In professional sumo wrestling, an ichimon is a grouping of stables. Because of their specific nature, clans are also sometimes referred to as the sports equivalent of a traditional family or a commonwealth. Every stable must be affiliated to one of the five existing clans. In the past, the clans were close-knit, but this bond has weakened with time and the reforms of professional sumo. Nowadays clans serve primarily as political factions. Elders' ambition has also caused some clans to splinter, turning a cohesive landscape into a fragmented one. Of the clans founded during the Edo period, none remain today. Of the five current clans, not all enjoy the same aura or influence within the association. For example, the Dewanoumi and Nishonoseki clans each have more influence than the three smallest clans combined. The powers of the various clans have also evolved with the association itself.