Path-Dependency

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 * Path-Dependency** describes a situation when the same position gets a different value depending on a sequence of moves by which it has been reached. Whilst a few programs do this by design, within the standard alpha-beta framework path-dependency is considered undesirable, if impossible to avoid. Typical cases are:
 * the position can be treated differently if there is a chance of repetition or hitting into a fifty-move rule.
 * different move ordering can cause different result (different moves causing a cutoff), when it comes from the hash table
 * if a program uses search extensions, search depth may be different (i.e. 1. d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.Nf3 vs 1.d4 Nf6 2.c4 e6 3.Nf3 Bb4+ 4.Nc3, where only the latter triggers a check extension)
 * history-dependent heuristics, like some versions of LMR may prune different sub-trees.

=See also=
 * Graph History Interaction (GHI)
 * Transposition
 * Transposition Table
 * Repetitions
 * Fifty-move Rule

=Forum Posts=

2000 ...

 * [|"Don't trust draw score" <=Is it true?] by Teerapong Tovirat, CCC, August 08, 2001 » Repetitions, Graph History Interaction

2005 ...

 * [|path dependent evaluation] by Daniel Shawul, Winboard Forum, April 20, 2005
 * [|Re: And a still unsolved test position] by Uri Blass, CCC, June 09, 2005 » Movei
 * [|Semi-Path Dependent Hashing: a semi-useless idea] by Zach Wegner, CCC, May 24, 2008 » Transposition Table

2010 ...

 * [|Repetitions/50 moves and TT] by Sergei Markoff, CCC, September 13, 2011
 * [|Texel recipe to fix TT draws scores] by Marco Costalba, CCC, June 23, 2012 » Texel

=External Links=
 * [|Path dependence from Wikipedia]

=References= =What links here?= include page="Path-dependency" component="backlinks" limit="40"
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