WCS is a slotted dance the follower travels back and forth along a shoulder-width rectangle, called the slot, with respect to the leader. The leader is more stationary but will move in and out of the slot depending on the pattern led. A general rule is that the leader leaves the slot only to give way for the follower to pass him.

Socially, it is considered good etiquette (particularly on a crowded floor) to use a fixed slot, in order to allow dancing without incident.

There are urban myths regarding the origin of the slotted style. According to one version, it was an invention of Hollywood film makers who wanted “dancers to stay in the same plane, to avoid going in and out of focus”. Wide angle lenses with adequate depth of field for cinematography had in fact been available since the 1920s. A variation on the "Hollywood film maker" theme is that film makers wanted "to avoid filming the backs" of dancers. A viewing of films featuring the work of Dean Collins in the 1940s, and rock 'n' roll films made in the mid 1950s reveals the fact that dancers turn frequently and inevitably turn their backs to the camera. Although another unslotted swing dance, Balboa, became popular in the same area and under the same conditions, much has been made of "jitterbugging in the aisles" as a source of the slotted style.

Slotted moves were a common part of the step vocabulary of Lindy and/or Jitterbug dancers during the 1940s and 1950s. Rather than the walk, walk of West Coast Swing, however, two sets of triple steps were used when the woman moved down the slot, followed by a rock step rather than the current triple and anchor step.