RetroC temporal classification challenge for Vietnamese

Guess the publication year of a Vietnamese text. The metric is root mean square error. [ver. 1.0.0]

# submitter when ver. description dev-0 RMSE test-A RMSE
4 kubapok 2020-01-09 17:28 1.0.0 tfidf lr linear-regression tf-idf 53.34666712490475 68.53470916704357
1 p/tlen 2016-03-13 09:04 1.0.0 Vowpal Wabbit -nn 6 on up to 4-grams (for characters) 6.334965346282399 7.231304342176452
2 p/tlen 2016-03-13 08:51 1.0.0 by year references 13.964113179810743 14.440447392767396
3 p/tlen 2016-03-13 08:43 1.0.0 null model (always return 1990.0) 18.76801034852546 21.05417732936992