Jarekczek's blog

Users colors stats 2010-2021
By Jarekczek, history, 3 years ago, In English

I was asked to prepare more stats similar to these charts.

So I present numbers of active users by colors, both absolute and relative, for lifetime of Codeforces.

Absolute users count

The dotted line indicates total number of active users. Absolute users count

Relative users count

Relative users count

Relative cumulative users count

Relative cumulative users count

Assumptions

Active users means users who:

  • participated in a rated contest in 6 months preceding given date
  • participated in at least 1 rated contest

Measurements are taken every 3 months.

Definitions of colors are from today, for example green is 1200-1399.

Tools

Tooling is contained in this repo. It consists of:

  • java application downloading and caching contests' results, calculating data rows
  • python script generating the plots

Repo also contains the data produced by java application.

Evening update

Since system penalty indeed affects rating of new users, it would be reasonable to make another probe. This is absolute count as before, but now 6 contests are required to consider a user active.

  • Vote: I like it
  • +75
  • Vote: I do not like it

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3 years ago, # |
  Vote: I like it +8 Vote: I do not like it

Number of CP'ers almost tripled since lockdown.Just wow.

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

For those wondering what the spike in newbies is caused by, it seems likely that it's from the change starting new users at 0 rating rather than 1400, rather than by lockdowns.

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    3 years ago, # ^ |
      Vote: I like it +5 Vote: I do not like it

    Good point. I could remove the penalty score from new users rating, but it would require some work. It's easier to simply require 6 contests for a user to appear in the chart. Added this as an update.

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