The Root of the Search Tree is the initial position of the search. Many programmers dedicate a separate function for doing a root search, since using a different move ordering scheme may be beneficial. Also root search must return not only the value, but also the move which will be played. This in turn may require special care in case of a fail-low when using aspiration window. This is typically where the time management decisions are beneficial.
See also
- Conspiracy Numbers
- Fail-Low
- Iterative Deepening
- Move Ordering - Root Node Considerations
- Multi-PV
- Oracle
- Piece-Square Tables - Pre-processing
- Scoring Root Moves by Ronald de Man
- Time Management
Forum Posts
1997 ...
- computer chess "oracle" ideas... by Robert Hyatt, rgcc, April 1, 1997
Re: computer chess "oracle" ideas... by Ronald de Man, rgcc, April 3, 1997
Re: computer chess "oracle" ideas... by Ronald de Man, rgcc, April 7, 1997
- Failing low at the root by Guido Schimmels, CCC, August 03, 1998
- Question: Fail High then Low at Root by William Bryant, CCC, December 28, 1999 » Fail-High, Fail-Low, Search Instability
2000 ...
- Can we use hash table at root? by Tim, CCC, January 31, 2000 » Transposition Table
- Question: Fail low at root and time management by William Bryant, CCC, February 08, 2000 » Fail-Low, Time Management
- Root move and incomplete iteration by Frank Phillips, CCC, December 11, 2000
Re: Root move and incomplete iteration by Robert Hyatt, CCC, December 11, 2000
- What means lazy/plain alpha bounding? by Severi Salminen, CCC, February 06, 2001 » Fail-High
2005 ...
- Even more search questions by Sven Schüle, Winboard Forum, July 17, 2007 » Iterative Deepening
2010 ...
- Root node search by Onno Garms, CCC, March 13, 2011 » Onno
- Root node search in Stockfish by Onno Garms, CCC, June 12, 2011 » Stockfish
- A few general questions... by Bill Henry, CCC, January 29, 2012 » Exact Score, Aspiration Windows
- Pruning in PV nodes by Sergei S. Markoff, CCC, January 14, 2014 » Reductions, Node Types
- Solving a fail low situation at the root by Alberto Sanjuan, CCC, November 03, 2014 » Aspiration Windows, Fail-Low
2015 ...
- Ordering of Root moves and search instability ! by Mahmoud Uthman, CCC, October 26, 2015 » Move Ordering, Search Instability
- Root search by Laurie Tunnicliffe, CCC, September 08, 2016
2020 ...
- Move ordering at the root by Jonathan McDermid, CCC, October 30, 2021 » Move Ordering - Root Node Considerations