Knowing how to guess intelligently on the SAT is a critical part of maximizing your SAT score. Of course you’ve learned stuff in school that will definitely help you on this test, like how to read actively, think critically, and whip out that quadratic formula song. This “content knowledge” is your intellectual foundation for this test, but there’s a limit to that knowledge and it’s different for every person. What if you’re stuck on a problem, and you’ve ruled out two answer choices by process of elimination? Should pick one of the remaining answer choices and just guess? Or should you “play it safe” and skip the question, wasting all that hard work and time you spent trying to answer it? This is where strategy knowledge comes in handy – knowing a few good tricks and just understanding how the test actually works.
Guessing intelligently is one of those key strategies. The big question is… when to guess? Let me show you.
Scenario A: Suppose you’re guessing cold on five questions. You are unable to eliminate any answer choices at all (An awful idea, as I’m sure you’re all thinking.). The probability of guessing the correct answer in Scenario A is one out of five. Thus in five tries, you’d likely get one answer right and the others wrong.
Now, remember how the College Board scores multiple choice questions? You earn one point for every question you answer correctly and lose a quarter point for every question you answer incorrectly, while neither earning nor losing any points for not answering, or skipping, a question. In this scenario, you’d earn one point for the correct answer and lose a quarter point for each of the four incorrect answers (a total loss of one point), for a net profit of zero points.
In the long run, you haven’t earned any points, but you haven’t lost any either, right? WRONG. You have, in fact, lost a lot of points; you’ve wasted precious time cold guessing on these five questions when you could have spent that time earning points on other questions that would be easier for you. Well shucks.
You may of course get lucky and earn a few points this way… but it’s equally likely that you’ll be unlucky and end up with a negative net score. Gross.
Bottom line? Cold guessing is never a reliable way to answer questions. Never cold guess.
Scenario B: Suppose you’re now able to eliminate with certainty exactly one answer choice on the next four questions; the probability of guessing the correct answer here is one out of four times. On four such tries, you’d expect to guess correctly once, earning one point, and incorrectly three times, losing a total of 0.75 points.
Your net profit is a measly 0.25… after answering four questions! That’s just .06 points per guess. You’re still spending a lot of time on these questions, and, on average, earning very little in the process. Even though you might get lucky with a few of these guesses, there’s also a chance that you won’t. This is clearly not worth it.
Bottom line? Guessing after eliminating only one answer choice is also a bad idea.
Scenario C: Suppose you’re able to eliminate with certainty exactly two answer choices on the next three questions. Here the probability of guessing the correct answer is one out of three times. In Scenario C, you’d probably guess correctly once, earning one point, and incorrectly two times, losing a total of 0.5 points.
Your net profit is 0.5 points… after answering only three questions! That’s about 0.17 points per guess now, which is THREE TIMES better than Scenario B! This isn’t a huge net profit, but it’s pretty good insurance against having bad luck at guessing. The potential reward has now become worth the risk aka time cost.
Bottom line? Guessing after eliminating two answer choices is a good idea.
Scenario D: Suppose you’re able to eliminate with certainty exactly three answer choices on the next two questions. The probability of guessing the correct answer here is one out of two times. In Scenario D, you’d likely guess correctly once, earning one point, and incorrectly once, losing 0.25 points. Now you’ve got a net profit of 0.75 points in only two attempts. That’s an average of 0.38 points per guess., more than TWICE as good as Scenario C, which was already looking pretty fine.
Bottom line? Guessing after eliminating three answer choices is a very good idea.
Conclusion: You’ve seen me do the math. Guessing is a good idea if you can eliminate, with certainty, at least two answer choices. Even if the uncertainty of guessing makes you uncomfortable, good luck will balance out bad luck more often than not.