The purpose of the Foundation Quarter Horse Registry is to preserve, protect, and perpetuate the working cow horse bloodlines of the Foundation Quarter Horse by the individuals that the FQHR deems as Foundation bred. The Registry is based on blood.
The American Quarter Horse Association was organized in 1940 with similar intent. Therefore the Foundation Quarter Horse Registry recognizes those horses listed in the first five studbooks (first 27,000 horses registered) as Foundation bred.
Most horses carrying 75% Foundation blood are eligible for registration. The fourth generation is critical (great grand sires and great grand dams), of that generation 75% should descend from or run to Foundation blood. No registered thoroughbred may be closer than the fourth generation.