Some courses and tutoring programs teach you to omit the last few problems in each section that is in difficulty order based on your expected score. This means all sections except the critical reading passages and writing problems 30-35. For example in a math section with 20 problems, if your expected score is 450, you might omit the last 6 problems, 500 5 problems, 550 4 problems, 600 2 problems, and 650 1 problem. For the new SAT, of course you would need to guess those problems randomly. If you are > 650, then answer all problems. I feel this approach is useful in giving the student more time if properly implemented.
It’s useful based on the expected scores you posited.
Not as helpful as learning to increase the scores through answering more questions correctly though 
Omitting questions is a pretty dumb strategy, tbh. The Collegeboard purposefully makes a wrong answer a .25 point penalty from your raw score, because that makes you break even. In a group of 5 multiple choice questions with 5 answers each, if you guess randomly on all 5 of them, you’re more than likely to get 1 out of the 5 questions right. That gives you 1 raw score point for those 5 questions. if you guess the other 4 completely wrong, then you’re penalized 4 x .25 raw score points = 1 raw score point, so you gain 0 points from those 5 questions, which is the same as if you omitted all 5 questions. HOWEVER, on the vast majority of questions, you narrow down an average of at least 2 answer choices, giving you a better chance at guessing the question correctly. So, guessing yields more raw score points than omitting answers.
tl;dr
never omit. always have an answer for every question.
Well, I am one who advocates this method as a realistic way of getting an efficient score boost. I wrote about it in my book and I distribute the advice freely in chart form here:http://www.satgameplan.com/satcharts/satchartframe.htm and I promise that I have seen this advice work successfully hundreds and hundreds of times.
Obviously, you get an 800 by answering all the questions. But 800 is not a realistic goal when your last practice test was a 600 and the test is in two weeks. For most mortals, going slow and answering only what you get to and what you need for your next score goal is the rational plan. Just looking at the 1/4 penalty is not enough to design an optimum plan. The test is more subtle than that (as are the rules of CONDITIONAL probability). Effective use of time is key.
Now, on the new test, the game is going to change. I am waiting to see actual released tests to make an official strategy recommendation, but I expect that careful, slow work on problems of the appropriate difficulty level will still be a good plan. But leaving blanks will not be part of the plan starting in March.
Another possible problem with automatically omitting the last few problems is that #20 could be very easy (to you) but #14 or #15 might not.
^ Right. So if you are at say, 650 or better, an optimum plan involves slow careful work through the first 15 and then opportunistic scanning of the last 5.
Of course, you are likely to be better at that scanning after you have thoroughly mastered REAL blue book tests. This is yet another way that fake tests fail to give good return on time invested.
True
the only practice tests that are actually accurate and indicative of the types and difficulties of questions on the real SAT are those released/published by the CB itself. obviously, if you want more, the next best tests are big name test-prep companies’ tests, namely PR and possibly barrons.
Obviously, guess randomly the last questions with the new SAT.
It is marginal with most students I work with, who are at 600+ when done with lessons. However, if a student is at 450-500, it makes no sense to answer all the problems. You waste time and fall into attractors if you try.
You might change your mind by taking two tests and applying the different methods.
The statistical theories are based on random guesses, which DO not apply to the SAT testers. Wild guesses and erroneous guesses are a killer on the SAT. When a student does not know the answer, chances are that he did not do too well on the exclusion process. It is not unusual for students to reject the correct answer in the CR section because of missing the question or not being concentrated. He then guesses between … incorrect answers.
On the other hand, students who shoot for a particular score might be well-served by studying the score chart and consider the cost of omitting the “expected” Level 4 or 5 questions. It pays to know what it takes to score 600 in each section.
The only time I’d advocate to rely on guessing is when a student is very (very) close to a perfect score and looks at the last 1-2 questions. With one mistake, the penalty disappears. Also, one can freely guess on the SPR but with little hope!
There is a reason why TCB recommended guessing! Think about it!
PS With the number of official tests that have been released, there is NEVER a need to waste time on the PR or Barrons’ tests.