Some Statistics About CF Rating Changes

Revision en4, by adrien1018, 2018-03-25 16:37:47

Overview

There are 1263879 rating changes in 745 rated contests (by 2018/03/15, including those mentioned in the "Something Weird" section). The overall average of deltas is -6.30274.

Rating Changes Distribution

(Well, it looks like a boa constrictor eating an elephant...)

Top 20 Events: Positive Rating Change

# Who Δ Rating Contest
1 Mhammad1 +803 -22 → 781 Codeforces Round 418 (Div. 2)
2 white_1 +756 522 → 1278 Educational Codeforces Round 35 (Rated for Div. 2)
3 worse +644 230 → 874 Codeforces Round 372 (Div. 2)
4 .o. +548 872 → 1420 8VC Venture Cup 2016 - Final Round (Div. 2 Edition)
5 rakhashov.maksat +535 1088 → 1623 Codeforces Round 332 (Div. 2)
6 NelsonMondialu +526 310 → 836 Educational Codeforces Round 35 (Rated for Div. 2)
7 my_new_handle +519 878 → 1397 Codeforces Round 451 (Div. 2)
8 Spongebob_kz +474 238 → 712 Codeforces Round 411 (Div. 2)
9 CommonAnts +448 1376 → 1824 Codeforces Round 404 (Div. 2)
10 angoor +446 889 → 1335 Codeforces Round 368 (Div. 2)
11 mrloser +444 1355 → 1799 Good Bye 2014
12 I_hate_Shadow_Light +440 1315 → 1755 Codeforces Round 461 (Div. 2)
12 Helli.code +440 1110 → 1550 Codeforces Round 447 (Div. 2)
14 koamy +439 1163 → 1602 Codeforces Round 355 (Div. 2)
15 FUUUUUUUUUUUUUUUUUUUCK +428 798 → 1226 Codeforces Round 390 (Div. 2)
16 no_name_weak_vegetable +425 1500 → 1925 Codeforces Round 270
17 TERESO +423 1446 → 1869 Codeforces Round 417 (Div. 2)
18 osman_n +420 508 → 928 Codeforces Round 417 (Div. 2)
19 SPFA_THE_BEST_ALGORITHM +418 1500 → 1918 Manthan, Codefest 17
20 Luqman +417 1523 → 1940 Good Bye 2014
20 YouAllHaveMeizi +417 1500 → 1917 Good Bye 2014

Top 20 Events: Negative Rating Change

# Who Δ Rating Contest
1 yosupo -336 2709 → 2373 Divide by Zero 2017 and Codeforces Round 399 (Div. 1 + Div. 2, combined)
2 jcvb -296 2999 → 2703 Canada Cup 2016
3 tourist -290 3496 → 3206 Codeforces Round 470 (rated, Div. 1, based on VK Cup 2018 Round 1)
4 snuke -284 2695 → 2411 Manthan, Codefest 17
5 yosupo -263 3113 → 2850 Codeforces Round 431 (Div. 1)
6 King_George -255 2263 → 2008 Codecraft-18 and Codeforces Round 458 (Div. 1 + Div. 2, combined)
7 PavelKunyavskiy -253 3097 → 2844 8VC Venture Cup 2017 - Elimination Round
8 AllCatsAreBeautiful -247 2237 → 1990 Codecraft-17 and Codeforces Round 391 (Div. 1 + Div. 2, combined)
9 V--o_o--V -240 3271 → 3031 ICM Technex 2017 and Codeforces Round 400 (Div. 1 + Div. 2, combined)
10 Reyna -239 2490 → 2251 Codeforces Round 397 by Kaspersky Lab and Barcelona Bootcamp (Div. 1 + Div. 2 combined)
10 I_love_Tanya_Romanova -239 2965 → 2726 Manthan, Codefest 17
12 Temirulan -238 2445 → 2207 8VC Venture Cup 2017 - Elimination Round
13 fukirk -235 1497 → 1262 Codeforces Beta Round 60
14 vagnard -233 2294 → 2061 CROC 2016 - Elimination Round (Rated Unofficial Edition)
14 .I. -233 2199 → 1966 Playrix Codescapes Cup (Codeforces Round 413, rated, Div. 1 + Div. 2)
16 enot110 -232 2880 → 2648 Codeforces Round 349 (Div. 1)
17 loser -231 1482 → 1251 Codeforces Beta Round 60
17 King_George -231 2449 → 2218 Codeforces Round 397 by Kaspersky Lab and Barcelona Bootcamp (Div. 1 + Div. 2 combined)
19 Pepe.Chess -230 2367 → 2137 Tinkoff Challenge - Final Round (Codeforces Round 414, rated, Div. 1 + Div. 2)
20 subscriber -225 2786 → 2561 Tinkoff Challenge - Elimination Round
20 ainta -225 3048 → 2823 Codeforces Round 424 (Div. 1, rated, based on VK Cup Finals)

Top 10 Users: Consecutive Positive Rating Changes

# Who # consecutive
1 tourist 21
2 RAD 14
2 xyz111 14
4 KK_ndv 13
4 guoyu1098 13
6 Matei.Chirita 12
6 Rafaelcs 12
6 vepifanov 12
6 green_frog 12
6 harshit_ag456 12

Top 10 Users: Consecutive Negative Rating Changes

# Who # consecutive
1 worse 31
2 Mhammad1 25
3 ahmed_25 22
4 newbie314159 21
5 NelsonMondialu 19
6 .o. 18
7 THton 17
7 Adai_is 17
9 MisterMax 16
10 ashutosh08 15
10 erudite 15
10 cyclone_chaple 15
10 Yoyo2014 15
10 asha_42 15
10 Yerassyl 15

Top 10 Contests: Positive Averaged Rating Change

# Contest Avg. Δ # participants
1 Manthan 2011 34.309 745
2 Codeforces Beta Round 88 21.053 1103
3 Codeforces Beta Round 81 20.353 1034
4 Codeforces Beta Round 87 (Div. 1 Only) 16.067 416
5 Codeforces Beta Round 91 (Div. 1 Only) 15.448 420
6 Codeforces Beta Round 92 (Div. 1 Only) 15.140 365
7 Codeforces Beta Round 85 (Div. 1 Only) 14.957 398
8 Codeforces Beta Round 83 (Div. 1 Only) 14.909 351
9 Codeforces Beta Round 86 (Div. 1 Only) 14.389 355
10 School Regional Team Contest, Saratov, 2011 14.331 580

Top 10 Contests: Negative Averaged Rating Change

# Contest Avg. Δ # participants
1 VK Cup 2012 Round 3 (Unofficial Div. 2 Edition) -31.142 643
2 VK Cup 2012 Round 2 (Unofficial Div. 2 Edition) -28.747 707
3 Croc Champ 2012 - Round 2 (Unofficial Div. 2 Edition) -27.681 627
4 Codeforces Round 112 (Div. 2) -27.462 1518
5 Codeforces Round 113 (Div. 2) -26.989 1443
6 Codeforces Round 324 (Div. 2) -20.562 4333
7 Croc Champ 2012 - Round 2 -20.151 338
8 Codeforces Round 114 (Div. 2) -19.963 1395
9 Codeforces Round 326 (Div. 2) -18.719 3838
10 Codeforces Round 323 (Div. 2) -18.305 4728

Rating: Sum, Average, Standard Deviation and Skewness

A user is included in the sum only after their first participation in a contest.
Note that we can observe changes of rating system (November 2011 and October 2015) on the graph.

(I wondered if there were changes in March 2012, since the top 5 contests with most negative average delta are all in March or April 2012. However, I didn't find any related posts.)

Something Weird

  1. In Codeforces Round #FF (Div. 2), kasim appeared in both #1095 and #1986.
  2. In Codeforces Round 270, yuki2006 appeared in both #2876 and #3520; a00920 appeared in both #1097 and #3602.
  3. In Codeforces Round 338 (Div. 2), bohuss appeared in both #256 and #3477; InnocentFool appeared in both #555 and #3477; elgris appeared in both #884 and #3477; Altitude appeared in both #2439 and #3477; mohamedazab appeared in both #2831 and #3477. (Such a buggy round?)
  4. In MemSQL Start[c]UP 2.0 - Round 2, FreezingCool had a rating change of +5, but it wasn't displayed on the user page. (Can somebody explain why max rating is smaller than contest rating?)
  5. In Технокубок 2018 - Отборочный Раунд 4, Roma_Pussy had a rating change of -83. However, it seems that the rating is not actually changed. After that, his ratings displayed on "contest rating" and "rating change" in contest pages was 83 higher than those on the user history graph.
  6. In contest pages, ratings less than 100 are displayed as 100. 5 users have been affected: worse, MisterMax, newbie314159, errorerror, and Mhammad1.
Tags rating, history, statistics

History

 
 
 
 
Revisions
 
 
  Rev. Lang. By When Δ Comment
en7 English adrien1018 2018-07-16 11:58:22 20
en6 English adrien1018 2018-07-16 11:44:04 5986
en5 English adrien1018 2018-03-25 16:38:47 2 Tiny change: '="90%"/>\n(Well, i' -> '="90%"/>\n\n(Well, i' (published)
en4 English adrien1018 2018-03-25 16:37:47 63 (saved to drafts)
en3 English adrien1018 2018-03-16 13:51:31 193
en2 English adrien1018 2018-03-16 13:26:33 233
en1 English adrien1018 2018-03-16 06:10:38 18827 Initial revision (published)