Very different positive delta for rank 4 and rank 5 in july Lunchtime

I want to understand how rank 4 of July lunchtime div2, got +314 which got him to 2251 from 1937. But the rank 5 got only +42 even though his initial rating was lesser.
Both profile links:
You can check out the rank list for even more bizarre rating updates.


maybe because of this system going live : Elo-MMR ratings go live on CodeChef! - Codeforces

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The rating system changed today. Sadly they decided to make the change as hidden as possible. Everyone had their past contests recalculated and currently everyone has 2 different ratings. The public one (Code Chef rating) and an hidden one (the new Elo-MMR rating).

Since today, only your Elo-MMR rating will update. And since this is a different rating, it is very likely it was different than your old rating. Your public rating will converge to the Elo-MMR rating within a few contests.

In the near future, everyone’s old rating will be set to the Elo-MMR rating. Why it was not done already I don’t know.


elaborate about what exactly? I don’t know the details either.

I guess ratings are calculated to first 4 users

It is not hidden, if you do want to look for it.


Thanks for replying, so as I understand, the new rating system benefitted rank 4 because it was a new account ?? right?
So its just easier to create a new account and then push for 5 star instead of grinding it on an old account?


It all depends but this can happen, yes.

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