Negative Marking: When Guessing Helps in SSC CGL, IBPS PO and RRB NTPC (with the Maths)
Should you guess? The exact break-even accuracy for SSC CGL, IBPS PO and RRB NTPC, what eliminating one option is worth, and when to skip.
Updated 27 October 2026· 6 min read
"Should I guess or leave it?" has a real answer, and it is different for each exam. It depends on two things: how much a wrong answer costs, and how many options you can rule out.
The marking in each exam
| Exam | Right answer | Wrong answer | Options |
|---|---|---|---|
| SSC CGL Tier 1 | +2 | −0.5 | 4 |
| IBPS PO Prelims | + marks for the question | −¼ of the question's marks | 5 |
| RRB NTPC CBT 1 | +1 | −⅓ | 4 |
The break-even point
A guess is worth taking, on average, when your chance of being right is above the break-even point. You reach it when the expected gain equals the expected loss.
| Exam | Guess helps if your chance of being right is above |
|---|---|
| SSC CGL | 20% |
| IBPS PO | 20% |
| RRB NTPC | 25% |
For SSC CGL: if p is your chance of being right, the expected marks are 2p − 0.5(1 − p). That is above zero when p is above 0.2.
What eliminating options is worth
The table shows the average marks you gain per guess, for each question.
| Options left | SSC CGL (out of 2) | IBPS PO (per mark) | RRB NTPC (out of 1) |
|---|---|---|---|
| All (blind guess) | +0.13 | 0.00 | 0.00 |
| One ruled out | +0.33 | +0.06 | +0.11 |
| Two ruled out | +0.75 | +0.17 | +0.33 |
Three things stand out:
- In IBPS PO and RRB NTPC, a blind guess is worth exactly nothing on average. It only adds risk.
- In SSC CGL, even a blind guess is slightly positive, because a wrong answer costs only a quarter of a right one. But +0.13 marks is tiny, and it costs time.
- Ruling out two options changes everything. In every exam, a 50:50 guess is clearly worth taking.
Why "average" is not the whole story
These numbers are averages over many guesses. On a single paper, ten blind guesses can easily go badly. And guessing has two hidden costs:
- Time. In SSC CGL's 15-minute sections and IBPS PO's 20-minute sections, the minute you spend on a guess is a minute taken from a question you could solve.
- False confidence. Most aspirants overrate how sure they are. A "70% sure" answer is often right only half the time.
A simple rule
- Answer what you can solve.
- Guess when you can rule out at least one option (two for IBPS PO and RRB NTPC).
- Skip the rest, quickly.
Check your own guessing in mocks
Your mock reports can tell you whether your guesses pay. Mark the questions you guessed, and after the test compare the accuracy of your guesses with the break-even point above. RankVyuh's report shows how many marks you lost to wrong answers in each section, and which wrong answers were rushed (answered much faster than your usual pace).
Frequently asked questions
Is guessing worth it in SSC CGL?
On average, yes, if your chance of being right is above 20%. A blind guess among four options gains about 0.13 marks on average, and ruling out one option raises that to about 0.33 marks.
Should I guess in RRB NTPC?
Only if you can rule out at least one option. With −1/3 per wrong answer and four options, a blind guess gains nothing on average.