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'''[[Main Page|Home]] * [[Search]] * [[Node]] * Leftmost Node'''
'''Leftmost Nodes''' are the nodes searched '''first''' from the [[Root|root]] inside a [[Depth-First|depth-first]] search approach like [[Alpha-Beta]] or [[Principal Variation Search]]. If those nodes have an even [[Ply|ply]] distance from the root, that is the same [[Side to move]], their alpha-beta Window is the same as the root window, <span style="background-color: rgb(214, 214, 214)">{rootAlpha, rootBeta}</span>. An odd ply distance implies a window of <span style="background-color: rgb(214, 214, 214)">{-rootBeta, -rootAlpha}</span> inside a [[Negamax]] framework.
Since the root window is typically wide open (except [[MTD(f)]]), either <span style="background-color: rgb(214, 214, 214)">{-oo, +oo}</span> or an [[Aspiration Windows|aspiration window]] around the score from the previous [[Iteration|iteration]] inside an [[Iterative Deepening|iterative deepening]] framework, leftmost nodes have the same wide open window and will likely increase their initial alpha to establish a [[Principal Variation|principal variation]], to return an [[Exact Score|exact score]]. The left most [[Leaf Node]] with its static heuristic value, established by the [[Evaluation|evaluation]] is the leaf with the greatest probability to influence the value of the root. In [[Principal Variation Search]], leftmost nodes are [[Node Types#PV|PV-Nodes]].
=See also=
* [[Principal Variation Search]]
* [[Root]]
'''[[Node|Up one Level]]'''
'''Leftmost Nodes''' are the nodes searched '''first''' from the [[Root|root]] inside a [[Depth-First|depth-first]] search approach like [[Alpha-Beta]] or [[Principal Variation Search]]. If those nodes have an even [[Ply|ply]] distance from the root, that is the same [[Side to move]], their alpha-beta Window is the same as the root window, <span style="background-color: rgb(214, 214, 214)">{rootAlpha, rootBeta}</span>. An odd ply distance implies a window of <span style="background-color: rgb(214, 214, 214)">{-rootBeta, -rootAlpha}</span> inside a [[Negamax]] framework.
Since the root window is typically wide open (except [[MTD(f)]]), either <span style="background-color: rgb(214, 214, 214)">{-oo, +oo}</span> or an [[Aspiration Windows|aspiration window]] around the score from the previous [[Iteration|iteration]] inside an [[Iterative Deepening|iterative deepening]] framework, leftmost nodes have the same wide open window and will likely increase their initial alpha to establish a [[Principal Variation|principal variation]], to return an [[Exact Score|exact score]]. The left most [[Leaf Node]] with its static heuristic value, established by the [[Evaluation|evaluation]] is the leaf with the greatest probability to influence the value of the root. In [[Principal Variation Search]], leftmost nodes are [[Node Types#PV|PV-Nodes]].
=See also=
* [[Principal Variation Search]]
* [[Root]]
'''[[Node|Up one Level]]'''
