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TheKiller Move is aMove Ordering related issue.

TheKiller Move is aquiet move which caused abeta-cutoff in a siblingCut-node, or any other earlier branch in thetree with the sameply distance to theroot. Therule of thumb is to try that move early direct after a possibly availablehash move from thetransposition table and considering apparently winningcaptures. This simple but efficientmove ordering heuristic is called theKiller Heuristic. Similar to moves from thetransposition table , killers may actually save thegeneration of quiet moves at all if itfails high, but require alegality test.

See also

• Hash Move
• Killer Heuristic
• Mate Killers
• Move Ordering
• Pseudo-Legal Move
• PV-Move
• Refutation Move
• Threat Move fromnull move refutations

Forum Posts

• Killer moves byChua Kong Sian,gnu.chess, March 21, 1995
• killer moves? byDaniel Shawul,CCC, November 04, 2003
• Killer moves? by Mike Robinson,CCC, September 16, 2011
• Killer and move encoding byFabio Gobbato,CCC, August 14, 2014 »Encoding Moves
• Effectiveness of killer moves byAlex Ferguson,CCC, August 17, 2014
• TTMove legality checking ? & Killers Move Format? byMahmoud Uthman,CCC, February 08, 2017 »Hash Move
• How much ELO should I expect to gain from killer moves? by Christian Dean,CCC, July 16, 2021 »Playing Strength

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