For teachers, the authors of “Practice Perfect” write, pregame repetition is crucial. “If a teacher’s performance during a given class is less than what she wanted, she cannot get it back,” they say. “She cannot as, say, a lawyer working on a contract might do, stop in the middle of her work and call someone to ask for advice. She can’t give it her best shot and then, as we are doing as we write this book, go back and tinker and revise and have the luxury of being held accountable for a final product that reflects actions taken and reconsidered over an extended period.”

“If we asked a roomful of teachers how often they practiced what they did in the ‘game,’ that is how often they rehearsed the questions they’d ask or the way they’d start class, most would look at us funny,” the authors say. “Teachers listen, reflect, discuss and debate, but not practice.”

The authors learned this only recently after analyzing the results of a study of great teachers in high-poverty public schools, reported in Lemov’s previous best-selling book, “Teach Like a Champion.” The teachers with the best results “were often the most likely to focus on small and seemingly mundane aspects of their daily work.” The authors liken this to legendary basketball coach John Wooden, who went so far as to teach players how to put their socks on correctly. But the insight did not immediately illumine the importance of practice.

As part of the Uncommon Schools charter school network, the authors began to train their teachers with video clips of skilled instructors performing a given technique. The trainees discussed and analyzed until they were sure they understood it, then moved on to the next technique. They left the class full of confidence, but when surveyed three months later were not so sure. Something often went wrong when they tried the techniques in class.

The authors realized their trainees hadn’t practiced. It was the equivalent of trying to learn a new backhand in the middle of a match at Wimbledon’s Centre Court.