[broiler]

It really depends on what section he has left to pass. A good trick is to see if he knows anyone that has taken that section in this testing window. Our staff in the office have found a frequent similarity in the major topics covered on a section in the same testing window, ie the tax questions a few months ago had an unusually high focus on AMT. The questions might even be the same because some of the areas just don't have a large database of questions when the importance gets turned up.

TR has the right idea that he should only focus on the major topics. There is no reason to focus on the smaller topics. If he gets a really obscure section, he would have been wasting time by studying all of the obscure areas to know the answers to a small subset of questions. The only possible downfall to this strategy is that the random question generator may cause you to get a bunch of obscure questions and you just have to live with that as a possibility.