To research todays contemporary pedigrees when searched upon thoroughbred evolutionary breeding phrases challenges one’s optimism.
The considerations I apply to pedigrees has altered, as over a course of time – (new) sires and the breeding broodmare population vary accordingly through generational cycles.
The breeding thing called ‘genetics’ are never dialled-on-call, nor are they ever fixed. Genetics arrive from 5th-7th infusions, thus the genetic ‘adaptation’ or variation, is really the natural process-in-time.
Yep, you can’t change Nature and she knows ‘finer’ direction, – its jumping DNA.
The evolutionary breeding phrases WILL provide fair assumption of what has rightful inheritance towards quality thoroughbred & its sustainable future. Rightful inheritance those who ‘transmit’ quality. Not to diffuse, & that which may even confuse consolidation of female bloodlines.
Better effort is to arrive at ‘traits’ or the ‘strains’ within, (for genotype dominance) rather than through solely emphasizing that racing individual, upon its merits. 
- Princequillo male lines (forward & back) come very high on radar.
Whilst stating the obvious, global commercial male lines now tail to Nearco.
Who would think we are almost saying goodbye, see ya forever, to likes of staying fabric Hyperion, the dam Selene, her female family, the Southern Hemisphere amazing sire Sir Tristram, his grandson Might and Power (also ‘Selene’)
The election of Princequillo to the position of Supreme Dominator, under scientific classification of genetic merit, leads the provocative but reasoned assertion that Princequillo’s influence on the creation and shaping of the towering prepotency of Sir Tristram could be struck several percentage points of ‘transcendence’ high. credit: Ross du Bourg.
How is it Hyperion, with Princequillo male lines is almost at an non-existent state?
How will young, speedy colts as commercial sires produce another???
Paradoxically new ‘roads less travelled’ may lay with the female/broodmare.
You may want to reflect… latest blog diamond in the rough
That good breeding is now forced to seek deep. Funny, how one opportune trait makes a pathway ‘correction’ within superior pedigree. That trait is structural/constitutional: not always about speed or stamina ability but another.
*It is a pity that through human sin much good material is wasted which was destined by Divine Nature to be chosen material.
The knowledge that sham is easier and cheaper to produce than the real thing, and the fact that there are still people enough who are deceived by sham, has just as much a deteriorating influence in the producing of wine, and other things, as in the breeding of horses. The craftiness of the breeder to produce showy stock very cheaply has often made greater breeding progress than the expert knowledge of the consumer.
HORSE BREEDING (IN THEORY & PRACTICE) B. Von OETTINGEN (1909)
Tough traits are extraordinary survivors, adaptors.
Littleprincessemma – the dam of American Pharoah (older blog) – American Pharoah pows a ‘Grand Slam’ clearly exhibited 3x key-strains/traits belonging to that of Olympia (USA), dam Miss Olympia – female family 4-P. With references @ Mit. DNA identify heritage as Regulus mare.
(side-note: Chasing Yesterday, chestnut filly 5 starts, 4 wins – by Tapit, from Littleprincessemma, where Tapit’s key strains to female family 13-C i.e. Mr Prospector/Seattle Slew/Le Fabuleux (FR) take heritage to Regulus mare. )
We find harmony of genetics works stronger than the sex-balancing towards few, major-players of the pedigree. What we mean is to find (at best) genus, the bloodlines which we may assume has truer genotype.
The more composing harmony of the genetics, comes bio-mechanics/structure/ability.
It’s back to school, knowing basics, by these terms, as written from The Australian & New Zealand Thoroughbred – Ross du Bourg – whose complete work, lives on….
gene: the unit of inheritance transmitted by the chromosome
genotype: the fundamental hereditary constitution of an organism; the genetic formula of the organism.
homozygote: an organism that contains two identical genes for the same characteristic, and hence will breed true for that characteristic if mated with an organism similarly homozygous for that characteristic.
heterozygote: an organism that contains two dissimilar genes for the same characteristic, and there will not always breed true to type.
prepotency: the ability of one parent to impress its hereditary characteristics on its progeny because it has more homozygous, dominant or epistatic (the gene which determines whether a trait will be expressed. One parent is prepotent when it consistently outperforms its partner in transmitting critical racing characteristics.
Cheers for now 
n.b. Birkhahn strain held to Galileo 
Essentially, bloodlines 
English