These days, it's more complex. If you want to become a head, you have to get yourself on one of the National College of School Leadership's training schedules. Just filling in the application form takes weeks.
Headship is harder than ever before, and vast amounts of public money have been invested in creating this massive training organisation, the aim being to turn out higher quality leaders. Nevertheless, stories I've heard make me question whether schools are really getting better heads than they had all those years ago.
Take George, for example, a newly qualified teacher appointed to a city comprehensive with a relatively new head. One morning, after being subjected to serious verbal abuse by a child, George took the boy's arm and gently tried to lead him back to his seat. The boy grumbled, but complied. The next morning George was summoned to the head's room, where he found the boy, his parents, the head and a deputy. The boy had complained that he'd been physically assaulted. George was asked to explain himself - and then suggest better ways he could have handled the situation. All this in front of the child, who was obviously thoroughly enjoying himself. Appalled, George left the school and found a different career.
David also taught in a comprehensive with a new head, but in a leafy London suburb. None of his classroom windows opened properly and there was no air conditioning. One stifling summer afternoon, he managed to wedge one window slightly open. With the door open as well, a draught of air blew through. At that moment, the headteacher happened to walk in and ask why the door was open. David explained how desperate they were for air. "That's hardly the point," said the head briskly. "The policy of the school is to have doors closed. Children are very quick to spot an open door." And out she went, closing the door firmly behind her.
Karen wondered how she managed to obtain a teaching post so easily at a modern primary in a nice part of town. She soon discovered that the head's intolerant, autocratic attitude had caused 15 staff to leave in the previous two years. One teacher who had worked for many years at the school upset the head by refusing to take on yet another curriculum workload for no extra money. She decided to leave, and asked for a reference. The head wrote: "Mrs Andrews has worked here for 16 years. She is punctual and rarely absent." She wrote nothing else on the paper at all, putting the teacher's chances of finding another job in jeopardy. Karen appealed to the chair of governors ... an ineffectual woman who simply said that there was nothing she could do.
But the head I heard about last week really takes the biscuit. The school is chaotic, and she spends most of her time in her room or out at meetings. The staff were desperate for a little support, and now they've got it. She has appointed two assistant heads, on huge salaries, to wander round "monitoring" everybody. It simply beggars belief.
Teaching is about people. And if heads can't even get the basics right, the NCSL will have to move people management skills a lot higher up the agenda.
Mike Kent Headteacher at Comber Grove Primary School, Camberwell, email@example.com.