The Walk is one of the two gaits that are rarely excellent in the PRE Andalusian horse. PRE sport horse breeders are working hard to change this, but it is a long and hard journey.
After being used originally as a war horse, and for hard and dangerous work with the bulls in the vast open fields, Spanish horse owners started using their horses for fiestas, carriage driving and parades. An expressive trot with high knee actioned was considered pretty, so breeders concentrated on developing the trot, more or less to the exclusion of the others.
Therefore, the trot in most PRE Andalusians is most often rated anywhere from decent to excellent, while the walk and canter can be disappointing from a sport horse point of view.
In this photo Fer Bulería in a training session at Villa Equus. He has a 100% correct, very long and relaxed walk. He typically transmits the walk to his offspring.
Photo Credit: Enrique de Benito