Changes

'''Fat Fritz 2''' , released on February 09, 2021, is based on [[NNUE]] technology of and [[Stockfish|Stockfish 12]] with a double sized network,

Using the original Fat Fritz as 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>. While the The initial release had the 40 MiB NNUE file embedded inside the Fat Fritz 2 executable, it and was soon separated after the intervention of the Stockfish community due to a possible [[Free Software Foundation#GPL|GPL license]] violation, the Stockfish executable with source code available at [https://en.wikipedia.org/wiki/GitHub GitHub] <ref>[https://githubblog.stockfishchess.comorg/DanielUrangapost/Stockfish643239805544792064/tree/ff2 GitHub statement-on-fat-fritz- DanielUranga/Stockfish at ff22 Statement on Fat Fritz 2] by [[Daniel UrangaJoost VandeVondele]], [[Computer Chess Forums|Stockfish Blog]], February 15, 2021</ref>, and a . While the separated none GPL licensed NNUE file had a replacement on GitHub as well <ref>[https://github.com/DanielUranga/Stockfish/blob/ff2/src/FatFritz2_v1.bin Stockfish/FatFritz2_v1.bin at ff2 · DanielUranga/Stockfish · GitHub]</ref>, obviously it was not identical with weights resulting in weaker play than 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, reacted with the release of [[Stockfish|Shockfish 13]] on February 19, 2021 <ref>[https://blog.stockfishchess.org/post/643570707142492160/stockfish-13 Stockfish 13], The Stockfish Team, February 19, 2021</ref>.