An autocrat himself is not rigging things, he assigns tasks to various people and holds them to account. For them it's safer to err on the side of caution, and

An autocrat himself is not rigging things, he assigns tasks to various people and holds them to account. For them it's safer to err on the side of caution, and for him it's better to reward the over-achievers than to be seen cutting slack to the under-achievers.