"What I am attempting is to prepare the reader for the conclusion that there is no conclusion to the study of pedigrees." J. A. Estes, former editor of The Blood-Horse
Pedigree refers to a horse's family tree, with its paternal ancestors -- sire/father -- on the top, and its maternal ancestors -- dam/mother -- on the bottom. A horse's pedigree provides insight into its potential ability and value.
A few basic points to consider from among the numerous facts and attributes regarding a sire are number and size of foal crops; percentage of progeny that are starters, winners and stakes winners; type of horse the sire produces: turf or dirt, sprint or route; precociousness of his foals -- does he produce better 2-year-old runners or do they develop more slowly?; and age of the sire -- some people believe the horse's ability to pass on desirable traits diminishes as he gets older.
As with a sire, there are many factors to consider with regard to a dam. Such factors to consider are racing and produce record of the female side, going back at least two generations; performance of her foals on the track -- how many made it to the track and started? What was their race record, i.e., number of starts, wins and purse money earned? How long did they withstand training?; and number of full and/or half-siblings that have been stakes performers.
There are as many theories about pedigree as there are theories about how to make money in the stock market. For example, some pedigree consultants pay particular attention to in-breeding and out-crossing, while others elect to focus on the physical or performance characteristics of the horse. Because beliefs differ so greatly, you should be as familiar with as many as you can, and select those theories you find most appealing.