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# Decrease and Increase

Do ratings in Brilliant decrease faster than they increase?

What I mean to say is, do the ratings increase when we solve the problems correctly and decrease when we make a wrong attempt at the same rate?

It feels like they decrease faster................. it may be wrong because I haven't kept a track of my ratings since a long time.

Note by Maharnab Mitra
3 years, 6 months ago

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There are several confounding variables involved in the calculations, when you attempt to ask a question like this. The main consideration is your correct to wrong ratio, as there is a trade off between "being right most of the time" and "a favorable reward:penalty ratio".

If you find that you are correct 5 times and wrong 5 times, then your relative rates of rating increase and decrease will be the same. However, because we tend to show you problems which you are much more likely to solve, if you are correct 7 times (say with a rating change of + 20 each), then when you are wrong 3 times, the rating change will have to be $$-\frac{ 7 \times 20 } { 3} \approx -50$$.

This is further impacted because you have the ability to choose when to answer, and many people do not answer if they have no idea. The higher your solve rate, the more drastic the reward:penally ratio will appear. Conversely, if you make the decision to only solve hard problems, and are willing to have a solve rate of 30%, then it would appear that you are greatly rewarded for getting a problem correct.

There are of course numerous other factors involved, like psychological remembrance of pain vs forgetting the gains, and that being correct on the second and third tries do not award you as great of an increase. Staff · 3 years, 6 months ago

i think so, i once accidentally typed 309 instead of 308 and my rating fell down terribly; and it didn't increase quite so much when i typed the correct answer. · 3 years, 6 months ago

If you were right on the second try, then your net rating would (almost surely) have increased. This means that the gain would have to be more than the loss.

Note that the net gain of being correct on the second try, is less than being correct on the first try. For someone with 10 correct (on first try) + 10 wrong (only 1 try), their net change in rating will be much larger than someone with 10 correct (only on third try), and 10 wrong (all 3 tries wrong). In the latter, the net rating change would likely be negative. Staff · 3 years, 6 months ago