used in a very useful way like my teacher can do time after time. Watching him has convinced me to work on it. I will try to film and video a few unique shots.
 
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BC21

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Nice video! And if someone does this shot near head on the OB and into a rail, it just kills itself as we all know with ball-in-jaws. Have a table that runs off badly and you want to hang the ball up by the rail, this is the way to do it. But, I've seen many, many other ways to use FF on shape and busting out balls. Many times it's the only way to get the CB where it needs to go. Question; how many of us work on this?

To be honest....I don't work on it. When a shot comes up that requires a power force follow, I just give it the power and hit the CB a tip above center. It's not the most controlled shot, but I suppose if you work on it you can get an excellent feel for exactly how much power is needed based on distance between the CB and OB. For me it typically doesn't get used all that much so I don't invest much time into perfecting the shot. When I need it, it automatically works.
 

Bobkitty

I said: "Here kitty, kitty". Got this frown.
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To be honest....I don't work on it. When a shot comes up that requires a power force follow, I just give it the power and hit the CB a tip above center. It's not the most controlled shot, but I suppose if you work on it you can get an excellent feel for exactly how much power is needed based on distance between the CB and OB. For me it typically doesn't get used all that much so I don't invest much time into perfecting the shot. When I need it, it automatically works.

When the CB bends, as it does with draw, with FF, the bending of the CB can be very useful. Around balls that would be in the normal path, as I have shown in the video I posted the other day, but there are many other useful things. I guess if one hasn't seen it, it doesn't get into our knowledge.
 

skipbales

AzB Silver Member
Silver Member
Ok...this all makes sense. So is there an official definition of FORCE FOLLOW?

With the correct speed, one could send the CB following the OB a distance of six diamonds by simply hitting a tip above center with a medium stroke, or a medium soft stroke on fast cloth. It surely isn't a power shot, but it should be considered a forced-follow shot if any top spin imparted on the CB kicks in after it contacts the OB. The top spin forces the CB forward at a faster rate than its natural roll. In other words, if the the CB is "forced" forward after impacting the OB, it could be called a "force" follow shot.

When normal speed, combined with a natural roll, will not get the CB where it needs to go, you must force it. It may not always be a power stroke, but it's still a forced shot. This applies to top/forward spin as well as draw/back spin. I mean, a draw shot is simply a force-follow shot in reverse. It's a torque applied to the CB that takes effect immediately after striking it. It either dissipates (due to table/cloth friction) prior to the CB contacting something, like an object ball or a cushion, or it forces the CB forward or reverse after it makes contact with an OB or a cushion.

Here's an example of a power-stroked force follow in slow motion.... Power Stroke -- Force Follow

I also recorded two other follow shots, one with a medium firm stroke and one at with a medium soft stroke, but didn't upload them to YouTube. The medium firm shot clearly showed the top spin kicking in and forcing the CB forward after contacting the OB. It didn't climb up the back of the OB as dramatically as this power follow shot did, but the forced torque was easily noticed. The medium soft stroke gave a natural CB roll through the OB.

That is a great video. It shows the cue ball hitting with enough force to bounce up in the air, spin like crazy then get traction and shoot forward. I think that is the action we all see in actual play. The idea that it keeps overspinning down the table without getting full traction is what I don't think happens. It is the collision which causes the overspin. Once there is traction the spin just increases the speed until there is another collision.

The force follow is the idea of hitting it with enough force to cause the collision to lift the ball and allow it to free spin, kind of giving it that burning rubber effect to start. This would require pretty close proximity to the object ball which seems to also be a component of force follow. If the object all is 3/4 of a table away I don't think you can actually do a force follow, can you? I think it is just a hard hit by the time it gets there no matter how high or hard you hit the cue ball. The break shot might be an exception due to the mass of the balls being struck. Even at distance we have all seen the cue ball bounce up into the air spinning forward then drop and continue. I am less sure that a single ball can provide the resistance necessary, at distance, to provide the stopping power to develop the overspin.
 

Bobkitty

I said: "Here kitty, kitty". Got this frown.
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That is a great video. It shows the cue ball hitting with enough force to bounce up in the air, spin like crazy then get traction and shoot forward. I think that is the action we all see in actual play. The idea that it keeps overspinning down the table without getting full traction is what I don't think happens. It is the collision which causes the overspin. Once there is traction the spin just increases the speed until there is another collision.

The force follow is the idea of hitting it with enough force to cause the collision to lift the ball and allow it to free spin, kind of giving it that burning rubber effect to start. This would require pretty close proximity to the object ball which seems to also be a component of force follow. If the object all is 3/4 of a table away I don't think you can actually do a force follow, can you? I think it is just a hard hit by the time it gets there no matter how high or hard you hit the cue ball. The break shot might be an exception due to the mass of the balls being struck. Even at distance we have all seen the cue ball bounce up into the air spinning forward then drop and continue. I am less sure that a single ball can provide the resistance necessary, at distance, to provide the stopping power to develop the overspin.

No, on a 9' table hitting a ball-in-jaws and you hit over 3/4 ball with the CB on the end rail and the ball just stops near the pocket no matter how hard you hit it, that is FF. This is why you have to hit the ball with such a full hit with low english to get the CB back to where it started.
 

skipbales

AzB Silver Member
Silver Member
Nice video! And if someone does this shot near head on the OB and into a rail, it just kills itself as we all know with ball-in-jaws. Have a table that runs off badly and you want to hang the ball up by the rail, this is the way to do it. But, I've seen many, many other ways to use FF on shape and busting out balls. Many times it's the only way to get the CB where it needs to go. Question; how many of us work on this? Most of us have probably never seen it used in a very useful way like my teacher can do time after time. Watching him has convinced me to work on it. I will try to film and video a few unique shots.

Like a lot of occasional use shots it probably doesn't get enough practice. Just like hanger shots. Few practice them and even fewer can get position off of one when they need it. I practice not doing it by accident when I work on hanger shots. With a hanger if you are trying to come back down table and hit it too full you get that collision induced overspin with the second collision (with the rail) and the cue ball stays right there, the opposite result of what you intended.
 
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