<p>The kind of difficult stuff you are probably thinking of is never on the SAT. (Like: what is the probability that you have a certain disease given that you test positive…) </p>
<p>Let the Blue Books be your guide. If you have not seen a concept tested there, it is not likely that you are going to see it on your test. The topics covered evolve slowly – any major change (like including topics from Algebra II) is always announced well in advance. For example, when they added Algebra II, they were pretty specific. They said there could be problems where trig was possible but not required. So you are not going to suddenly need Bayes Theorem with no warning.</p>