Break tip and cue weight questions answered by Dr. Dave

[mattiefingaz]

Good day all,
I've been recently trying to calculate mathematically which are better, phenolic tip vs. leather and light cue vs. heavy cue. After failing to come up with the right equations on my own I reached out to Dr. Dave, Colorado State University's resident pool math expert.

To sum up all of this info in a couple sentences, phenolic tips are more efficient and therefore provide increased speed.
If you can break at the same speed with a heavier cue than a lighter cue, use the heavier cue. The math is included in the second link.
Technique - Watch the video, very helpful.

Mattie

This may be old hat for some people but I wanted to share for those that it is not.

Thanks Doc for the FAST response and all the amazing information.



Concerning tips, phenolic tips have a higher "coefficient of restitution" resulting in better "efficiency." For more info, see:
http://billiards.colostate.edu/threads/cue_tip.html#efficiency

Concerning optimal cue weight, see:
http://billiards.colostate.edu/threads/cue.html#weight

Even more important than tip hardness and cue weight is technique. For more info, see:
http://billiards.colostate.edu/threads/break.html#advice

 

[td873]

Good day all,
I've been recently trying to calculate mathematically which are better, phenolic tip vs. leather and light cue vs. heavy cue. After failing to come up with the right equations on my own I reached out to Dr. Dave, Colorado State University's resident pool math expert.

To sum up all of this info in a couple sentences, phenolic tips are more efficient and therefore provide increased speed.

I seem to recall that the efficiency was only minimal​

...
If you can break at the same speed with a heavier cue than a lighter cue, use the heavier cue. The math is included in the second link.

I think this depends on what result you are looking for. [edited] Because e=1/2mv^2, a heavy stick traveling at the same speed as a light stick will impart slightly more force (ratio of mass), but do you really need more energy going to the cue ball. Put differently, are you losing control for more speed?​

A couple comments up there in red.

 

[mattiefingaz]

E=MC^2 is short for Energy = Mass accelerated to the speed of light squared. If you can break at the speed of light squared I'm legitimately scared of you. Perhaps you're thinking F=M*A, which is force equals mass times acceleration.

 

[mattiefingaz]

I forgot to add...there's a few things you don't do.

You don't pull on Superman's cape.
You don't spit into the wind.
You don't pull the mask off that old lone ranger.
And when it comes to physics and math as it relates to pool you don't mess around with David G. Alciatore, PhD.

 

[Bob Jewett]

... If you can break at the same speed with a heavier cue than a lighter cue, use the heavier cue. ...

It's also interesting to note that for most cues the cue ball will end up going faster than the cue stick is moving just before impact. If the tip is ideal, the number is about 150% of cue stick speed. For real tips it is more like 130--140%.

 

[Bob Jewett]

E=MC^2 is short for Energy = Mass accelerated to the speed of light squared. If you can break at the speed of light squared I'm legitimately scared of you. Perhaps you're thinking F=M*A, which is force equals mass times acceleration.

I suspect he was going for the kinetic energy in a moving mass which is given by:

energy = 0.5 * mass * speed * speed (E=1/2 * m * v^2)

The actual forces involved are not interesting unless you get very far down in the details.

 

[Busboy]

Dr. Dave is the man he knows his stuff

 

[Jaden]

you mean mass times the speed of light squared...

E=MC^2 is short for Energy = Mass accelerated to the speed of light squared. If you can break at the speed of light squared I'm legitimately scared of you. Perhaps you're thinking F=M*A, which is force equals mass times acceleration.

I think you mean mass times the speed of light squared, not accelerated to the speed of light. Mass cannot be accelerated to the speed of light because it increases in mass as it approaches the speed of light, eventually obtaining infinite mass.

This concept is often used to discount faster than light travel but that is a misnomer because it doesn't say anything about manipulating space/time itself as is currently being contemplated or using particles that are already traveling at or past the speed of light.

Jaden

 

[Cardigan Kid]

I forgot to add...there's a few things you don't do.

You don't pull on Superman's cape.
You don't spit into the wind.
You don't pull the mask off that old lone ranger.
And when it comes to physics and math as it relates to pool you don't mess around with David G. Alciatore, PhD.

That's funny stuff right there. Only us billiard geeks could get it, but funny nevertheless. :thumbup:

 

[Jaden]

The physics actually mean very little...

It doesn't matter if you can hit just as fast with a heavier cue (also, don't confuse break speed here with cue speed).

You first would have to be able to swing the heavier cue just as fast as the lighter cue not have the same break speed. The same break speed, all else being equal will equate to the same results, because the mass of the cueball doesn't change.

If you can swing a heavier cue just as fast as a lighter cue, it will result in more force and a FASTER break speed.

The problem with this is that a more square break, hitting the cb on the first contacted ball more accurately, will result in better and more consistent break results than a faster break speed will. You still want to be able to break as fast as possible, but accurately as well.

So the real question you should ask is what cue/tip/stroke combination results in the fastest, ACCURATE break for you as an individual.

Not to plug my own stuff, ok, to plug my own stuff a little bit, this is why my break tips are one of the best available, because it gives really high energy transfer while still providing grip on the ball, so spin or a slight off center hit won't as easily result in lower levels of energy transfer.

Jaden

 

[zpele]

Personally I like Samsara tips since they allow for greater control than phenolic while only sacrificing a little bit of speed.

For most players what it comes down to is 'don't worry about it and use a stick that you feel you can get the best break from.'

The break only really becomes important if you can pocket all types of shots correctly and play correct patterns.

There is a story about Buddy Hall:

A student asked Buddy Hall to help him with his break. In response Hall setup one of his pocketing drills and asked the student to run the table. The student ran a few balls and missed to which Hall said something like, 'why would I help you break better when you can't run a rack? I would only be helping out your opponent.'

Don't get too caught up in the math of this game. It is a fun pasttime but in general will not give the average player a leg up on their competition. There is no substitute for time at the table and the same can be said for breaking technique. Very few amatuer players have correct breaking technique and they would benefit far more from practicing technique over purchasing a magic wand break cue.

That being said I use a bk3 lol.

 

[I Got Lucky]

So when choosing a break cue, what is a good weight to go with?

 

[buckshotshoey]

So when choosing a break cue, what is a good weight to go with?

Download the break speed app. Try a few different cue weights. Whichever cue you can hit fastest with (AND WITH CONTROL) is the one to choose. There is really no way for any of us to tell whats right for you. Generally a lighter cue will get you better speed with less effort. Maybe start with one that is close to the weight of your playing cue.

 

[td873]

E=MC^2 is short for Energy = Mass accelerated to the speed of light squared. If you can break at the speed of light squared I'm legitimately scared of you. Perhaps you're thinking F=M*A, which is force equals mass times acceleration.

I wasn't thinking of f=m*a

I suspect he was going for the kinetic energy in a moving mass which is given by:

energy = 0.5 * mass * speed * speed (E=1/2 * m * v^2)

The actual forces involved are not interesting unless you get very far down in the details.

I was misremembering this and conflating with random junk in my brain.

In any event, the point being, the relevant portion is a direct ratio of the masses of the two sticks because velocity would be the same as proposed by the OP. So using a heavier stick by a few ounces isn't going to net a bunch of energy imparted to the cue ball. I think.

-td

 

[owll]

It's also interesting to note that for most cues the cue ball will end up going faster than the cue stick is moving just before impact. If the tip is ideal, the number is about 150% of cue stick speed. For real tips it is more like 130--140%.

how can cue ball be going faster than cue stick just before impact...when the cue ball is just sittin there? (snicker)

 

[mantis99]

I think you mean mass times the speed of light squared, not accelerated to the speed of light. Mass cannot be accelerated to the speed of light because it increases in mass as it approaches the speed of light, eventually obtaining infinite mass.

This concept is often used to discount faster than light travel but that is a misnomer because it doesn't say anything about manipulating space/time itself as is currently being contemplated or using particles that are already traveling at or past the speed of light.

Jaden

Agreed. Especially since nothing with any actual mass can travel the speed of light.

 

[mantis99]

I suspect he was going for the kinetic energy in a moving mass which is given by:

energy = 0.5 * mass * speed * speed (E=1/2 * m * v^2)

The actual forces involved are not interesting unless you get very far down in the details.

This is a very important concept to understand for this discussion. Because velocity is squared in this equation, the speed actually matters more than the mass. Thus, a lighter cue that you can move faster may allow for a faster overall break. The same holds true for baseball bats, and is why Babe Ruth's ginormous bat probably actually held him back more than it helped him. There is of course a law of diminishing returns also. If te mass becomes too light compared to the object it is coming in contact with, then it won't propel the object forward very well, especially without sustaining damage to itself. None the less, it is often a misnomer that using a heavy 21 ounce cue is better to break with than an 18 ounce cue, because many people lose too michc velocity with the heavier cue.

 

[owll]

I wonder how momentum would play into this (mass x speed).

To me, it seems fine to use kinetic energy in regards to cue ball hitting rack of balls. But is momentum more appropriate for stick to cue ball?

I dont know, just expressing a thought in the hopes that someone who knows more chimes in

 

[Grantstew]

This is a great discussion... Takes me back to my highschool maths

Kinetic energy =
MV squared
------------------
2

I would have thought that the best weight of cue to use is the same as your playing cue.

Whether a cue is 18oz or 21oz, there is not going to be a whole lot of difference in the energy transferred to the cue ball when breaking at the same speed with each. Lighter should probably equal more control.

The only scenario where I see a heavier cue having an advantage is if you are breaking with a contact point anywhere along the vertical axis of the cueball.

 

[Bob Jewett]

how can cue ball be going faster than cue stick just before impact...when the cue ball is just sittin there? (snicker)

I'm not clear on whether you're really confused or just playing with the wording. This wording may be less ambiguous: If the cue stick is moving at 10 ft/second an instant before the tip hits the ball, the ball will be moving at about 13ft/second just after it leaves the tip.