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TheRoot of theSearch Tree is the initialposition of thesearch. Many programmers dedicate a separate function for doing a root search, since using a differentmove ordering scheme may be beneficial. Also root search must return not only the value, but also themove which will be played. This in turn may require special care in case of a fail-low when usingaspiration window. This is typically where thetime 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 byRonald de Man
• Time Management

Forum Posts

1997 ...

• computer chess "oracle" ideas... byRobert Hyatt,rgcc, April 1, 1997

Re: computer chess "oracle" ideas... byRonald de Man,rgcc, April 3, 1997

Re: computer chess "oracle" ideas... byRonald de Man,rgcc, April 7, 1997

• Failing low at the root byGuido Schimmels,CCC, August 03, 1998
• Question: Fail High then Low at Root byWilliam 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 byWilliam Bryant,CCC, February 08, 2000 »Fail-Low,Time Management
• Root move and incomplete iteration byFrank Phillips,CCC, December 11, 2000

Re: Root move and incomplete iteration byRobert Hyatt,CCC, December 11, 2000

• What means lazy/plain alpha bounding? bySeveri Salminen,CCC, February 06, 2001 »Fail-High

2005 ...

• Even more search questions bySven Schüle,Winboard Forum, July 17, 2007 »Iterative Deepening

2010 ...

• Root node search byOnno Garms,CCC, March 13, 2011 »Onno
• Root node search in Stockfish byOnno Garms,CCC, June 12, 2011 »Stockfish
• A few general questions... byBill Henry,CCC, January 29, 2012 »Exact Score,Aspiration Windows
• Pruning in PV nodes bySergei S. Markoff,CCC, January 14, 2014 »Reductions,Node Types
• Solving a fail low situation at the root byAlberto Sanjuan,CCC, November 03, 2014 »Aspiration Windows,Fail-Low

2015 ...

• Ordering of Root moves and search instability ! byMahmoud Uthman,CCC, October 26, 2015 »Move Ordering,Search Instability
• Root search byLaurie Tunnicliffe,CCC, September 08, 2016

2020 ...

• Move ordering at the root by Jonathan McDermid,CCC, October 30, 2021 »Move Ordering - Root Node Considerations

External Links

• Root from Wikipedia
• Root (disambiguation) from Wikipedia
• Ian Carr'sNucleus -Roots, 1973,YouTube Video

Up one Level

• Ian Carr
• Nucleus