Many Apollo engineers, later to become top managers, considered Kraft to have been one of the best managers in the program. He personally hand-picked and trained an entire generation of NASA flight directors, including John Hodge, Glynn Lunney and Gene Kranz, the last of whom referred to Kraft simply as "The Teacher".[55] In the words of the space historians Murray and Cox, Kraft "set the tone for one of the most striking features of Flight Operations: unquestioning trust — not of superiors by subordinates, but the other way around."[2]