Chess324 (x16) is a DFRC variant with rooks and kings always at their usual starting positions (324 different starting configurations). Standard castling allows practically all engines participate. In addition, the TCEC Chess 324 events also vary with castling rights (x16). The opening classifier should be updated to include a castling rights specifier when castling rights are not "KQkq".
Some examples from Chess 324 testing event:
[FEN "rbbnkqnr/pppppppp/8/8/8/8/PPPPPPPP/RQBNKBNR w KQkq - 0 1"]
[Opening "DFRC 502:532"]
[FEN "rbqnknbr/pppppppp/8/8/8/8/PPPPPPPP/RBBQKNNR w Kq - 0 1"]
[Opening "DFRC 692:508 Kq"]
[FEN "rbqnknbr/pppppppp/8/8/8/8/PPPPPPPP/RQBNKBNR w KQq - 0 1"]
[Opening "DFRC 502:508 KQq"]
[FEN "rbqnknbr/pppppppp/8/8/8/8/PPPPPPPP/RQNNKBBR w - - 0 1"]
[Opening "DFRC 414:508 no castling"]
Chess324 (x16) is a DFRC variant with rooks and kings always at their usual starting positions (324 different starting configurations). Standard castling allows practically all engines participate. In addition, the TCEC Chess 324 events also vary with castling rights (x16). The opening classifier should be updated to include a castling rights specifier when castling rights are not "KQkq".
Some examples from Chess 324 testing event: