>> Think about it like a multiple-choice test. If you do not know the answer but take a wild guess, you might get lucky and be right. Leaving it blank guarantees a zero. In the same way, when models are graded only on accuracy, the percentage of questions they get exactly right, they are encouraged to guess rather than say “I don’t know.”

For TIMED multiple-choice tests (and the timed constraint makes sense in OP analogy as well), probabilistic answering is the kryptonite that lets smart people do well on SATs and IQ tests and other things like that.

I took an IQ test recently and it all came rushing back to me.

For math problems, often the right answer can be found just by inspecting the ones digit of the possible answers and process of elimination. Others, by abstracting what errors the test writer is expecting you to make, and eliminating those as possible answers. It's like magic. Sure, you could actually sit and SOLVE each problem, but when spend the time, when time is valuable?

Pretty sure these types of strategies are not actively taught to anyone unless you have a good college counselor /interested teacher/ SAT tutor. But perhaps they ought to be.

Yeah when you realize that the fake answers to the test have been created by humans, you can predict what false answers might look like - you can even get a feel for the kind of false answers that the test’s author tends to provide, and by the end of the test you can start to spot them fairly confidently. You still check your work, obviously, but it’s like picking up on a poker player’s tell - it gives you an edge.