TCEC DFRC rules

TCEC Double Fischer Random Chess - Rules & Information

Rules

1. Event

a. For all TCEC Events, engines will be invited by the organizers.

b. The TCEC DFRC is a progressive leagues knockout format played in TCEC, including all invited qualifying participants.

c. The qualifying engines consist of the top engines able to play Double Fischer Random Chess natively under Linux, dropping those that are out of apparent development. The Tournament Direction at its discretion may invite additional engines to complete an even number.

d. The engines will be seeded taking into account earlier results and standings in recent TCEC Events, to the discretion of the organizers.

e. If the winner of the last completed TCEC DFRC participates, it will be seeded number 1.

2. TCEC DFRC Event format

a. The participating engines are seeded into 3 Leagues, called League 3, 2, and 1.

b. In League 3, 10 engines will play a 1x double round robin at TC 30'+3" with a DFRC opening set without moves; the top 2 engines qualify for and promote to League 2.

c. In League 2, 10 engines will play a 1x double round robin at TC 30'+3" with a DFRC opening set without moves; the top 2 engines qualify for and promote to League 1.

d. In League 1, 8 engines will play a 2x double round robin at TC 30'+3" with a DFRC opening set without moves; the top 2 engines qualify for and promote to the DFRC Final.

e. The top 2 engines of the Final League advance to the Final, in which they will play 50 games (25DRR) at TC 30'+3" with a DFRC opening set without moves.

f. In case the Final ends in a tie on points after 50 games, pairs of games at the same time control will be played until one engine wins such a pair.

3. Tiebreaks

If necessary, tiebreaks shall be used to determine advancement in the Leagues, based on the final standings of a League. For all Events except the Final, the following criteria will be used, in the order as presented below:

1. In case of engines being tied, then the direct encounter(s) between the tied engines decides first.

2. The Sonneborn-Berger is the second criterion.

3. r-mobility tiebreak is the third criterion.

4. The fourth criterion is the greatest number of wins.

5. In the unlikely event they are even then still tied, then the tournament organizers will decide which engine gets the promotion or relegation.

4. Openings books

a. All matchups will be played from a randomly generated DFRC start position.

5. Time control

a. Time control will be 30 mins + 3 secs increment per move for all games in a match, including the tiebreakers.

b. If an engine loses on time, that results in a loss and will be registered as such. The game will not be replayed.

6. Game ending

a. A game can be drawn by the normal 3-fold repetition rule or the 50-move rule.

b. The improved TCEC draw rule applies when a game has reached a position with 6 or fewer pieces (including kings, excluding pawns) and where the engine evaluation of the move leading to the position was in [-0.25,0.25]. The game is adjudicated as a draw if the draw rule applies on 8 consecutive plies. The counter resets to 0 in the follwing cases: (1) if the draw rule ceases to apply because of a pawn promotion causing a 7th piece to appear, or (2) an evaluation outside of the [-0.25,0.25] range or the absence of an evaluation by an engine appears. There is no reset for capture or pawn move, and no stipulated minimum move number for adjudication.

c. Cutechess-cli will adjudicate positions with 6 pieces automatically with Syzygy tablebases.

d. If an engine loses on time, the result will not be changed nor the game replayed.

7. Crashes

a. Engine crashes are counted as losses.

b. In case of a server disconnect, or time loss due to lag, or other interruptions not caused by the engines there are five possible scenarios:

i. If the web server crashes, the game continues unaffected, and broadcasting will be resumed as soon as possible;

ii. If the evaluation of both engines is equal to or more than ABS(10) at the moment of game server interruption, the game is scored as a win;

iii. If the evaluation of both engines is equal to or less than ABS(0.15) at the moment of game server interruption, and both engines have completed 35 moves, the game is scored as a draw;

iv. If a game interrupts with 7 pieces on the board, position on the board at the instant of game server interruption will be adjudicated according to 7-man EGTB;

v. In all other cases the game is restarted from the position that the two engines reached before the disconnect, with time compensation to fill up the cache.

c. Whether a game is immediately restarted or played rather at the end of the round will be decided by the responsible TCEC staff.

8. Engine Updates

a. Under no circumstances are updates and fixes to engines allowed once the FRC tournament has started.

Guidelines

See the FIDE rules Section Guidelines II. Chess960 Rules (the nomenclature of FIDE, in contrast to Wikipedia, fails to acknowledge this chess variant's inventor Bobby Fischer, naming it anonymously "Chess960" after the number of possible positions).

Further information

See also

• TCEC Season Further information