Negative marking in NEET: when a guess is worth it

Summary: Under +4 and minus 1 with four options, a guess breaks even when your chance of being right is 1 in 5. If you can confidently eliminate two options, guessing is clearly worth it; with one option eliminated, it is worth it on average; a blind guess gains very little and carries real risk. The catch is that NEET distractors can make your true chance lower than it feels.

The marking scheme

In the 2026 bulletin, each correct answer earns +4, each incorrect answer costs 1 mark, and a question left blank scores 0. Each question has four options with one correct answer. Confirm this in the bulletin for your year, because the rest of this page depends on it.

Expected value in one line

Expected value is the average number of marks a decision gives you if you made the same decision many times. For one guess with a probability p of being right:

Expected marks from a guess = 4 × p − 1 × (1 − p) = 5p − 1

Leaving the question blank always gives 0. So a guess is worth it on average whenever 5p − 1 is more than 0, which means p is more than 1/5, or 20%.

That single number is the key to the whole page. Any time you believe you have better than a 1-in-5 chance of being right, the average says guess.

Worked examples

On averages alone, even a blind guess comes out slightly positive. That surprises many students. Before you decide to fill every blank bubble, read the next two sections.

Averages hide the risk

An average is what happens over many repeats. You sit NEET once. So it helps to ask a second question: what is the chance that a set of guesses leaves me worse off than leaving them blank?

Ten blind guesses. You need at least 2 correct out of 10 to avoid losing marks (2 correct and 8 wrong gives 8 − 8 = 0). With a 25% chance on each, the probability of getting 0 or 1 right is about 24%. So roughly one time in four, ten blind guesses cost you marks, and the average gain when things go well is only 2.5 marks.

Ten guesses with one option eliminated. The chance of ending up negative falls to about 10%, and the average gain rises to about 6.7 marks.

Ten guesses at 50-50. The chance of ending up negative is about 1%, and the average gain is 15 marks. At this level, not guessing is the expensive choice.

At the top end of NEET, where thousands of students are separated by a few marks, 15 marks is a large jump in rank, and 2.5 marks with a one-in-four chance of going backwards is a poor bet.

Why your "50-50" may not be 50-50

The weak point in all of this is your estimate of p. NEET options are written to trap students who half-know a topic. A common pattern is a statement question where two options are clearly wrong and the remaining two differ by one word from NCERT. A student who does not know that word is not at 50%; they may be drawn to the wrong option more often than the right one, because the wrong option was designed to look familiar.

Two checks help:

• Did you eliminate options for a reason you can state? "Option B is wrong because the SA node is in the right atrium" is a real elimination. "Option B feels odd" is not.
• Are you choosing between the remaining options on knowledge or on familiarity? If the only reason for your choice is that a phrase looks like something you read, treat it with suspicion.

Test your own calibration in mocks. Mark every guessed question with a small symbol before you check answers. After five mocks, count how many of your "50-50" guesses were right. If it is close to half, trust your eliminations in the exam. If it is closer to a third or less, be stricter.

The tie-break adds a small cost

In the 2026 bulletin, after Biology, Chemistry and Physics marks, the next tie-breaker was the number of incorrect answers: the candidate with fewer wrong answers ranks higher. With lakhs of candidates, ties on the same total are common. So among students with the same score, the one who guessed wildly is ranked below the one who did not. This is a small effect, but it is one more reason to avoid blind guessing.

A decision rule for the exam hall

Apply the rule in round two, after all the questions you can solve have been answered. Guessing decisions should never take time away from questions you can do properly. For how round two fits into the paper, see our 180-minute time plan, and for the full marking scheme see NEET UG exam pattern and marking scheme.

Accuracy beats guessing

Guessing well is worth a few marks. Removing careless errors is worth far more: a single question you knew and got wrong costs you 5 marks compared with getting it right. When you analyse a mock, count careless errors before you count guesses. Timed practice on real papers helps with both, and our previous year papers section gives you an analysis after each attempt.

Common questions