This data set includes the binary 'berserking' choice of participants in the yearly bullet arena 2022 on the online chess platform https://lichess.org. 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.

## Usage

data(choice_berserk)

## Format

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

## Source

The data was obtained via the lichess API https://lichess.org/api with the tournament id 'RibHfoX6' on 2022-03-29.

## Details

To 'berserk' is a feature on the online chess platform https://lichess.org. 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.

## References

See https://lichess.org/tournament/help?system=arena for more information on the tournament format.