hiddenanonymous's blog

Regarding Rating Change of the Recent contest #789
By hiddenanonymous, 3 years ago, In English

Is the rating predictor not working correctly or is the rating assigned wrong? For some, it deviates a lot in the negative direction, for some a lot in the positive direction and for some, it approximately matches with the predictor. Can someone please explain why is it occurring? In the previous contests, it had just the error of +- 5, now it's deviating a lot in both directions.
MikeMirzayanov can you please give any update, if it's a mistake from your side or not? These deviations I am seeing for the first time, and even some months back, there was a mistake in assigning the ratings.

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3 years ago, # |
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Carrot had a pretty good prediction compared to CF-Predictor for me.

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    3 years ago, # ^ |
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    I use both, you can compare from the previous rounds, CF-Predictor almost predicts correct rating with an error of +-2, while Carrot has more error. In this contest only, rating changes are deviating a lot and even it's not the same for all the users. Just compare the ranks 96 in Div2, there are two users, for ChenHuaXin, rating predictor: +154 (actual: +156) and for YL-9, rating predictor: +106 (actual: +94). There are more such examples, generally what happens, if the rating predictor says +10 (let) and the actual change is +12 (let), then that 1-3 difference will be for all the users.
    I think there is some issue with the rating change this time, as it happened some months back.

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      3 years ago, # ^ |
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      Can you explain how to use CF-rating predictor ? idk how to use it

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        3 years ago, # ^ |
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        To use it you should be doing CF on a Google Chrome. If you do so: https://chrome.google.com/webstore/detail/cf-predictor/ocfloejijfhhkkdmheodbaanephbnfhn.

        There you install said extension and nothing more needs to be done. After successful installation you will see an approximate change in points for anybody you want in a "standings" section for each contest (if you follow the above link you'll see a picture with an example of how it will look like, the rightmost (delta) column is responsible for showing an approximate rating change).

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          3 years ago, # ^ |
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          My mistake, I knew about this extension, actually I wanted to know how to use virtual rating predictor from this website : https://cfviz.netlify.app/virtual-rating-change.html

          And how much accurate is this virtual rating predictor ?

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            3 years ago, # ^ |
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            For me for the last contest it is 20 points difference between a prediction and real points change. As for me that inaccurate at all.

            To check it yourself: in the first "contest ID" field you put a number that you can see at the end of URL for a particular contest. Then you put your points from standings from a "=" column in a "points" field. After you put your CF name (handle), amount of penalties you had in a contest (0 if none). And then you fill the last section with your previous (old) rating.

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