hxu10's blog

By hxu10, history, 23 months ago, In English

I have participated in four div 1 only contests, and every time ends up in very big negative data. First time, I thought it is just coincidence, but 4 times, every time I lost big, then in the contest 796 , I do an experiment.

The score distribution: div1: 500, 750, 1500, 1500, 2000, 3000 div2: 500, 750, 1250, 1500, 2000, 3000

ABC in div1 corresponds to DEF in div2. According to each problems accepted users, the difficulty ranking of each problem is div2A <= div2B << div1A < div2C < div1B << div1C << div1D..... More difficult a problem is, more time a user expect to spend.

Assume a user takes part in div 2 contest and solve 5 problems, and finish each problems in time 0:05, 0:10, 0:40, 1:00, 1:50, with no wrong submissions. His score, according to the rule should be 490+720+1050+1140+1120 = 4520, he will rank 93 in this contest, and his performance rating is 2147 according to the rating predictor.

Then, this user takes part in div 1 contest, since div1C is very hard, and he is not able to solve it. He will solve only two problems, with time 0:20, 1:10 (each subtract 40 minutes), and his score will be 460+540=1000, and his ranking is over 550, with performance rating less than 1900.

That means, if his current rating is 1899 and participate div2, he will gain big rating (about +60), however, if his rating is 1900 and participates div 1, he will lose rating and go back to expert.

I would like to ask if you all have the same feeling, that is, it is harder to gain rating in div1 only contest?

  • Vote: I like it
  • +115
  • Vote: I do not like it

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23 months ago, # |
  Vote: I like it +12 Vote: I do not like it

I personally don't like speedforces rounds either.

However, I think it's fair that if the lowest-ranked participant places last he should lose some rating.

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23 months ago, # |
  Vote: I like it +23 Vote: I do not like it

As a person, whose rating is almost always around division border:
Of course it's harder to gain rating in div1 only: you should perform better, than anybody who is stronger than you. But on the other hand it's harder to lose rating in div1 only contest: if you solve 0, you lose at most 100, but failing in div2 only (and combined) means at least -100.
I always prefer combined/d2only rounds as 1900-2100 participant. For example in today's round I'd have 2204 perfomance in div1, but in div2 I have 2342. Though to be honest 2204 is more likely to be my actual rating rather than 2342

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23 months ago, # |
  Vote: I like it +33 Vote: I do not like it

I agree with this feeling, and I can imagine it causing a cycle for users who are currently in the cm/master level where they'll each time jump to master with a good div.2 and then slowly decay back to CM. I think the main reason for that (at least for me) would be that speed matters a lot more in div.2 if you're in that level, I for example feel that speed gives me a slight advantage in div.2 where a lot of people solve about the same problems, but I get stuck on the medium/easy problems in div.1, so it doesn't help me.

At the end of the day div.1 should be harder, because it needs to control a huge range of strong users (CM to LGM), and the point is to make everyone fall eventually into their real rating, like you said someone can gain an advantage with a good div.2 that a master won't have, but I don't think it's a big problem since it's always temporary.

P.S take everything I say with a grain of salt, I haven't participated in enough contests to be sure about anything really.

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22 months ago, # |
  Vote: I like it 0 Vote: I do not like it

Personally, I used to be really bad at Div 1s and Div 1 + 2s (you can check my contest history) compared to my Div 2 performance. I think the main issue is that one should not expect to solve many problems in the problemset, and perhaps require different mindsets going into it. Knowing that Div1s for CMs and M/IM are going to be speedforces in many cases, I guess the best way to adopt this mindset is to just do more virtual div1s.

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22 months ago, # |
  Vote: I like it 0 Vote: I do not like it

It's a bit hard to compare when you do the analysis like how you've done it, because you have to consider the fact that in div1 you have a chance to do some of the harder problems. If you can solve div1b consistently then you will be able to either solve div1c or div1d sometimes, which would pull your rating up.

It may be easier to gain rating in div1 if you are a competitive div1 contestant, and easier to gain rating in div2 if you are a weaker div1 contestant with very low odds to solve difficult problems.