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Why the problem difficulty inaccurate to units? Such as 1500 not 1548

Revision en6, by ZhouShang2003, 2020-07-14 05:39:21

As we all know, a coder with A rating has a 1/(1+10^((B-A)/400)) probability of accepting a B difficulty problem.

At present, the following situations may occur: Two equally difficulty problems have a difference of 14.3% in acceptance rate; Two problems with a difficulty difference of 100 have the same acceptance rate. Accurating difficulty to units can reduce errors to 0.1%.

Codeforces Beta Round #23 has only 765 participants, Codeforces Global Round 9 has 21150 participants, so we can definitely make difficulties more accurate by using participants that have increased by more than 25 times.

By the way, would not it be better to have the same accuracy of rating between the problems and coders?


  Rev. Lang. By When Δ Comment
en6 English ZhouShang2003 2020-07-14 05:39:21 22 Tiny change: 'iculty to one places can redu' -> 'iculty to units can redu'
en5 English ZhouShang2003 2020-07-12 05:46:12 4 Tiny change: ' problem. At present' -> ' problem. \n\nAt present'
en4 English ZhouShang2003 2020-07-12 05:42:38 6 Tiny change: ' problems with a differe' -> ' problems have a differe'
en3 English ZhouShang2003 2020-07-12 05:39:41 2 Tiny change: 'ay occur: two equally' -> 'ay occur: Two equally'
en2 English ZhouShang2003 2020-07-12 05:38:21 1 Tiny change: 'ance rate.Accurating' -> 'ance rate. Accurating'
en1 English ZhouShang2003 2020-07-12 05:34:44 787 Initial revision (published)