This should be a simple one and probably gets repeated at least once a year.

Treat me like the novice I am, could someone explain the Bradshaw Scale for me?

Hope this is still accurate:

That seems to settle it.

Thanks.

Carlos-

That's a great idea!

FAQ page would answer many of the common questions.

And the good answers like Jeff's above coud be copied and pasted right to it without much trouble.

Now, ... what did you say about the County Detox in LasVegas?

-AncientOne

AncientOne wrote: Now, ... what did you say about the County Detox in LasVegas?

Hey, the coffee sucks but I swear they make the fluffiest pancakes in Nevada.

Wayne: You say the same thing everytime the issue comes up. Can we agree that this is probably the best system out there now?  I know that the RMSA would look at any modifications to the formula or an entirley new formula.

By the way, the RMSA most likely would use a caber that scores 790 as the main caber (after qualifier/before the "big stick") for the "A" class. or as a qualifier for the Pros.  The thing that might be throwing off your comparisons is if your throwing a lot of hard wood cabers vs. lodge pole or ponderosa pine.  The typical athlete can turn a longer and heavy hard wood stick due to the taper.

Tim wrote: I've thrown many a caber in my time and I've found that I ALWAYS have trouble with the longer cabers.  I can turn a 15' 150 lb caber but I have the damndest time with a 20' 90 lb stick.  It has always seemed to me that there are more forces that need to be taken into consideration to score a caber.

Any current or potential formulas will have flaws based on the bias of the creator. In addition, in order to consider the variables, the complexity would become challenging for non-math people. In the Bradshaw, the taper is the key factor with height and weight being "equal" in their consideration. However, with a balanced caber (centerpoint is center of gravity) a 30ft 100lb caber is of equal value as a 10ft 300lb caber. While I am not a seasoned caber turner, I would argue the challenge level of a caber is not linear.

Tim does address a good point. At what height, weight, or other consideration does a caber become more challenging to turn? Consider height alone, is a 24ft caber more challenging than an 22ft, a 22ft more challenging than an 20ft, a 20ft more challenging than an 18ft?

The answer is longer is much more difficult.

I consistently have more of a challenge with cabers over 17' than I do with sticks under 17'.

I still choke in competition either way, but longer is harder.

I agree Ed, and you have illustrated my question well with your 17' answer. Does the challenge become exponential beyond x ft? Unlikely, but it does need to be considered with greater emphasis than a shorter caber.

How about doubling up the length past 15 feet.

L1 = length up to 15'  (is =15 if the caber is greater than 15 feet)
L2 = length past 15' 

L2 = 0           ;           ;       If total Caber length is less than 15 ft
L2 = Total Length -15      If total Caber length is greater than 15 ft 

W=weight
T=Taper factor

Old Formula = (L1 + L2)  X W X T X 0.55
New Formula = (L1 + 2 X L2) X W X T X 0.55

That would move Waynes Caber from 788 to 960

Only thing needed is a bunch of data points that have

Length, Weight, Taper, # who tried to turn it, # who turned it, class

I think then a person could use the data to modify the breakpoint (15 feet) and the multiple (2) to get perhaps a better formula. 

This formula is not based on some physics calculation -- It is a simple way of taking into account that longer cabers are harder to  turn.   Given that I pulled 2 and 15 out of my arse, I would assume that as parameters to an equation, they stink!  Math humor?

I agree that peice wise does not have elegant mathematical properties --

I do like the proportion to moment of inertia

I am assuming then M = Mass or weight

To take into account the taper of the caber, I am assuming that
L then is the distance from the large end to the center of mass?

or using the notation from Bradsaw formula:

A = The distance from the large end to the center of gravity

Moment Formula = 0.1389 * Weight * A^2

0.1389 was the value to Make your 19'2" , 88# caber score a 950 so that it is comparable to the two peice formula

Is a 17' stick weighing 100# with no taper equally or slightly harder to turn then your 19'2" stick used at MWC?

I also believe that if a formula is to be calibrated, The score of 1000 should have some meaning in that it is damn hard to impossible for mear mortals to turn OR perhaps use some of the measurments from the historic Braemar Cabers that are in Highland games legend:

An  X pound caber with Y taper that is Z feet long would generate 1000.

I have not turned enough cabers to say what a 1000 caber should be.

No matter what is used as 1000 score, I think Mr. Wayne Hill's idea is a much better caber formula than the others.

I don't have the mathematical background to tackle the solution for this problem, but I do enjoy a mental challenge.  Some of what I'm saying is a restatement of what Wayne and the other have already said, so I apologize if it seems I'm presenting other people's ideas as my own.

Don't forget to consider that center of gravity refers to the balance of the object and is only evaluatable in the horizontal plane.  Wayne touched on this.  If you're using a straight, uniform caber, then the center of gravity is going to be the center of the distance of the widest end.  If the caber tips a few inches in any direction, the overall distance on the horizontal plane increases, and the effect is the aforementioned shifting of the center of gravity.  Would assessing the rate at which either the distance increases or the center of gravity shifts under "free-fall" conditions offer something predictive to the difficulty of the caber?

Wayne Hill wrote: McSanta wrote: No matter what is used as 1000 score, I think Mr. Wayne Hill's idea is a much better caber formula than the others. Oh, no you don't, wise guy!  It's not a formula yet:  we've just described the problem. -Wayne

Well okay I tried and If I was making the post now, I would have said I am starting to see the framework of a better formula because I am now seeing the complexity of the problem -- For once in my life I wish I took Physics with all my math because I am on a very steep learning curve. 

However, if one can mathematically quantify the forces at play, would it not be wise to use an approximate and hopefully simpler formula in the application?

McSanta wrote: However, if one can mathematically quantify the forces at play, would it not be wise to use an approximate and hopefully simpler formula in the application?

Yes.  Yes it would.  But you have to smart it up before you dumb it down.

McSanta wrote: For once in my life I wish I took Physics with all my math because I am on a very steep learning curve. However, if one can mathematically quantify the forces at play, would it not be wise to use an approximate and hopefully simpler formula in the application?

Forces can be identified, however, to be quantified additional variables enter for consideration. If forces are to be considered within a formula, they would need to be done in a neutral environment (lack of wind, etc).

We can make the games so complex that they begin to lose their appeal, somewhat anyway.

I like what I named, years ago, the California System.  Why that name, because that's the first place I ever ran into it.....

1 Caber per class, three throws,  ALL THROWS COUNT.  Finish the caber and move on. 

If the throwers want more or the crowd does, have a Challenge Caber.

When we did decathlon scoring, we needed computers, and a good program to not only calculate the caber points, but keep track of the standings and overall points.

If the cabers had not been scored prior to the games, someone had to determine center of gravity, distance to top, bottom, equations, weights, etc., and then document all this.  And, if you are totally legit, cabers change from year to year and perhaps, even game to game, so a repeat of the process may be needed.

I, for one, want the game to be done in the best, most simple format possible.  I prefer to spend my game day hanging with the guys and gals, throw, hopefully far, but just have a great day being Scottish for a day.

When I started they told me there'd be no math

We all use math everyday!  

Simple is always better when it comes to scoring. One never knows who they will have available as volunteers.

I have no particular attachment to the caber rating for the score within a specific game, but having a caber rating available allows for comparison to other athletes across the country, even though they may never see each other.

Note, I am not comparing myself, that's easy, I lose.  But it helps me to understand what sort of competition is out there.

And, I like the math.

I think the athlete should not be included in the formula.

The relative difficulty of turning a caber should be a stand alone concept.  The way in which an athlete compensates for their own particular build/experience/etc... is another thing altogether.  A slight guy may approach faster than a bohemoth, but if the caber is turned, either way the required force was the same.  It was just applied differently.

Wayne - Wouldn't the minimum runup speed be zero as in turning it braemar style? Minimum work/power could be achieved without forward movement of the athlete. I agree determination of the work/power required would yield a good rating scale.

Edward wrote: I think the athlete should not be included in the formula. The relative difficulty of turning a caber should be a stand alone concept.  The way in which an athlete compensates for their own particular build/experience/etc... is another thing altogether.  A slight guy may approach faster than a bohemoth, but if the caber is turned, either way the required force was the same.  It was just applied differently.

I concur.  The point is to have a rating for the caber, not the caber/athlete combo.

Wayne,

"This raises another question:  should the horizontal work be included in the analysis, or should the analysis only consider the work of the pull?  Although it seems reasonable to include both inputs, I know for my own part that it's a heck of a lot easier to get up a head of steam with a heavy caber than it is to flip it."

Question:  How would you measure the pull?  Considering that it is technically possible to pull straight up (upright row-style) resulting in the caber moving straight up and straight down no turn.  The pull is effectively an arc starting straight up and curving back toward the body resulting in hands behing the head, with the caber losing touch at some point along the curve.

I am not the mathematician, so how would you calculate the lift v flip power input?

For a scale to be comparable, I almost think you have to find a way that minimize the total work of accelerating and the pull and then rate the caber just on the work of the pull.

A simplifying assumption would assume the caber is moving at a certain speed and calculate the work of the pull based on that speed with the work of the pull would then be your scale.  This brings the scale back down to the given characteristics of the caber.

If I used terms wrong it shows my lack of physics background -- I am a trained Statistician not an engineer

Wayne,

As I consider this problem, I actually had to draw two arcs.  There is the first arc created by the falling force of the skyward (bottom) of the caber.  And the rising (top) of the caber.

The falling arc is representative of force created by the bottom when it tips past center and falls to the ground.  This would of course follow a normal gravity formula and only be modified by the height off the ground of the top held in the tosser's hands.

The rising arc is created by the force applied in the pull.

If I am not mistaken, the rotational force would be the result of the combined effect of the force in the falling arc beyond the center of gravity and the pulling force in the rising arc applied this side of the center of gravity.

The trick being to create sufficient force into to rising arc to allow the falling arc to pull the caber over.  (With a slight advantage to a taller athlete, which allows a longer falling arc)

Or, I could just be talking out of my arse.  

Thom,

I do a better job of visualizing the throw if I understand conceptually what has to happen to be successful.

So, I'm not just a caber geek, I do this kind of excercise with all the events.  I'm not a coach, but I bet some of the coaches on line do too.

Edward wrote: As I consider this problem, I actually had to draw two arcs.  There is the first arc created by the falling force of the skyward (bottom) of the caber.  And the rising (top) of the caber. The falling arc is representative of force created by the bottom when it tips past center and falls to the ground.  This would of course follow a normal gravity formula and only be modified by the height off the ground of the top held in the tosser's hands. The rising arc is created by the force applied in the pull. If I am not mistaken, the rotational force would be the result of the combined effect of the force in the falling arc beyond the center of gravity and the pulling force in the rising arc applied this side of the center of gravity.

but you're hitting on one mechanism that causes rotation:  if the CG of the caber is in front of your hands (caber leaning away from you), then there's a component of your pull that accelerates the rotation of the caber.

My analysis so far has ignored this effect, because you can obtain rotation from the forward speed of the caber's CG when you start your pull.  However, that has the effect of linking the rotational speed to the forward speed, which isn't such a great idea:  forward speed represents kinetic energy that can help kick the caber over if it's close to turning, while the rotational speed mostly determines the geometry of where the caber butt hits the ground (which is still a very important issue).

I suspect that, to do this right, you need to consider a range of:

• Runup speeds
• Caber tilt angles
• Pull energies

Run?  I don't get that.  The caber is there, the judge is there, the crowd is there, and the guy runs off with the stick.  Should be a foul.

My terminology is, umm, eccentric because I am not an engineer to state the obvious.  I'm a finance guy.

Here's the picture I sketched, then put in visio.

So you can see the two arcs I describe.  My thought process being that your really not throwing 80 to 100 lbs. over the full course of the arc.  Your really just moving the minimal amount of weight a given distance to allow the naturally occuring forces to take over.

I think this is true in any of the scenarios.  Run up, no run up, etc...

Sam:

You should come to Wyoming, just drive West; young man!

• Rate your cabers using the Bradshaw scale, but keep track of the particulars (length, weight, balance point).
• Compare cabers of similar ratings that have different lengths and weights.  Figure out which one is easier for people to turn.

I think you can rate the cabers but not the tosser.  Each person might have different abilities with different types of sticks depending on speed and power of each person.  And each tosser has many variables with injury, time of season, lunch quality and so forth.

There is also no place on the chart for amonia and emotional unload.  The caber is right after the hammer.  Some people might be very emotionaly upset after the hammer and have a tremendous unload on the dead wood.  Some people are just waking from their nap at lunch. 

There seems to be agreement that the Bradshaw formula captures the elements that should be used to rate/rank a caber.  

We also seem to agree that the formula does not give enough weight to those with longer cabers or to much weight with those with shorter cabers, so I suggested in the earlier post a simple way to adjust the Bradshaw formula.  As it was pointed out, the parameter or factor I used is probably not correct (since I pulled it out of the air).   As a trained statistician, I would love to have data to fit a model to. The problem is what data should I be using?

Wayne Hill wrote: People who really want to help should do the following: Rate your cabers using the Bradshaw scale, but keep track of the particulars (length, weight, balance point). Compare cabers of similar ratings that have different lengths and weights.  Figure out which one is easier for people to turn.

I will take Waynes idea one step further:

• Keep track of the parameters of each of your cabers (weight, length, distance to center of gravity),
• Note what people think is harder and easier to turn
• the class the caber is used in
• keep track of the number of attempts made to turn the caber and the number of successes though out the year. (should success be a turn or a 12:00 turn?) 

Either do this retroactively from last year's score sheets or make an effort to do it in the up coming season. 

At the end of the season, use this information to rank the cabers from easiest to hardest to turn in each class by a measure  = successes divided by attempts. 

From this point, we modify the Bradshaw formula in a manner that produces a score that with luck will closely reflect the rankings.