Changes

'''Fat Fritz 2''' , released on February 09, 2021, is based on [[NNUE]] technology using [[Stockfish NNUE]] aka and [[Stockfish|Stockfish 12]] with a customized, double sized network, and thus, does running on a CPU, not require requiring expensive [[GPU]] graphic cards for game playing like its predecessor.The network was trained by [[Albert Silver]] with the help of [[Daniel Uranga]] and [[Dietrich Kappe]], who provided scripts and ideas.Further credits were given to the [[:Category:Stockfish Contributor|Stockfish contributors]], and in particular [[Yu Nasu]] for his groundbreaking work on NNUE, and [[Hisayori Noda]] for the initial [[Stockfish NNUE]] implementation <ref>[https://en.chessbase.com/post/92134 fat-fritz-2-best-of-both-worlds Fat Fritz 2: The Best of Both Worlds] by [[Albert Silver]], [[ChessBase|ChessBase News]], February 10, 2021</ref>.The network was trained by [[Albert Silver]] using Using the original Fat Fritzas initial supervisor to evaluate chess positions,the learning of Fat Fritz 2 was [[Reinforcement Learning|reinforced]] by Stockfish's [[Alpha-Beta|alpha-beta]] [[Search|search]] <ref>[https://en.chessbase.com/post/fat-fritz-2-0-the-new-number-1 Fat Fritz 2.0 - The new number 1], [[ChessBase|ChessBase News]], February 09, 2021</ref>.The initial release had the 40 MiB NNUE file embedded inside the Fat Fritz 2 executable, and was soon separated after the intervention of the Stockfish community due to a possible [[Free Software Foundation#GPL|GPL license]] violation <ref>[https://blog.stockfishchess.org/post/643239805544792064/statement-on-fat-fritz-2 Statement on Fat Fritz 2] by [[Joost VandeVondele]], [[Computer Chess Forums|Stockfish Blog]], February 15, 2021</ref>. While the separated none GPL licensed NNUE file had a replacement on GitHub <ref>[https://github.com/DanielUranga/Stockfish/blob/ff2/src/FatFritz2_v1.bin Stockfish/FatFritz2_v1.bin at ff2 · DanielUranga/Stockfish · GitHub]</ref>, it was not identical with the commercial purchased network, yielding in weaker play <ref>[http://www.talkchess.com/forum3/viewtopic.php?f=2&t=76537&start=238 Re: Fat Fritz 2] by [[Stefan Pohl]], [[CCC]], February 13, 2021</ref>. The Stockfish community, denying Fat Fritz 2's originality as claimed by ChessBase, initially reacted with the release of [[Stockfish|Stockfish 13]] on February 19, 2021 <ref>[https://blog.stockfishchess.org/post/643570707142492160/stockfish-13 Stockfish 13], The Stockfish Team, February 19, 2021</ref>. In summer 2021, the Stockfish team filed a [https://en.wikipedia.org/wiki/Lawsuit lawsuit] against [[ChessBase]] to enforce the consequences of the license termination concerning Fat Fritz 2 and the allegedly Stockfish derivative [[Houdini#Stockfish|Houdini 6]] sold by ChessBase <ref>[https://stockfishchess.org/blog/2021/our-lawsuit-against-chessbase/ Our lawsuit against ChessBase], [[Stockfish|The Stockfish team]], [[Computer Chess Forums|Stockfish Blog]], July 20, 2021</ref>.  

* [http://www.talkchess.com/forum3/viewtopic.php?f=2&t=71661 Chessbase's Albert Silver on LC0 & Fat Fritz] by supersharp77, [[CCC]], August 26, 2019

* [https://shop.chessbase.com/en/products/fat_fritz_2 Fat Fritz 2SE] - [[ChessBase|ChessBase Shop]]* [https://shop.chessbase.com/en/products/fat_fritz_2_powerbook_2021 Fat Fritz 2 SE + Fritz Powerbook 2021] - [[ChessBase|ChessBase Shop]]* [https://store.steampowered.com/app/1587750/Fat_Fritz_20_SE/ Fat Fritz 2.0 SE] on [https://en.wikipedia.org/wiki/Steam_(service) Steam]* [https://www.newinchess.com/fat-fritz-2-0 Fat Fritz 2.0 SE], [https://en.wikipedia.org/wiki/New_In_Chess New In Chess]* [https://www.houseofstaunton.com/fat-fritz-2-0.html Fat Fritz 2.0 SE], [https://en.wikipedia.org/wiki/House_of_Staunton House Of Staunton]* [https://www.uscfsales.com/fat-fritz-2-0.html Fat Fritz 2.0 SE], [https://www.uscfsales.com/ The Official Chess Shop of the US Chess Federation - Chess Pieces, Chess Sets, Chess Boards, Chess Clocks and More!]* [https://www.amazon.com/Playing-Software-Bundled-Success-Training/dp/B08W1WYXG3/ref=sr_1_1?dchild=1&keywords=Fat+Fritz+2&qid=1626991799&sr=8-1 Amazon.com: Fat Fritz 2.0 Chess Playing Software Bundled with Chess Success II Chess Training DVD: Toys & Games]

* [https://en.chessbase.com/post/fat-fritz-2-best-of-both-worlds Fat Fritz 2: The Best of Both Worlds] by [[Albert Silver]], [[ChessBase|ChessBase News]], February 1011, 2021* <span id="interview"></span>[https://en.chessbase.com/post/interview-with-albert-silver-his-journey-to-fat-fritz-2-0 Interview with Albert Silver - His journey to Fat Fritz 2.0] by [https://www.udemy.com/user/arne-kaehler/ Arne Kaehler], [[ChessBase|ChessBase News]], February 12, 2021, [https://en.wikipedia.org/wiki/YouTube YouTube] Video: {{#evu:https://www.youtube.com/watch?v=9C-E1BqzLcs|alignment=left|valignment=top}}* [https://en.chessbase.com/post/how-a-neural-network-is-made How a neural network is made] by [[Albert Silver]], [[ChessBase|ChessBase News]], February 21, 2021* <span id="StephenHam"></span>[https://en.chessbase.com/post/discussing-moves-with-a-neural-network Discussing moves with a neural network] by [[Stephen Ham]], [[ChessBase|ChessBase News]], February 27, 2021 <ref>[http://www.talkchess.com/forum3/viewtopic.php?f=2&t=76730 An actual interesting computer chess read about FF2] by [[Dietrich Kappe]], [[CCC]], February 27, 2021</ref>* [https://en.chessbase.com/post/steamrolling-the-king Steamrolling the king], [[ChessBase|ChessBase News]], June 15, 2021* [https://en.chessbase.com/post/solving-the-impossible Solving the impossible] by [[Albert Silver]], [[ChessBase|ChessBase News]], June 24, 2021

* [https://github.com/DanielUranga/Stockfish/tree/ff2 GitHub - DanielUranga/Stockfish at ff2] by [[Daniel Uranga]]: [https://github.com/DanielUranga/Stockfish/commit/e44edde482ad06154c5133173245fdd2ad48a8cc#diff-a29c7f79728b32e998f606ae6f2fd2cb7c4a654fb0cef86547335542ca8ac054R38 ff2 · DanielUranga/Stockfish@e44edde · GitHub] by : [https://github.com/DanielUranga/Stockfish/commit/faef72afbf10273ca8688a4ba1c7863426c93c6e FF2 · DanielUranga/Stockfish@faef72a · GitHub]: [Daniel Uranga]https://github.com/DanielUranga/Stockfish/blob/ff2/src/FatFritz2_v1.bin Stockfish/FatFritz2_v1.bin at ff2 · DanielUranga/Stockfish · GitHub]

* [http://ccrlwww.computerchess.chessdomorg.comuk/ccrl/404/cgi/compare_engines.cgi?family=Fritz&print=Rating+list&print=Results+table&print=LOS+table&print=Ponder+hit+table&print=Eval+difference+table&print=Comopp+gamenum+table&print=Overlap+table&print=Score+with+common+opponents Fat%20FritzFritz] in [[CCRL|CCRL Blitz]]* [http://www.computerchess.org.uk/ccrl/4040/cgi/compare_engines.cgi?family=Fritz&print=Rating+list&print=Results+table&print=LOS+table&print=Ponder+hit+table&print=Eval+difference+table&print=Comopp+gamenum+table&print=Overlap+table&print=Score+with+common+opponents Fat Fritz] in [[CCRL|CCRL Blitz40/15]]