Changes

The [[Search|search]] is [[Principal Variation Search|PVS]] [[Alpha-Beta|alpha-beta]] with [[Transposition Table|transposition table]] inside an [[Iterative Deepening|iterative deepening]] framework without [[Aspiration Windows|aspiration]], maintaining the [[Principal variationVariation|principal variations]] inside a "quadratic" [[Triangular PV-Table|PV-table]]. [[Selectivity|Selectivity]] is realized by [[Null Move Pruning|null move Pruning]], [[Check Extensions|check extensions]], and [[Delta Pruning|delta pruning]] in [[Quiescence Search|quiescence search]]. [[History Heuristic|History heuristic]], [[Internal Iterative Deepening|IID]], [[MVV-LVA]] in conjunction with a [[SEE - The Swap Algorithm|SEE swap routine]] improve [[Move Ordering|move ordering]] and delta pruning.

Gk's [[Evaluation|evaluation]] is rudimentary and restricts positional [[Score|scores]] in the range of plus-minus one [[Pawn|pawn]] [[Point Value|value]] - at least it is very [[Lazy Evaluation|lazy]] if the [[Material#Balance|material balance]] is outside the [[Window|alpha-beta window]] by that margin. It considers [[Center Control|center control]], [[Mobility|mobility]], [[Development|development]] and [[Evaluation of piecesPieces#Queen|too early queen]], and some [[King Safety#PawnShield|pawn shield]] and [[Castling rightsRights|castling right]] related [[King Safety|king safety]] stuff. The [[Pawn Hash Table|cached]] [[Pawn Structure|pawn structure]] evaluation takes [[Passed Pawn|passers]], [[Doubled Pawn|doubled]] and [[Isolated Pawn|isolated pawns]], and [[Defended Pawns (Bitboards)|pawns protecting each other]] into account.