Talk about IFR holding patterns in a recurrent training setting and your time will most likely be spent discussing entries, maximum speeds and mandatory reports. There is a need created by the realities of the system for ATC to park you somewhere in the sky until it is time to move on. The reasons for being placed in a hold and held there normally boil down to one of three things: weather, traffic or an abnormal ATC situation.
This is a companion discussion topic for the original entry at https://www.avweb.com/flight-safety/technique/pointless-ovals-in-the-sky