Test taking skills

On the way from work, I congratulated him again on his AP scores.  He and several of his academic team members work together this summer and they all learnt about their AP results today, and they  shared their scores with each other at lunch hour. In the car, he said,  Jack, one of  his friends, is much more knowledgeable about  World History  than he is, and knows how to articulate it exceptionally well. Jack got a 3 in World History, which does not seem to be fair to Jack.  

My passenger summarized that, unlike Jack, he is a good test taker,  he is able to pick it out what concept or structure the examination tries to test about.  I have always heard about some people are good test takers, I do not know that I have one close by. It is a good skill to have, yet he needs to study more about the real knowledge.