SAT · Guessing
Should you guess on the SAT?
Yes, on every question, without exception. The reasoning takes one line: a wrong answer and a blank are both worth zero, so a guess cannot cost you anything and might gain you a mark. What follows is what that is worth in practice, and why the advice is not universal.
SAT guessing strategy: the arithmetic
Every SAT question with four options gives a blind guess a one in four chance of being right. A correct answer is worth one raw mark and a wrong one is worth nothing, so the expected value of a blind guess is 0.25 marks.
| Options you can rule out | Chance of being right | Expected marks |
|---|---|---|
| None | 1 in 4 | 0.25 |
| One | 1 in 3 | 0.33 |
| Two | 1 in 2 | 0.50 |
| Three | certain | 1.00 |
Every row is positive. There is no point at which guessing becomes a bad idea, and eliminating even one option raises the return by a third.
Across the fifteen questions a candidate might otherwise leave blank in a full test, blind guessing is worth roughly four raw marks. On the reported scale that is often forty to fifty points.
Running out of time on the SAT
If the clock is running out, fill in every remaining answer before it does. Do not read them. Do not try to pick well. An answer chosen at random is worth 0.25 marks and a blank is worth zero, and the difference across ten questions is two and a half marks for a few seconds of work.
The testing application shows which questions are unanswered, so this takes less time than it sounds.
SAT penalty rules against other entrance tests
Some entrance tests deduct marks for wrong answers, and on those the arithmetic reverses.
CEnT-S, used for English-taught degrees at Italian universities, has five options and deducts a quarter of a mark for a wrong answer. A blind guess there is worth one fifth of a mark gained against four fifths of a quarter lost, which comes to exactly zero. Guessing blindly is neither good nor bad, and it only becomes worthwhile once an option can be ruled out.
A candidate preparing for both tests has to hold two different rules, and the SAT rule is the one that gets forgotten, because "when in doubt, leave it blank" is the advice that circulates most widely. It is wrong here.
Guessing well on the SAT
None of this argues against thinking. A guess after eliminating two options is worth twice a blind one, so the elimination is worth the time if the time is there.
Two habits help. Read every option before choosing, because the SAT often places a plausible answer before the correct one. And when two options say nearly the same thing, neither is usually right, since a question with two correct answers would not have survived pretesting.
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