It is my understanding that staff chiefs are for the most part self assigned at their discretion, there are a host of factors that may initiate the response of staff chiefs. They TYPICALLY respond on multiple alarms fires as early as significant 2nd alarms or other significant fires/incidents based on safety, rapid escalation, duration, intensity/scale ,casualties, damage, etc..... . I think 3rd or 4th alarm requires the borough commander or city wide tour commander if not already assigned. Staff chiefs rotate as the the daily on duty city wide tour commander. Any major event you are bound to see multiple staff chiefs respond.At what point are staff chiefs called, above a division, to an incident? And do they rotate being on-duty/call?