by how far they are from the cantle to the fork. Placement of the front rigging is a critical component of western saddle design. The closer the rigging is to the center of the saddle, the more the rider will be balanced over the horse's center of balance, allowing freer movement and agility of horse and rider. On the other hand, the more forward the rigging is set, especially when combined with a back cinch, the more the saddle will set down on the horse, placing the rider a bit behind the horse's center of balance, but creating greater security. Full rigging refers to the most forward position, where the front cinch ring is placed located under the center of the fork or swells of the saddle. Spanish settlers of North America originally used full rigging, but without a back cinch, this type of rigging was a disadvantage because the saddle would rise in the back while traveling over rough terrain. Center fire is the rigging design placed closest to the center of the saddle. Historically, it replaced the full rigging. Center fire rigging is located halfway between the cantle and the fork and was always single-rigged. This type is rarely seen on western saddles today, but was used during the 1800s, and notably on the McClellan saddle of the U.S. Army. The Pony Express saddle also had center fire rigging. Modern saddles also use two additional positions, called "seven-eighths" (written 7/8) and "three-quarter" (written 3/4). 3/4 rigging is located three-quarters of the way from the cantle to the fork; thus halfway between center fire and full positions. 7/8 rigging is 7/8 of the way from the cantle to the fork; or halfway between 3/4 and full. Three-way rigging utilizes various designs of multi-position cinch rings to combine the Full, 7/8 and 3/4 positions in one piece of hardware. Full position is achieved when the latigo is attached to the front ring. 7/8ths position has the latigo attached to both the front and the back ring, and the 3/4 position has the latigo attached at the back ring. Flank cinches were added after the rodeo sports of calf roping and team roping became popular. The flank cinch was added in order to keep the saddle from tipping in the back when a lasso was tied or dallied to the saddle horn. As a result, the 3/4 and 7/8 front rigging