hxu10's blog

So many "Fake" newbies in the contest
By hxu10, history, 3 years ago, In English

The codeforces round #765 is over, among the top 10 rated users, 5 are newbies, 2 are specialist. Ranking are as below. rankings

If you click on these newbie users, like the 3rd place @Alan_boyfriend, you can see the user previously take part in round 764 and rank 1st. The 8th place, @Asaoix, participated in round 763 and get 6th. And so on....

These newbies, I called, are fake newbies. Because they are not newbie level, they are far more than that. Some of the newbie users are even red level, they have low rating only because they are new users and only take a few contest, and the rating cannot accurately measure their level.

Besides, you will not get your performance rating in the contest, if you get rank 1, your new rating will not be rank 1 rating, you new rank will based on your previous rating and this contest performance. If you have 1400 rating, and your performance is 2600 in a contest, you will get probably one third of the difference, say 1800. But if you are 2600 level, 1800 can still not measure your real ability. In general, you need to take at least 4 contests to have your rating consistent with your ability.

Why I mention this ? I am not making complaints. It's a good thing, since codeforces has been expanding from time to time, more and more talented programmers are joining in codeforces platform. They have already achieved well in other platforms, and codeforces should welcome them. The only thing I care is the rating calculation.

In each contest, you get rating based on how many users you defeat, and how many users defeat you, and what their ratings are. If you defeat a user that have high rating, your rating will increase, and if you are defeated by a low rating user, your rating will drop. The detailed rating calculation are listed here

Therefore, if you are defeated by these fake newbies, the rating system will say: "Hey, you are so suck. You are defeated by these newbies, your rating will not be good." Which is not true. You cannot make them unrated, it's unfair to them. And here is my suggestion, like div3 does:

Make a pool of trusted users for all contests(not only div3). Every rated users who participate more than 3 or 4 contests will be marked as trusted users. Everyone's rating will only be determined by these trusted users, and every users within the rating range will be rated whether it is trusted or not.

Another reason that so many fake newbies is that they are the alternative account of some high level user. It is discouraged, but it is very difficult to discover. Since many users, they have multiple accounts, and only use one account in the contest. By expanding the "trusted users" idea, they will have no influence to the low level users.

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Comments Comments (19)
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3 years ago, # |
  Vote: I like it +9 Vote: I do not like it

Auto comment: topic has been updated by hxu10 (previous revision, new revision, compare).

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3 years ago, # |
  Vote: I like it +40 Vote: I do not like it

CF764 (Div3) has this rule:

To qualify as a trusted participant of the third division, you must:
take part in at least five rated rounds (and solve at least one problem in each of them)

I wonder why CF765 (Div2) doesn't.

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    3 years ago, # ^ |
      Vote: I like it +293 Vote: I do not like it

    Actually, I plan to introduce the trusted participants feature for Div2 rounds too.

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      3 years ago, # ^ |
        Vote: I like it +30 Vote: I do not like it

      Is it true that untrusted div3 participants don't have any effect on the rating changes of the other participants? Or are they only filtered out from the scoreboard and don't show up in the top 10, while still eating rating points of the others?

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      3 years ago, # ^ |
        Vote: I like it +3 Vote: I do not like it

      MikeMirzayanov Please introduce a feature to filter standings according to college. As a first year student we don't know much good coders in college and it will make us easy to find good competitive programmers from our college.

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        3 years ago, # ^ |
          Vote: I like it +3 Vote: I do not like it

        there is something like that keep hoping the menus in rating section you will find it

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      2 years ago, # ^ |
        Vote: I like it +11 Vote: I do not like it

      How is it going with the new feature?

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3 years ago, # |
  Vote: I like it +53 Vote: I do not like it

https://codeforces.me/blog/entry/77890

According to the rating system, they weren't defeated by a newbie, they were defeated by a 1400, 1600 or 1800 rated person(depending on which of those 5 newbies you're looking at).

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3 years ago, # |
← Rev. 3   Vote: I like it +4 Vote: I do not like it

These newbies are maybe someone has $$$2400+$$$ rating and this rounds are their second round. They are GMs!

But the feeling of a CM who be beaten by "newbies" may be not so great.

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3 years ago, # |
  Vote: I like it +62 Vote: I do not like it

In Chinese, "newbie" have the same pronunciation with "牛掰", which means the person is powerful.

Just kidding. :)

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3 years ago, # |
  Vote: I like it -10 Vote: I do not like it

Eason_Ak is EasonCf, he changed his username recently to something other. He has another account Eason_AC.

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3 years ago, # |
  Vote: I like it 0 Vote: I do not like it

https://codeforces.me/blog/entry/98903

This one, Newbies are the new conqueror...xD

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