Back pattern manipulation via polygenic traits and impact on morphs

The biggest misconception holding people back from selective breeding efficiently, is by far thinking morphs have variation.
The only way a morph can have variation within the gene itself, is if its polygenic genes and theres some secondary interaction happening somewhere to cause variation.
I cant think of a single morph that acts like theres a secondary gene attacked to it that sometimes expresses in a different way.
The issue comes from seeing so many different looks from a morph.  Naturally people start to think morphs have variation in phenotype expression.  Technically they do, but the cause of that variation isn't within the gene itself. 
Tigers, and marbles are the most notable for obvious variation.  Ocelot is another gene that no two really look alike.
The thing those three have in common is they are pattern structure altering morph. 
The reason no two look alike is because no wild type pattern looks alike.  No two patterns are the same. 
Kind of like finger prints.  All finger prints look similar but no two are the same. 
Just like, no retics have identical back patterns. 
So its impossible for tigers, marbles, and ocelots to be identical. 
They alter pattern structure but all individual patterns are unique. Every tiger, marble, and ocelot is unique. 
This is where the variation comes from.  It has nothing to do with the morph and everything to do with the traits that determine the specific pattern of each individual retic. 
This is the first roadblock to selective breeding.  Which is, not understanding what you're actually trying to manipulate.
Breeders make the mistake of trying to manipulate the look of a retic by adding a morph only.
It does manipulate the look of a retic, but only so far as the morph can change the specific part of the color and pattern it affects. 

Thats where the morphs ability to change the look of retic stops, and selective breeding begins. 
Selective breeding is the manipulation of both color and pattern but also of morphs as well. 

You cant manipulate the tiger gene without adding the polygenic traits to get the change you want.
There are potentially thousands of genes on a chromosome and hundreds to thousands of locus with gene clusters, that effect the pattern and color of retics. 

Which chromosomes have the genes that morphs change and whats the number of possible pattern and color outcomes for variation of the typical phenotype expressed, we have no idea. 

I can tell you there is predictability of morph expression when combined with certain wild type looks. 
In another article i talked about what i consider to be the seven aspects of back pattern structure that determines its look and also determines the look of the morph. 
Those seven aspects are 
thickness of black
diamond shape 
diamond count 
diamond width 
diamond length 
proximity of diamonds to each other 
proximity of diamonds to the rosette

These are the seven aspects of back pattern structure iv identified as being the determining factors that control the individual look of a morph. 
This is where the variation in morphs comes from.
Its not coming from the morphs themselves.  

The aztec morph has been at the front line of the selective breeding debate.  Mainly as a question of why dont US aztecs look like the aztecs overseas?
The answer is simple.  Lack of genetic diversity.  There is far more genetic diversity in retics overseas than in the US.   Outside of super dwarfs, theres not been many localities added in for genetics out crossing.
And super dwarfs are probably the most naturally inbred retics there are. 

Not only is there an issue of lack of genetic diversity in the US.  There is also a lack of polygenic trait diversity in the US. 
Keep in mind all albinos came from one snake.  Most retic morphs came from one snake.  So theres really only a handful of different polygenic traits in the morph combos getting produced.
Take an albino gc sunfire.  Thats three genes that have been bred to everything and to each other hundreds of times.
Theres no chance for different polygenic traits getting added.
Its the same genes getting bred back to each other. 
With no variation in traits theres no real variation in look.
Thats why regardless of who makes a mainland albino gc sunfire they look the same.  Plus the limiting effects those genes have on color and pattern they arent going to help.

This is the polygenic trait bottleneck existing in most breeders collections, causing the mediocre looks.
Theres a reason, if you lined up marbles, tigers, platinums, sunfires, ect from a lot of different breeders collections, you wouldn't be able to tell them apart.
Now if one of each from my production was added and you were asked to pick out which ones are from Rodney Boalich.  Theres about a 100% chance you could pick out which ones i produced.  
My production looks noticeably different from other people because my collection of retics has noticeably more genetic diversity.
That allows me to selectively breed in a way that makes color and pattern manipulation easy.  Im not fighting against ten generations of inbreeding.  Its a lot easier to change the way a morph looks when every chromosome isnt packed full of the same secondary traits. 
Understand that diversity seen in a morph isnt a function of the morph, but the result of the alignment of secondary traits.  Next, realize that the past breeding practices of retics has bottle necked the genes that create variation. Which limits selective breeding by taking away different possibilities of morph variation. 
Now taking into consideration what a morph actually does. 
Chances are it takes something away, not adds something.  Or it exaggerates the typical look in some way.  Even this usually comes at the cost of some color or pattern.
This is how you move forward with a plan for selective breeding.

The mistake of thinking morphs have inherent variation is usually followed up with thinking they are adding pieces to the genetic puzzle.  This has brought us more striped out, no contrast, patternless retics, then i can count. 
Once you move passed all those misconceptions, its time to start adding the secondary traits you need for morph manipulation. 
What you need to add depends on what you're trying to do.   If you're trying to change back pattern in some way you need to figure how you are trying to change it.  
Lest take a marble for example.  If you want a chaotic back pattern you have to pair up the right pattern traits.
thickness of black
diamond shape 
diamond count 
diamond width 
diamond length 
proximity of diamonds to each other 
proximity of diamonds to the rosette
Those are the seven traits you need to look at.  Marble basically exaggerates the look of the wild type while reducing black.  For thickness of black.  You want thick black since marble reduces black and the black is what you want the marble to shatter.  
For diamond shape.  You want sharp or hexagonal with straight edges so you get a nice geometric look and avoid striping.
For diamond count.  You want high but if they are not sharp and bleeding into each out you can get striping.
For diamond width.  The wider diamonds will give longer lines to the connecting point.  This means more black to be broken up. But if the diamond is more rounded you can get a striped marble.
For diamond length.  The longer the diamond the more of chance it stripes.
For diamond proximity to each other.  Some space in between is good to avoid striping
For diamond proximity to the rosette.  This isnt much of an issue for marble because of how the marble gene tends to pull the back pattern in tight to the top.  Rosettes width and count will determine if the marble has a solid white stripe down the side or not .  But that a different topic. 

I hope these perspectives on selective breeding and morph manipulation can help.