Changes

As encouraged by Frey and Atkin in their article "The reader with an interest in chess and programming should use this listing as starting point for developing a program" <ref>[[Peter W. Frey]], [[Larry Atkin]] ('''1978'''). ''[https://archive.org/stream/byte-magazine-1978-12/1978_12_BYTE_03-12_Life#page/n141/mode/2up Creating a Chess Player, Part 3: Chess 0.5 (continued)]''. [[Byte Magazine#BYTE312|BYTE, Vol. 3, No. 12]]</ref> , Chess 0.5 was origin of at least three other competing programs, the Austrian [[Merlin]] by [[Hermann Kaindl]], [[Helmut Horacek]], [[Marcus Wagner]] and [[Roland Schreier]], further developed in Pascal except some time critical, often called routines, which were re-written in [[CDC 6600|CDC]] [[Assembly|assembly]] by Wagner <ref>[[Werner DePauli-Schimanovich-Göttig|Werner DePauli-Schimanovich]] ('''2006'''). ''[http://www.trauner.at/buchdetail.aspx?artnr=20199541 Europolis 6]''. Informatik für Spiele und Verkehr. Extension der Mengenlehre, Herausgeber: Franz Pichler, [http://www.trauner.at/Default.aspx Universitätsverlag Rudolf Trauner], ISBN 978-3-85487-946-6, (SG7) Merlin (ein ComputerChess-Programm) s. 171 (German), [http://books.google.com/books?id=Gf4WibmHVbcC&pg=PA175&lpg=PA175&source=bl&ots=YPtaHAp3Z4&sig=DNRPh11heo8Q1zS3UOBe0qoCF-8&hl=en&ei=0GmnTMX1GMfJswaL-NivDA&sa=X&oi=book_result&ct=result&resnum=1&ved=0CBgQ6AEwAA#v=onepage&q&f=false Google Books]</ref> <ref>[[Helmut Horacek]], [[Marcus Wagner]] ('''1981'''). ''Das Schachprogramm Merlin, Verbesserung von Laufzeit-Effizient, Eröffnungsbibliothek und Bewertungsfunktion.'' 4. Tagung "Berichte aus Informatik-Instituten" (German)</ref> , the Dutch [[Chess 0.5X]] by [[Wim Elsenaar]], a [[PDP-11]] assembly port, and according to postings in [[Computer Chess Forums|rgcc]] <ref>[https://groups.google.com/d/msg/rec.games.chess.computer/3iSe8NsM024/DrW8Dzsr2tYJ Re: Byte Chess 0.5 finally available. From Byte Magazine 1978] by I Forget, [[Computer Chess Forums|rgcc]], June 02, 2005</ref> , the Finnish [[Shy]] by [[Juha Kasanen]], [[Mika Korhonen]] and [[Timo Saari]], written in [[Algol]].

Chess 0.5's [[Evaluation|evaluation]] routine '''EVALU8''' implements a [[Lazy Evaluation|lazy evaluation]] only for too worse [[Score|scores]]. If the [[Incremental Updates|incremental updated]] [[Material|material balance]] plus the maximum positional score is still less or equal than [[Alpha|alpha]] (best value two plies up BSTVL[JNTK-2]), only the material balance is assigned without further positional analysis. Otherwise '''EVALU8''' consides [[Mobility|piece mobility]] (counting attacks), [[Pawn Structure|pawn structure]], [[King Safety|king safety]] and some rook terms such as doubled rooks and [[Rook On on Seventh|rook on 7th rank]]. Differences of light minus dark positional terms are adjusted by appropriate feature weights. To make white point of view scores relative to the [[Side to move|side to move]], they are multiplied by a score factor (+1, -1) indexed by side.