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A [[Checkmate#MateScore|mate score]] is assigned to terminal mate [[Root|root]] position, in White relative minimax either the maximum (black mated) or minimum (white mated) values of the whole value range, in [[Side to move|side to move]] relative [[Negamax|negamax]] metric always the minimum, i.e. VALUE_MATED = -[[Word#Ranges|SHRT_MAX]]/2. Below the root the absolute values of mate scores are usually decremented by [[Ply|ply]] distance to the root, to encourage programs to prefer shorter mates if winning or longer mates if losing.
Inside a negamax based search, most <ref>[https://www.stmintz.com/ccc/index.php?id=469728 The Code for the Rybka-Mate-Bug] by [[Chrilly Donninger]], [[CCC]], December 13, 2005</ref> programs assign ''VALUE_MATED + [[Ply|ply]] distance to the root'' as worst case score if entering a [[Node|node]], which if propagated as mate score along the [[Principal variationVariation|principal variation]] to the root, translates in mate in odd plies (positive values), or getting mated in even plies.
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However, those scores need ply-adjustment if stored as [[Exact Score|exact score]] inside the [[Transposition Table|transposition table]], and re-adjustment if retrieving from TT. An alternative approach, not only related to mate scores was proposed by [[Harm Geert Muller]], the '''Delayed-loss bonus''' as implemented in [[Micro-Max]] et al. <ref>[http://home.hccnet.nl/h.g.muller/delay.html Evaluation: Aging - The Delay Penalty] from [[Micro-Max]] by [[Harm Geert Muller]]</ref> <ref>[http://www.talkchess.com/forum/viewtopic.php?topic_view=threads&p=147295&t=15129 Re: Transposition Tables] by [[Harm Geert Muller]], [[CCC]], September 26, 2007</ref> <ref>[http://www.talkchess.com/forum/viewtopic.php?t=16751 Delayed-loss-bonus discussion goes here] by [[Harm Geert Muller]], [[CCC]], September 28, 2007</ref> <ref>[http://www.talkchess.com/forum/viewtopic.php?t=31981 Seeing a promotion, but not playing it...] by [[Harm Geert Muller]], [[CCC]], January 24, 2010</ref> <ref>[http://www.talkchess.com/forum/viewtopic.php?t=58881&start=1 Re: The cause of extreme piece shuffling] by [[Harm Geert Muller]], [[CCC]], January 11, 2016</ref>.
