Editing ChessBase (section)

==Criticism and legal issues==
ChessBase has faced criticism for allegedly using free software created by others without credit. The developers of [[Stockfish (chess)|Stockfish]], an open-source chess engine, charged that Fat Fritz 2 is a modified copy of their software (that had originally been uncredited; since rectified) and that ChessBase claims "originality where there is none".<ref>{{cite web |title=Stockfish's Statement on Fat Fritz 2 |url=https://blog.stockfishchess.org/post/643239805544792064/statement-on-fat-fritz-2 |access-date=2021-02-19}}</ref> [[Lichess]] described the same product as "a rip-off".<ref name="Lichess criticism">{{cite web |title=Fat Fritz 2 is a rip off |date=18 February 2021 |url=https://lichess.org/blog/YCvy7xMAACIA8007/fat-fritz-2-is-a-rip-off |access-date=2021-02-19}}</ref>

ChessBase responded to this criticism by adding references but claiming the new engine differs from Stockfish due to added input from the original Fat Fritz neural network<ref>{{cite web |date=11 February 2021 |title=Best of Both Worlds |url=https://en.chessbase.com/post/fat-fritz-2-best-of-both-worlds |access-date=2021-02-19 |archive-date=2021-02-21 |archive-url=https://web.archive.org/web/20210221153721/https://en.chessbase.com/post/fat-fritz-2-best-of-both-worlds |url-status=dead }}</ref>—itself claimed by Lichess to be derived closely from [[Leela Chess Zero]], another open-source initiative.<ref name="Lichess criticism" />

In July 2021, Stockfish sued ChessBase, alleging that ChessBase violated Stockfish's [[GNU General Public License]].<ref name="Stockfish Chessbase Lawsuit">{{cite web |date=2021-07-20 |title=Our lawsuit against ChessBase |url=https://stockfishchess.org/blog/2021/our-lawsuit-against-chessbase/ |accessdate=2021-07-21}}</ref> In November 2022, a settlement on that lawsuit was reached.<ref>{{cite web |date=2022-11-18 |title=ChessBase GmbH and the Stockfish team reach an agreement and end their legal dispute |url=https://stockfishchess.org/blog/2022/chessbase-stockfish-agreement/ |accessdate=2022-12-18}}</ref><ref>{{cite web |date=2022-11-21 |title=Settlement Reached in Stockfish v ChessBase |url=https://lichess.org/blog/Y3u1mRAAACIApBVn/settlement-reached-in-stockfish-v-chessbase |accessdate=2022-12-18}}</ref>