Stephen Covey once told the story of a steel mill manager who wrote "6" on the wall when the night shift was leaving.
That prompted the day shift to improve their result.
In "Bringing out the best in people" by Alan Loy McGinnis the name of the manager is given.
That name is: Charles Schwab!
I was excited to note this, because I have recently stumbled upon Schwab's name several times in different contexts.