power vs. speed on the break

[dave sutton]

what do the science guys say

has anyone done this?

do you generate more MPH at impact by throwing a lighter cue faster or a heavier cue slower?

its the classic question.

is 18oz better then 22oz

all being equal. not looking for position or scratching ...JUST MPH

 

[jasonlaus]

Good question. I have my own opinion, but would like to hear science guy's thoughts also.

 

[Chembry]

Power vs. Speed

I am a PhD student in chemistry, but had to take quite a bit of physics while during my undergraduate career. This is (for me) a complicated discussion. There are different types of collisions in physics elastic, inelastic, etc... I used a formula that may not be exactly correct but will give you an idea. I used the conservation of momentum meaning that all energy created during the swing of the break is conserved (most of the momentum going to the cue ball while some stays in the break cue as it moves toward the rack after impact, and the rest is absorbed by your body moving forward as you break). With all things being equal more MPH will be generated with the heavier cue. There are other things to consider but I think this gives you a good idea.

 

[TXsouthpaw]

what do the science guys say

has anyone done this?

do you generate more MPH at impact by throwing a lighter cue faster or a heavier cue slower?

its the classic question.

is 18oz better then 22oz

all being equal. not looking for position or scratching ...JUST MPH

good question. come on science guys. settle this thing once and for all.

 

[Jal]

what do the science guys say

has anyone done this?

do you generate more MPH at impact by throwing a lighter cue faster or a heavier cue slower?

its the classic question.

is 18oz better then 22oz

all being equal. not looking for position or scratching ...JUST MPH

There is a theoretically optimum weight which depends on the rotational inertia of a player's arm. It's different for each player. But this is very hard to determine independently. I don't know of any way, short of amputation, or simply trying out different cues.

But calculations based on a fixed amount of maximum applied force also indicate that the cue's mass is not critical. You can be many ounces off the optimum and still get virtually the same result. Broadly speaking, hedging toward too heavy is probably better than hedging toward too light, since it might allow you to generate more maximum force (try applying 10 pounds of force to a particle of dust).

Jim

 

[dave sutton]

let me edit my post...

i dont mean all things equal. balls table ect not cue or speed

obv the heavier cue wins

the question is can you generate more MPH by throwing a lighter cue faster


in other words does more speed less weight trump more weight less speed MPH wise at the rack

 

[Island Drive]

let me edit my post...

i dont mean all things equal. balls table ect not cue or speed

obv the heavier cue wins

the question is can you generate more MPH by throwing a lighter cue faster


in other words does more speed less weight trump more weight less speed MPH wise at the rack

Ask the martial arts people...

 

[Jal]

...the question is can you generate more MPH by throwing a lighter cue faster


in other words does more speed less weight trump more weight less speed MPH wise at the rack

It's a question of how much cue speed a player can produce given the weight of the cue. A cue can be too heavy or too light for a particular player. At the extremes, no one is going to get much cueball speed from a 100-pound cue, or a 1-ounce cue. If arms had exactly zero rotational inertia (zero mass), the optimal cue weight would be the weight of the cueball, or 6 ounces. But since they don't have zero mass, optimal cue weight is larger.

This could be figured if you knew what the rotational inertia was for a particular player. But how do you determine this? Generally speaking, the more massive a player's arm, the heavier will be the cue that provides the most cueball speed. But as you increase the weight, at some point it will become too heavy and cueball speed will start to tail off.

As mentioned, it doesn't seem to be critical. You probably won't notice much difference if you're 2, 3, 4 or maybe even a few more ounces off the optimum. This is based purely on physics, not on how much force the muscles are capable of generating against different opposing masses.

Jim

 

[Shaft]

I am one of many engineers on this forum. We've had this question many times....

If you consider the energy input into the cue is the maximum force your muscles man muster over your stroke distance - and keep that variable the same - here is my opinion which I believe is supported by science, but I warn you it will seem counter-intuitive:

Kinetic Energy of the cue/arm assembly = arm force x stroke distance.
The kinetic energy of the light cue/arm assembly will be the SAME as the heavy cue/arm assembly, but the light cue will have more speed because it has less mass and can be accelerated more by the same force. (Turns out, the difference in speed does not matter.)

The closer two colliding objects are in mass, the more efficient is the transfer of kinetic energy between them. The lighter cue will transfer a higher percentage of its kinetic energy to the cue ball, while the heavier cue will retain more of its kinetic energy. Engineers call this the "coefficient of restitution." When two objects have the same mass, the transfer can be 100%, as seen with a straight-in stop shot collision between two balls.

I believe this is exactly what a robot would show: The lighter cue generates more cue ball speed (kinetic energy) because of the more efficient transfer of kinetic energy. I did the calculations once and the difference between 18oz and 21oz was not that much (Upper bound of 15%, not counting arm mass? I don't remember, I'll look it up).

The problem is that humans are not robots and there may be a physiological ability to push more against a heavy mass, achieving a similar speed (higher kinetic energy) with the more massive cue. I don't think anyone on this forum has a scientific answer to THAT question.

In discussing this, most people make one of the following two errors:
1. they assume the cues will have the same speed (incorrect) and therefore the heavy cue will have more energy (which would be correct if they had the same speed, but they don't), or
2. that the cues will have different speeds and that speed, not energy, is what makes the difference. (Energy is what counts, but since the energy is the same in both cases, it is the coefficient of restitution that makes the difference).

 

[southpaw72]

I'm not sure if the same thing applies to pool, but in archery a heavier slower arrow will produce better penetration than a lighter faster arrow.

 

[Snorks]

Just a question, what once bat does a home-run hitter use in baseball? I haven't played in 20+ years but I distinctly remember I could hit the ball a hell of a lot further with a slightly heavier bat.

Home run hitters used the heavier bats.
Smaller guys used the lighter bats.

Not sure if this applies here or not. For the record, I use about the same weight in both my break and playing cue, works fine for me.

 

[daphish1]

Just a question, what once bat does a home-run hitter use in baseball? I haven't played in 20+ years but I distinctly remember I could hit the ball a hell of a lot further with a slightly heavier bat.

Home run hitters used the heavier bats.
Smaller guys used the lighter bats.

Not sure if this applies here or not. For the record, I use about the same weight in both my break and playing cue, works fine for me.

I think a bat hitting a baseball is a different comparison, you are taking two moving objects and the heavier bat will have a greater impact then something hitting a stationary object. I think it comes down to mechanics and how someone puts together a good stroke on the ball. There was a video on here of Hillbilly talking about the break and the timing that is involved. I think this is more comparable to a 5'9" skinny guy drilling a golf ball over 300 yds, that is a result of having good mechanics.

 

[worriedbeef]

bottom line (imo):

lighter cue technically can be moved faster which generates more speed resulting in a harder break. and a heavier cue is harder to accelerate as fast but generates more momentum.

but the thing is we are all human and are all unique.

therefore it depends on your body type and your physical build as to what is better for you.

generally, bigger/bulkier, slower people are suited to a heavier cue. And smaller, faster, lighter people with are suited to a lighter cue.

break technique is also very important too. you know sometimes when you get the timing just right and the whole of your body seems to have moved perfectly in time and the break just felt awesome? achieving that would be the biggest factor in a great break. but of course the right weight cue is very important too.

 

[Fatboy]

what do the science guys say

has anyone done this?

do you generate more MPH at impact by throwing a lighter cue faster or a heavier cue slower?

its the classic question.

is 18oz better then 22oz

all being equal. not looking for position or scratching ...JUST MPH

i had alot of physics in college and studied ballistics for reloading ammo for years, having said that I would like to know too.

what i have experienced defys physics and dosent make sence, I can move a lighter cue faster but the balls dont open up as good, and I get harder breaks with a slower heavier cue-both of which are impossible!!!

I would really like to know myself

 

[td873]

do you generate more MPH at impact by throwing a lighter cue faster or a heavier cue slower?

all being equal. not looking for position or scratching ...JUST MPH

Without going into great detail, a "lighter cue faster" is the probably the correct answer. This is because force increases exponentially as velocitiy increases; and only linearly as mass increases. F=MV^2. Generically speaking, if you can move a lighter stick faster through your stroke than a heavy stick, you'll hit the cue ball with more force, and it should go faster down the table. Of course, there is a point where a heavy stick will be the right answer, but someone else will chime in and explain how all this works.

Here is a thread on point:
http://forums.azbilliards.com/showthread.php?t=78353

-td

 

[poolpro]

Lighter cue is going to get you more cueball speed!! I am certain.


Obviously if an 18 oz cue and a 22 oz cue were bothe swung at the same speed than the 22 oz cue would give you more cueball speed. In reality it isn't the case.

You can swing a lighter cue faster.

You will not make up in extra mass for what you lose in cuestick speed by switching to a heavier cue.

It is a combination of mass AND momentum. In this specific case, the momentum will have a greater impact on the outcome.

To use an exxageraration: If you are hitting a baseball, which would give you greater distance? A bat or a log? You will be able to swing a bat much faster.

Also a major influence is what your muscles are used to. If you routinely play with a 19 oz cue, your muscles are used to it and are comfortable with it. Now you are going to grab a 22oz cue AND try to swing it as hard as you can. It doesn't work so good. It will be a shock to your muscles and will be more awkward to control well on such a critical shot.

Think of a runner who trains wearing ankle weights. His muscles get used to the extra weight, and when it is removed his performance goes up. Just like a batter who warms up using 3 bats, then puts down 2 before he steps up to bat.

I strongly recomend using the same weight or less than your playing cue. Play with a 19 and break with an 18.5 or 18. Play with a 21 and break with a 20 or 19.5.


Robert Byrne discusses this exact thing in the beginning of one of his books. I believe it was the Advanced book of pool and billiards. They actually did a test on a table with the rails removed and measured the distance the cue ball landed away from the table.

I will look forward to a much better explanation than the one I have just offered.

I have no doubt that a lighter cue will generate more cue ball speed for the same player. This is also assuming it stays within the sensitive practical range of 18-22 oz. Obviously if you go down to like a 14 oz cue things start to change.

And as has already been stated. If player A uses a 19 oz cue to break, and player B is able to swing a 21 oz cue at the same speed ( as player A), player B will generate more cue ball speed.

I am suggesting that the same player with a set of fixed mechanics/fundamentals/ strength and breaking technique will achieve more cueball speed with a ligher cue than his playing weight than a heavier one. With the only variable being the weight of the cue.





Jw

 

[Shaft]

Sorry for the long post....Here's the math....

If the force and distance is the same with both cues (like with a robot like Iron Willie or Meucci's Myth Destroyer), the light cue will win. See the math exercise below.

(But, if the human arm "maxes out" at a top speed regardless of force, then the heavy cue might win, depending on its extra energy relative to its less efficient coefficient of restitution. I don't know if the human arm maxes out on speed.)

Here is the math that I posted almost a year ago on the Billiards Digest CCB forum:

For the purpose of this analysis I will assume that

* The collision is perfectly elastic (energy and momentum will be conserved in the post collision motion of the stick and ball).

* The same shooter exerts a constant force (300 Newtons, about 67.4 lbs) over a 6 inch forward swing to impact. (The actual force and swing distance are not important here so long as they are the same for both cues.)

* The "light" stick weighs 18oz, the "heavy" stick weighs 21oz, and the cue ball weighs 6 oz.

* The stick and ball are free bodies in space. The the stick is accellerated to hit a ball that is initially at rest, and the axis and path of the stick is alligned with the center of the ball. (I know real balls and sticks are not free bodies in space, but this assumption simplifies everything without changing the outcome. I am deliberately ignoring arm mass, so the calculated numbers will be inaccurate, but the winner will be the same.)

The trick is to find the post collision speeds of the ball and stick so that energy and momentum are conserved. We have a system of two equations and two unknowns, so it can be solved with some hairy algebra. I used the Excel Solver routine because it was easier and I am LAZY.

A constant force of 300N applied over 6 inches will accelerate an 18oz (0.5103kg) stick to a speed of 13.38614 m/s (29.94mph). The pre-collision momentum of the stick is 6.830947 kg-m/s, and the kinetic energy is 45.72J. Conserving energy and momentum, the post collision speed of the stick is 6.69307m/s (14.97mph) and the post collision speed of the ball is 20.07m/s (44.92mph).

A constant force of 300N applied over 6 inches will accellerate a 21oz (0.5953kg) stick to a speed of 12.39368m/s (27.72mph). The pre-collision momentum of the stick is 7.377956 kg-m/s, (NOTE: MORE MOMENTUM THAN THE LIGHTER CUE) and the kinetic energy is 45.72 J. NOTE: THIS IS THE SAME KINETIC ENERGY AS THE LIGHT CUE. Conserving energy and momentum, the post collision speed of the stick is 6.885376m/s (15.40mph) and the post collision speed of the ball is 19.27905m/s (43.13mph).

DRUM ROLL and TRUMPET FANFARE:::::::::::::
Admittedly ignoring arm mass, the cue ball has - at most - 4.1% more speed and 8.5% more energy when struck by a LIGHTER (18oz) stick than when it is struck by a HEAVIER (21oz) stick, all other things being equal. A 15% reduction in weight results in no more than 4% more speed.

This is true - NOT because the lighter stick moves faster - but because the lighter stick transfers more energy to an object that is more similar in mass. Coefficient of restitution.

In fact, I demonstrated with the same spreadsheet that, as the mass of the two colliding objects gets more and more equal, more and more of the energy of the first object is transfered to the second object. When the mass difference is zero, the energy transfer is 100%.

We can see this principle on the pool table. A dead-stratight stun shot transfers nearly 100% of the cue ball energy to the object ball. (It is ironic that a clue to the answer has been in front of us all the time.)

In this case, physics CONFIRMS anecdotal observation.

I suppose we should all go out and buy 6oz cue sticks!!! (That's meant to be a joke...)​

 

[dave sutton]

thanks for the input guys

my opinion was lighter was faster.

then the guy with the 24oz cue come in and tells me i couldnt be more wrong.

funny

 

[Jude Rosenstock]

I once asked someone what the most important aspect of 9-ball was. He said, "It's the break. The break defines everything." This is not an unusual statement.

I then asked, "Who do you think is the best 9-ball player in the world?"

He answered, "Without a doubt, Efren Reyes."

I said, "What do you think is the weakest part of his game?"

He answered without hesitation, "His break. He doesn't break harder than 20 mph."

Go figure. Best player in the world has a weak break.

 

[shinigami]

I once asked someone what the most important aspect of 9-ball was. He said, "It's the break. The break defines everything." This is not an unusual statement.

I then asked, "Who do you think is the best 9-ball player in the world?"

He answered, "Without a doubt, Efren Reyes."

I said, "What do you think is the weakest part of his game?"

He answered without hesitation, "His break. He doesn't break harder than 20 mph."

Go figure. Best player in the world has a weak break.

I think that's his weakness by default...they can't critique any other part of his game. His break is by no means...weak.