Dominant gokenin who assumed the post of shoshi (Deputy Chief of the Board of Retainers) or Samurai-dokoro no tsukasa (the officer of the Board of Retainers) controlled Samuraidokoro, and the person in the highest rank among shoshi was called betto (chief officer).
所司（しょし）または侍所司（さむらいどころのつかさ）と呼ばれる役職についた有力御家人が統制し、所司の中で最高位の者は別当（べっとう）と呼ばれた。