The American Quarter Stock Horse is a subtype of the American Quarter Horse. It is famous for its agility, speed, and cow-sense, which make it, together with the American Paint Stock Horse, the best breed for working cows and performing in various Western-riding disciplines.

The ideal Western horse:
Ever since the 17th century, when the American Quarter Horse breed was created, it was bred for its speed. In the 19th century American Quarter Horses were also bred for their agility as well as for their cow-sense and ability to work cows, which means their ability to predict what cattle are likely to do and compensate for it. These three traits are at the heart of the breeding of American Quarter Stock Horses, who express them to perfection.

The breeding of American Quarter Stock Horses revolves around their performance as Western horses, especially in, but not limited to, the fields of reining and cutting. Furthermore, some breeding lines generate horses which excel in only one Western discipline, but which perform in this event at the highest level.

Performance metrics:
The following are the: range, average, (SD), and MOE of performance metrics of ordered American Quarter Stock Horses in Horse Isle (not bred ones). In rare cases, horses might have metrics outside of the range. Breeders can produce horses that are beyond this range.

Speed: 15.8-17.6, 16.7 (0.3), 0.07.
Sprint: 73-88, 81 (4), 0.72.

Accel: 1.13-1.40, 1.26 (0.04), 0.01.
Decel: 1.04-1.25, 1.16 (0.04), 0.01.

Jump: 5.02-5.31, 5.17 (0.06), 0.01.
Pull: 2.63-3.45, 3.12 (0.18), 0.03.

Turning: 68.79-84.80, 75.93 (3.86), 0.76.
Reverse: 3.0-3.8, 3.4 (0.2), 0.04.

Stamina: 54.53-60.45, 57.51 (1.31), 0.26.
Reaction: 0.79-0.90, 0.85 (0.02), 0.00.

Coats & Height:
Colors: all colors except for dominant black.

Additionals: flaxen, linebacked, minimal-mealy, rabicano, roan, sooty, all rare patterns. The coat is always solid.

Height: 14hh to 16.2hh.