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This data set includes the binary 'berserking' choice of participants in the yearly bullet arena 2022 on the online chess platform Berserking is a choice each player has at the beginning of each game: When a player clicks the 'Berserk button', they lose half of their clock time, but the win is worth one extra tournament point.




A data.frame containing berserking choices of 6174 chess players in 126902 online bullet (1+0) games. It consists of the following columns:

  • player_id, unique lichess username of the chess player

  • game_id, unique lichess identification of the game

  • berserk, 1 if the player berserked and 0 if not,

  • white, 1 if the player had the white pieces and 0 if not

  • rating, the player's lichess bullet rating at the start of the game

  • rating_diff, the rating difference to the opponent

  • lost, 1 if the player lost the game (and hence lost the streak) and 0 if not

  • min_rem, the number of minutes left in the tournament

  • streak, 1 if the player is on a streak (see the details) and 0 if not


The data was obtained via the lichess API with the tournament id 'RibHfoX6' on 2022-03-29.


To 'berserk' is a feature on the online chess platform Before the game starts, each player can click a button, after which they lose half of their clock time, but the win is worth one extra tournament point.

The considered tournament had the following characteristics:

  • The tournament started at 2022-01-10 17:00:25 and lasted 240 minutes.

  • The time control was 1 minute per player per game (bullet format).

  • The players are automatically and immediately paired again after a game has finished, which is the so-called 'arena tournament' modus.

  • The players can pause their participation at any time.

  • A win has a base score of 2 points, a draw 1 point, and a loss is worth no points.

  • If a player wins two games consecutively, they will start a double point streak, which means the following games will continue to be worth double points until they fail to win a game.


See for more information on the tournament format.