Time management refers to algorithms and heuristics to allocate time for searching a move under time control requirements in a game of chess. The player to move consumes his time, and if he exceeds his time limit, the game is lost on demand of the opponent player, or in automatic computer chess play by an arbiter instance.
Iterative deepening in conjunction with its predictable effective branching factor allows a flexible time management either to terminate the current iteration and to fall back on best move and PV of the previous iteration, or to decide about termination prior to start a new iteration or to search a next root-move.
Fast chess is usually played with an immediate sudden death time control, while others may have one or more regular time controls before the sudden death control applies there as well.
Sudden Death
Sudden death refers to a requirement that all the remaining moves, rather than a fixed number of moves, need to be played within the remaining time. Typically programs estimate the game will last further 25..40 moves, and divide the remaining time by this number.
Regular Time Controls
Regular time controls define a number of moves to be made in a fixed amount of time. We don't have to make estimations for how long the game will last. However, some time should be saved in order to have a buffer in case later moves warrant longer thinking times.
Time Control with Increment
To avoid time trouble where often blunders decide the game, chess champions, most notable Bobby Fischer and David Bronstein, proposed a delay or increment of time for each move made. It requires a special delay clock, which became handy with the development of digital chess clocks in the 70s and 80s [3] .
Time trouble is also an issue in computer chess, either due to operators in over the board chess, boosted by deviation of internal and external clock, or in transmitting move transfer latencies in automatic play, where it is quite common nowadays to play with increment per move.
Fischer Time
In 1988 Bobby Fischer proposed an unconditional increment per move, no matter whether the delay was exhausted or not. With Fischer time one may therefor increase the remaining time if one moves faster than the delay [4] .
Bronstein Time
Bronstein's time works similar, but never increases the remaining time. It was for instance used during the late Aegon Tournaments.
Enhancements
Human chess players often wonder about the inflexible time management of various programs. A basic time management scheme might be enhanced in several ways, considering dynamic, statistical as well as static features of the search, the best move and its PV.
Considerations
How often did the best move change during the (last N) previous iterations?
The score function over iterations and best moves, increase or decrease and/or oscillation, score amplitude, etc.
The ratio of the size of the subtree under the best move versus the size of the whole search tree
Only one obvious way to recapture in an otherwise quiet position
Premature Termination
Only one legal move
Prior a start of a new iteration, the relation of elapsed and allocated time (f.i. > 50%) [5]
Extra Time
Fail low situations, a severe drop of the score may cause programs to allocate "panic time" to hopefully solve the critical situation
During the first moves out of the opening book programs often allocate more time
For instance, Robert Hyatt gave following formula from Cray Blitz in Using Time Wisely[6]
New and therefor likely not singular best moves, but statically "suspect", like weakening the pawn structure or a sacrifice favors to allocate extra time and to start a further iteration, even if the score is fine.
Robert Hyatt, Albert Gower, Harry Nelson (1985). Using Time Wisely, revisited (extended abstract). Proceedings of the 1985 ACM annual conference on The range of computing: mid-80's perspective, p. 271, Denver, Colorado. ISBN 0-89791-170-9.
Shaul Markovitch, Yaron Sella (1993). Learning of Resource Allocation Strategies for Game Playing, The proceedings of the 13th International Joint Conference on Artificial Intelligence, Chambery, France. pdf
Iterative deepening in conjunction with its predictable effective branching factor allows a flexible time management either to terminate the current iteration and to fall back on best move and PV of the previous iteration, or to decide about termination prior to start a new iteration or to search a next root-move.
Table of Contents
Time Controls
Fast chess is usually played with an immediate sudden death time control, while others may have one or more regular time controls before the sudden death control applies there as well.Sudden Death
Sudden death refers to a requirement that all the remaining moves, rather than a fixed number of moves, need to be played within the remaining time. Typically programs estimate the game will last further 25..40 moves, and divide the remaining time by this number.Regular Time Controls
Regular time controls define a number of moves to be made in a fixed amount of time. We don't have to make estimations for how long the game will last. However, some time should be saved in order to have a buffer in case later moves warrant longer thinking times.Time Control with Increment
To avoid time trouble where often blunders decide the game, chess champions, most notable Bobby Fischer and David Bronstein, proposed a delay or increment of time for each move made. It requires a special delay clock, which became handy with the development of digital chess clocks in the 70s and 80s [3] .Time trouble is also an issue in computer chess, either due to operators in over the board chess, boosted by deviation of internal and external clock, or in transmitting move transfer latencies in automatic play, where it is quite common nowadays to play with increment per move.
Fischer Time
In 1988 Bobby Fischer proposed an unconditional increment per move, no matter whether the delay was exhausted or not. With Fischer time one may therefor increase the remaining time if one moves faster than the delay [4] .Bronstein Time
Bronstein's time works similar, but never increases the remaining time. It was for instance used during the late Aegon Tournaments.Enhancements
Human chess players often wonder about the inflexible time management of various programs. A basic time management scheme might be enhanced in several ways, considering dynamic, statistical as well as static features of the search, the best move and its PV.Considerations
Premature Termination
Extra Time
For instance, Robert Hyatt gave following formula from Cray Blitz in Using Time Wisely [6]
inspired by following graph of human timing from several grandmaster tournament games
grandmaster thinking time (minutes) ^ ## 15 + # # | # # | # # | # # | # # 10 + # # | # # | # # | # # | # # 5 + # # | # ### | ## ####### | ## ######## |######## ############ 0 +---------+---------+---------+---------+---------+---------> 0 10 20 30 40 50 Moves playedLosing on Time
See also
Publications
Forum Posts
1993 ...
2000 ...
2005 ...
2010 ...
- As though they were pondering by Gabor Szots, CCC, July 23, 2010 » Pondering
- Move on Hash Hit by kingliveson, OpenChess Forum, August 18, 2010 » Pondering
- New Time Controls for WB by Matthias Gemuh, CCC, August 30, 2010 » Chess Engine Communication Protocol, WinBoard, ChessGUI
2012- Sudden death time controls by Larry Kaufman, CCC, May 10, 2012
- Winboard protocol and fractional increments by Jon Dart, CCC, September 25, 2012 » Chess Engine Communication Protocol, WinBoard
- Adjustable search pruning depending on time control by Jerry Donald, CCC, December 20, 2012 » Pruning, Late Move Reductions
2013- "panic time" and "easy moves" by Robert Hyatt, CCC, February 16, 2013
- Yet another time allocation heuristic by Steven Edwards, CCC, February 17, 2013
- easy-hard moves (again) by Robert Hyatt, CCC, March 08, 2013
- Easy easy move by Harm Geert Muller, CCC, August 02, 2013
- out-of-time: what to do? by Folkert van Heusden, CCC, August 09, 2013
- Losing on time by Gregory Strong, CCC, December 31, 2013
20142015 ...
- Elo gain and optimal time management by Kai Laskos, CCC, January 11, 2015
- What's the fastest time control you can effectively test at? by Jordan Bray, CCC, May 30, 2015
2016- Photographing Chess Clock by Harm Geert Muller, CCC, October 10, 2016
- Doubling of time control by Andreas Strangmüller, CCC, October 21, 2016 » Doubling TC, Diminishing Returns, Playing Strength, Komodo
- New idea for "easy move detection" by Rasmus Althoff, CCC, November 05, 2016 » CT800
- Stockfish 8 - Double time control vs. 2 threads by Andreas Strangmüller, CCC, November 15, 2016 » Doubling TC, Diminishing Returns, Playing Strength, Stockfish
- On time management by Rasmus Althoff, CCC, December 24, 2016
2017- Time managment ? by Mahmoud Uthman, CCC, March 07, 2017
- Time management ideas by lucasart, OpenChess Forum, April 03, 2017
- Invariance with time control of rating schemes by Kai Laskos, CCC, July 22, 2017 [7]
- Time Managment translating to SMP by Andrew Grant, CCC, December 23, 2017 » Parallel Search
2018External Links
Hiromi Uehara, Martin Valihora, Tony Grey, David Fiuczynski
References
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