New Rating Divisions (Div1/Div2) on Codechef

Hey Guys! :slight_smile:

As we all had been suggesting to codechef since past many months to have a separate rating divisions, i.e. separate Div1/Div2 contests, the devs have been working hard since past few months to implement it. Lo and Behold! As evident from yesterday’s sneak peek given on Codechef’s Facebook page, the feature is live, starting from current long challenge. Thats Chef’s way of surprising us on his 9th Birthday :slight_smile:

What is it primarily?

Speaking of the feature in short, it is as follows-
The users, and the contests, will be divided into 2 divisions. Users with rating <1800 will be allotted Div2, while users with rating \ge1800 will be alloted Div1. Each of the contests, like, long, cookoff and lunchtime will now have 2 parallel contests running- one for each division. Div2 will have easier problems than Div1.

Why this change?

  1. It was user requested and Chef listens to all the suggestions he gets :stuck_out_tongue:
  2. A user will be rated on basis of participants in his own division. This ensures that ratings reflect your skill closely.
  3. User will get problems with difficulty suited to his taste. No more complaints to excessive spice or too bland and boring :stuck_out_tongue: :wink:
  4. This system can potentially allow codechef to have more external rated contests by making them rated for Div2

What exactly changes?

1. Contest

  • Each contest has been divided into 2 divisions. Div1 and Div2.
  • A user can participate in contest of only his division. Example- A Div2 user trying to participate in Div1 contest is not allowed. Same for vice-versa.
  • In case of only Div2 rated contests, if unofficial participation is allowed, Div1 users may participate- this depends solely on the discretion of @admin /contest organizer.
  • Although Div1 and Div2 are two different contests with separate ranklist, they do share some common problems. The contests have some unique problems, and some problems shared with other division. Example, Div2 this long has, first 3 problem of as unique, while rest are shared with Div1. Similarly Div1 has last 3 problems as unique. (First 3 and last 3 w.r.t. difficulty scale)
  • Each Division will have 8 problems, out of which, one will be challenge or tie-breaker problem. (*Number of problems can change in future.)

2. Rating Calculation-

  • Rating of each user is calculated based on participants of his division. Submissions in Div1 will not affect rating of Div2 and vice-versa, EXCEPT in case of plagiarism.
  • This also means that the contest leader board will only cater to, and show rankings of participants of its own division.
  • However, MOSS and plagiarism checking will be applied to both contests as a whole(just like it happened till now.). Meaning, if for a common problem, a Div1 guy’s code matches with Div2 guys code , both of them will be penalized.

3. Prizes-

  • The prizes for Div1 remain same as normal contest before. Prizes for Div2 are changed. You can refer to here for exact changes.
  • Any use of unfair means will lead to penalty, whether in form of laddus, cancellation/forfeiting of prizes, and/or permanent suspension of account.

Any questions, queries and suggestions on above are welcome. We will try to edit in more information to suit your queries as and when applicable. :slight_smile:

With Regards
@vijju123

13 Likes

kya kia @admin ne … ab red coders ke saath compete karne me maja nahi aayega
huh !! not good

2 Likes

Well this is a nice change.Also consider this -

Another important and simple feature will be button for copying test cases , just like the one introduced on codeforces , it really helps!!

8 Likes

Stupid question - if rating increases, one gets to Div 1 right ? ( After Rating Increment ) ( For next month )

1 Like

This can be absurd question, but isn’t 1800 very low border for Div.1? I just saw Div.1 long challenge problems, they are expectable hard for users who have 1800-1900 rating, because ~1800 here is like specialist in Codeforces and you just can see the difference. Do you have any thoughts about changing that cut-off?

12 Likes

This is a great move by codechef, it will make the community much stronger than ever.But I think there should be some common contests for both DIV1 and DIV2.The people whose rating is in 1800-1900 should get a chance to participate in DIV2 contests too.This will not affect the motivation in case the rating drop.I hope things to improve in coming months.

Thanks Chef,

P.S. Happy Birthday :smiley:

2 Likes

How many problems will there be in Cook-offs and Lunchtimes in each division?

Also, I think 1800 rating is a bit low for Div.1. Maybe 1900 or 2000 will be better?

Anyway, thanks CodeChef for this great feature and happy birthday to Chef :slight_smile:

1 Like

Just suggestion…@vijju123, @admin, Codechef can have virtual contest system. Ofcourse it won’t affect rating of user but can give chance to solve the problems under contest environment for those who missed the contest.

2 Likes

What will happen to laddus? Will country wise participation be counted according to their division or globally? @vijju123

Judging ratings should involve a lot more manual labor by the staff at CodeChef !

I personally think that the border rating of 1800 b/w Div1 and Div2 is a nice Idea as it will pamper and push the contestants with rating just above 1800 to contest with good programmers which will help them refine their skills. There is no point in participating in a contest in which you can easily solve all questions of that division…

1 Like

I submitted a solution of div 2 question no 3. According to the rule it should not show my ranking as I belong to div 1, but it is showing rank 974 and score 0. Why is it so and will it affect my overall rating ? @vijju123

1 Like

Here is my one suggestion.We can have a system of adding friends in codechef, in the same way as in codeforces.This really helps as you get to learn the important optimization version of different codes of same problem from high rated coders.

This has helped me a lot previously, and I think it will be great help for newbies too.

@vijju123 , @admin, I think it will be a positive move for community!

hello!
I think it will be very fun if the leader adds the user ranking by continent.
And also the ranking of countries by continent and in the world

This is a very good step because it motivates users with lower rating. Earlier I used to solve upto two problems but now I solved 6 problem and even attempted the 7th (got 5 points).

What if some school student in div1 purposely decreases his ratings to become div2 and win?

Div 2 prizes are reduced to one-third for this reason. If we see such instances, adjustments will be done to decrease prize further/kill that motivation of malpractice. Thats why I would urge the community to do fair play- malpractices will likely just reduce the prize.

1 Like

No one will do that. The prizes in div2 are like 50 laddus.

@mathecodician - We cannot assume that no one will do that. Some people feel they are too smart.

1 Like

A small edit: “>=1800” will be div1 whereas it is currently “<=1800”